Copyright Cirrus Logic, Inc. 2011
(All Rights Reserved)
http://www.cirrus.com
CS5463
Single Phase, Bi-directional Power/Energy IC
Features
Energy Data Linearity: ±0.1% of Reading
over 1000:1 Dynamic Range
On-chip Functions:
-Instantaneous Voltage, Current, and Power
-IRMS and VRMS, Apparent, Reactive, and Active
(Real) Power
-Active Fundamental and Harmonic Power
-Reactive Fundamental, Power Factor, and Line
Frequency
-Energy-to-pulse Conversion
-System Calibrations and Phase Compensation
-Temperat ur e Sen s o r
Meets accuracy spec for IEC, ANSI, JIS.
Low Power Consumption
Current Input Opti mized for Sense Resistor.
GND-referenced Signals with Single Supply
On-chip 2.5 V Reference (25 ppm/°C typ)
Power Supply Monitor
Simple Three-wire Digital Serial Interface
“Auto-boot” Mode from Serial E2PROM
Power Supply Configurations:
VA+ = +5 V; AGND = 0 V; VD+ = +3.3 V to +5 V
Description
The CS5463 is an integrated power measure-
ment device which combines two
analog-to-digital converters, power calculation
engine, energy-to-frequency converter, and a
serial interface on a single chip . It is de sign ed to
accurately measure instantaneous current and
voltage, and calculate VRMS, IRMS, instanta-
neous power, apparent power, active power, and
reactive power for single-phase, 2- or 3-wire
power metering applica tio ns.
The CS5463 is optimized to interface to shunt re-
sistors or current transformers for current
measurement, and to resi stive dividers or poten-
tial transformers for voltage measurement.
The CS5463 features a bi-directional serial inter-
face for communication with a processor and a
programmable energy-to-pulse output function.
Additional features include on-chip functionality
to facilitate system-le vel calibration, te mperature
sensor, voltage sag detection, and phase
compensation.
ORDERING INFORMATION:
See Page 45.
VA+ VD+
IIN+
IIN-
VIN+
VIN-
VREFIN
VREFOUT
AGND XIN XOUT CPUCLK DGND
CS
SDO
SDI
SCLK
INT
Voltage
Reference System
Clock /K Clock
Generator
Serial
Interface
E-to-F
Power
Monitor
PFMON
x1
RESET
Digital
Filter
Calibration
MODE
Power
Calculation
Engine
4th Order
Modulator
2nd O rder
Modulator
Temperature
Sensor
Digital
Filter
PGA
HPF
Option
HPF
Option
E1
E2
E3
x10
APR ‘11
DS678F3
CS5463
2DS678F3
TABLE OF CONTENTS
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Characteristics & Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Digital Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 Voltage and Current Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3 Power Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4 Linearity Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1.1 Voltage Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1.2 Current Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2 IIR Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 High-pass Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.4 Performing Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.5 Energy Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5.1 Active Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5.2 Apparent Energy Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5.3 Reactive Energy Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5.4 Voltage Channel Sign Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5.5 PFMON Output Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.5.6 Design Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.6 Sag and Fault Detect Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.7 No Load Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.8 On-chip Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.9 Voltage Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.10 System Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.11 Power-down States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.12 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.13 Event Handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.13.1 Typical Interrupt Handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.14 Serial Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.14.1 Serial Port Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.15 Register Paging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.16 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.16.1 Start Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.16.2 SYNC0 and SYNC1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.16.3 Power-up/Halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.16.4 Power-down and Software Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.16.5 Register Read/Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.16.6 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6. Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.1 Page 0 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.1.1 Configuration Register ( Config ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.1.2 Current and Voltage DC Offset Register ( IDCoff , VDCoff ) . . . . . . . . . . . . 27
6.1.3 Current and Voltage Gain Register ( Ign , Vgn ) . . . . . . . . . . . . . . . . . . . . 27
6.1.4 Cycle Count Register ( Cycle Count ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.1.5 PulseRateE Register ( PulseRateE ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.1.6 Instantaneous Current, Voltage, and Power Registers ( I , V , P ) . . . . . . 28
CS5463
DS678F3 3
6.1.7 Active (Real) Power Register ( PActive ) . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.8 RMS Current & Voltage Registers ( IRMS , VRMS ). . . . . . . . . . . . . . . . . . 28
6.1.9 Epsilon Register ( e ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.10 Power Offset Register ( Poff ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1.11 Status Register and Mask Register ( Status , Mask ) . . . . . . . . . . . . . . . 29
6.1.12 Current and Voltage AC Offset Register ( VACoff , IACoff ) . . . . . . . . . . . 30
6.1.13 Operational Mode Register ( Mode ). . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.1.14 Temperature Register ( T ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.1.15 Average and Instantaneous Reactive Power Register ( QAVG , Q ) . . . . 31
6.1.16 Peak Current and Peak Voltage Register ( Ipeak , Vpeak ). . . . . . . . . . . . 31
6.1.17 Reactive Power Register ( QTrig ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1.18 Power Factor Register ( PF ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1.19 Apparent Power Register ( S ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1.20 Control Register ( Ctrl ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.1.21 Harmonic Active Power Register ( PH ) . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.1.22 Fundamental Active Power Register ( PF ) . . . . . . . . . . . . . . . . . . . . . . 33
6.1.23 Fundamental Reactive Power Register ( QH ) . . . . . . . . . . . . . . . . . . . . 34
6.1.24 Page Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.2 Page 1 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.2.1 Energy Pulse Output Width ( PulseWidth ). . . . . . . . . . . . . . . . . . . . . . . . 35
6.2.2 No Load Threshold ( LoadMin ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.2.3 Temperature Gain Register ( TGain ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.2.4 Temperature Offset Register ( TOff ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.3 Page 3 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
6.3.1 Voltage Sag & Current Fault Duration Registers . . . . . . . . . . . . . . . . . . . 36
6.3.2 Voltage Sag & Current Fault Level Registers . . . . . . . . . . . . . . . . . . . . . . . 36
7. System Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.1 Channel Offset and Gain Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.1.1 Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.1.1.1 Duration of Calibration Sequence . . . . . . . . . . . . . . . . . . . . . 37
7.1.2 Offset Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.1.2.1 DC Offset Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . 37
7.1.2.2 AC Offset Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . 38
7.1.3 Gain Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.1.3.1 AC Gain Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . . 38
7.1.3.2 DC Gain Calibration Sequence . . . . . . . . . . . . . . . . . . . . . . . 39
7.1.4 Order of Calibration Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.2 Phase Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.3 Active Power Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8. Auto-boot Mode Using E2PROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.1 Auto-boot Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.2 Auto-boot Data for E2PROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.3 Which E2PROMs Can Be Used? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9. Basic Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
10. Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
11. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
12. Environmental, Manufacturing, & Handling Information . . . . . . . . . . . . . . . . . 45
13. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
CS5463
4DS678F3
LIST OF FIGURES
Figure 1. CS5463 Read and Write Timing Diagrams..................................................................12
Figure 2. Timing Diagram for E1, E2, and E3.......................................................................................13
Figure 3. Data Measurement Flow Diagram...............................................................................14
Figure 4. Power Calculation Flow. ..............................................................................................15
Figure 5. Active and Reactive Energy Pulse Outputs.................................................................17
Figure 6. Apparent Energy Pulse Outputs..................................................................................18
Figure 7. Voltage Channel Sign Pulse outputs ...........................................................................18
Figure 8. PFMON Output to Pin E3.......................................................................................................19
Figure 9. Sag and Fault Detect................................................................................................... 19
Figure 10. Oscillator Connection.................................................................................................20
Figure 11. CS5463 Memory Map................................................................................................22
Figure 12. Calibration Data Flow ................................................................................................37
Figure 13. System Calibration of Offset......................................................................................37
Figure 14. System Calibration of Gain........................................................................................38
Figure 15. Example of AC Gain Calibration................................................................................38
Figure 16. Example of AC Gain Calibration................................................................................38
Figure 17. Typical Interface of E2PROM to CS5463...................................................................40
Figure 18. Typical Connection Diagram (Single-phase, 2-wire)..................................................41
Figure 20. Typical Connection Diagram (Single-phase, 3-wire)..................................................42
Figure 19. Typical Connection Diagram (Single-phase, 2-wire – Isolated from Power Line)......42
Figure 21. Typical Connection Diagram (Single-phase, 3-wire – No Neutral Available).............43
LIST OF TABLES
Table 1. Current Channel PGA Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 2. E2 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 3. E3 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 4. Interrupt Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
CS5463
DS678F3 5
1. OVERVIEW
The CS5463 is a CMOS monolithic power measurement device with a computation engine and an ener-
gy-to-frequency pulse output. The CS5463 combines a programmable gain amplifier, two Ana-
log-to-Digital Converters (ADCs), system calibration, and a computation engine on a single chip.
The CS5463 is designed for power measurement applications and is optimized to interface to a current
sense resistor or transformer for current measurement, and to a resistive divider or potential transformer
for voltage measurement. The current channel provides programmable gains to accommodate various in-
put levels from a multitude of sensing elements. With single +5 V supply on VA+/AGND, both of the
CS5463’s input channels can accommodate common mode plus signal levels between (AGND - 0.25 V)
and VA+.
The CS5463 also is equipped with a computation engine that calculates instantaneous power, IRMS,
VRMS, apparent power, active (real) power, reactive power, harmonic active power, active and reactive
fundamental power, and power factor. The CS5463 additional features include line frequency, current and
voltage sag detection, zero-cross detection, positive-only accumulation mode, and three programmable
pulse output pins. To facilitate communication to a microprocessor, the CS5463 includes a simple
three-wire serial interface which is SPI™ and Microwire™ compatible. The CS5463 provides three out-
puts for energy registration. E1, E2, and E3 are designed to interface to a microprocessor.
CS5463
6DS678F3
2. PIN DESCRIPTION
Clock Generator
Crystal Out
Crystal In 1,24 XOUT, XIN – The output and input of an inverting amplifier. Oscillation occurs when connected to
a crystal, providing an on-chip system clock. Alternatively, an external clo ck can be supplied to
the XIN pin to provide the system clock for the device.
CPU Clock Output 2CPUCLK – Output of on-chip oscillator which can drive one standard CMOS load.
Control Pins and Serial Data I/O
Serial Clock Input 5SCLK – A Schmitt-trigger input pin. Clocks data from the SDI pin into the receive buffer and out
of the transmit buffer onto the SDO pin when CS is low.
Serial Data Output 6SDO – Serial port data output pin.SDO is forced into a high-impedance state when CS is high.
Chip Select 7CS – Low, activates the serial port interface.
Mode Select 8MODE - High, enables the “auto-boot” mode. The mode pin has an internal pull-down resistor.
Energy Output 18,21,22 E3, E1, E2 – Active-low pulses with an output frequency proportional to the selected power. Con-
figurable outputs for active, app arent, and reactive power, negative energy indication, zero cross
detection, and power failure monitoring. E1, E2, E3 outputs are configured in the Operational
Modes Register.
Reset 19 RESET – A Schmitt-trigger input pin. Low activates Reset, all internal registers (some of which
drive output pins) are set to their default states.
Interrupt 20 INT - Low, indicates that an enabled event has occurred.
Serial Data Input 23 SDI - Serial port data input pin. Data will be input at a rate determined by SCLK.
Analog Inputs/Outputs
Differential Voltage Inputs 9,10 VIN+, VIN- – Differential analog input pins for the voltage channel.
Differential Current Inputs 15,16 IIN+, IIN- – Differential analog input pins for the current channel.
Voltage Reference Output 11 VREFOUT – The on-chip voltage reference output. The voltage reference has a nominal magni-
tude of 2.5 V and is referenced to the AGND pin on the converter.
Voltage Reference Input 12 VREFIN – The input to this pin establishes the voltage reference for the on-chip modulator.
Power Supply Connections
Positive Digital Supply 3VD+ – The positive digital supply.
Digital Ground 4DGND – Digital Ground.
Positive Analog Supply 14 VA+ – The positive analog supply.
Analog Ground 13 AGND – Analog ground.
Power Fail Monitor 17PFMON – The power fail monitor pin monitors the analog supply. If the analog supply does not
meet or falls below PFMON’s voltage threshold, a Low-supply Detect (LSD) event is set in the
status register.
12
11
10
9
8
7
6
5
4
3
2
1
13
14
15
16
17
18
19
20
21
22
23
24
AGND Analog Ground
VA+ Positive Analog Supply
IIN- Differential Current Input
IIN+ Differential Current Input
PFMON Power Fail Monitor
E3 High Frequency Energy Output
RESET Reset
INT Interrupt
E1 Energy Output 1
SDI Se rial D ata Input
XIN Crysta l In
E2 Energy Output 2
VREFINVoltage Reference Input VREFOUTVoltage Reference Output VIN-Differential Voltage Input VIN+Differential Voltage Input MODEMode Select CSChip Select SDOSerial Data Ouput SCLKSerial C lock DGNDDigital Ground VD+Positive Digita l Supp ly CPUCLKCPU Clock Output XOUTCrystal Out
CS5463
DS678F3 7
3. CHARACTERISTICS & SPECIFICATIONS
RECOMMENDED OPERATING CONDITIONS
ANALOG CHARACTERISTICS
• Min / Max characteristics and specifications are guaranteed over all R ecommended Operating Conditions.
• Typical characteristics and specifications are measured at nominal supply voltages and TA = 25 °C.
• VA+ = VD+ = 5 V ±5%; AGND = DGND = 0 V; VREFIN = +2.5 V. All voltages with respect to 0 V.
• MCLK = 4.096 MHz.
Notes: 1. Applies when the HPF option is enabled.
2. Applies when the line frequen cy is equal to the p roduct of the Output Word Rate (OWR) and the value
of epsilon ().
Parameter Symbol Min Typ Max Unit
Positive Digital Power Supply VD+ 3.135 5.0 5.25 V
Positive Analog Power Supply VA+ 4.75 5.0 5.25 V
Voltage Reference VREFIN - 2.5 - V
Spec ifie d Temper a tu re Range TA-40 - +85 °C
Parameter Symbol Min Typ Max Unit
Accuracy
Active Power All Gain Ranges
(Note 1) Input Range 0.1% - 100% PActive -±0.1-%
Average Reactive Power All Gain Ranges
(Note 1 and 2) Input Range 0.1% - 100% QAvg -±0.2-%
Power Factor All Gain Ranges
(Note 1 and 2) Input Range 1.0% - 100%
Input Range 0.1% - 1.0% PF -
-±0.2
±0.27 -
-%
%
Current RMS All Gain Ranges
(Note 1) Input Range 0.2% - 100%
Input Range 0.1% - 0.2% IRMS -
-±0.2
±1.5 -
-
%
%
%
Voltage RMS All Gain Ranges
(Note 1) Input Range 5% - 100% VRMS -±0.1-%
Analog Inputs (Both Channels)
Common Mode Rejection (DC, 50, 60 Hz) CMRR 80 - - dB
Common Mode + Signal All Gain Ranges -0.25 - VA+ V
Analog Inputs (Current Channel)
Differential Input Range (Gain = 10)
[(IIN+) - (IIN-)] (Gain = 50) IIN -
-500
100 -
-mVP-P
mVP-P
Tot al Harmonic Distortion (Gain = 50) THD 80 94 - dB
Crosstalk wi th Voltage Channel at Full Scale (50, 60 Hz) - -115 - dB
Input Capacitance (Gain = 10)
(Gain = 50) IC -
-32
52 -
-pF
pF
Effective Input Impedance EII 30 - - k
Noise (Referred to Input) (Gain = 10)
(Gain = 50) NI-
-22.5
4.5 -
-µVrms
µVrms
Offset Drift (Without the High Pass Filter) OD - 4.0 - µV/°C
Gain Error (Note 3) GE - ±0.4 %
CS5463
8DS678F3
ANALOG CHARACTERISTICS (Continued)
Notes: 3. Applies before system calibration.
4. All outputs unloaded. All inputs CMOS level.
5. Measurement method for PSRR: VREFIN tied to VREFOUT, VA+ = VD+ = 5 V, a 150 mV
(zero-to-peak) (60 Hz) sinewave is imposed onto the +5 V DC supply voltage at VA+ and VD+ pins. The
“+” and “-” in pu t p ins o f b oth inpu t ch ann els are sh or te d to AGND. Then the CS5 463 is comma nded to
continuous conversion acquisition mode, and digital ou tput data is collected for the channel under test.
The (zero-to-peak) value of the digital sinusoidal output signal is determined, and this value is converted
into the (zero-to -peak) value of the sinusoidal vo ltage (measured in mV) tha t would need to be app lied
at the channel’s inp uts, in order to cause the same di gital sinusoidal output. This voltage is then defined
as Veq. PSRR is then (in dB):
6. When voltage level on PFMON is sagging, and LSD bit = 0, the voltage at which LSD is set to 1.
7. If the LSD bit has been set to 1 (b ecause PFMON voltage fell below PMLO), this is the voltage level on
PFMON at which the LSD bit can be permanently reset back to 0.
Parameter Symbol Min Typ Max Unit
Analog Inputs (V oltage Channel)
Differential Input Range [(VIN+) - (VIN-)] VIN - 500 - mVP-P
Tot al Harmonic Distortion THD 65 75 - dB
Crosstalk with Current Channel at Full Scale (50, 60 Hz) - -70 - dB
Input Capacitance All Gain Ranges IC - 0.2 - pF
Effective Input Impedance EII 2 - - M
Noise (Referred to Input) NV-140-µV
rms
Offset Drift (Without the High Pass Filter) OD - 16.0 - µV/°C
Gain Error (Note 3) GE - ±3.0 %
Temperature Chann el
Temperature Accuracy T - ±5 - °C
Power Supplies
Power Supply Currents (Active State) IA+
ID+ (VA+ = VD+ = 5 V)
ID+ (VA+ = 5 V, VD+ = 3.3 V)
PSCA
PSCD
PSCD
-
-
-
1.1
2.9
1.7
-
-
-
mA
mA
mA
Power Consumption Active State (VA+ = VD+ = 5 V)
(Note 4) Active State (VA+ = 5 V, VD+ = 3.3 V)
Stand-by State
Sleep State
PC -
-
-
-
21
11.6
8
10
29
17.5
-
-
mW
mW
mW
µW
Power Supply Rejection Ratio (50, 60 Hz)
(Note 5) Voltage Channel
Current Channel PSRR 45
70
-
65
75
-
-
-dB
dB
PFMON Low-voltage Trigger Threshold (Note 6) PMLO 2.3 2.45 - V
PFMON High-voltage Power-on Trip Point (Note 7) PMHI - 2.55 2.7 V
PSRR 20 150
Veq
----------
log=
CS5463
DS678F3 9
VOLTAGE REFERENCE
Notes: 8. The voltage at VREFOUT is measured across the temperature range. From these measurements the
following formula is used to calculate the VREFOUT Temperature Coefficient:.
9. Specified at maximum recommended output of 1 µA, source or sink.
DIGITAL CHARACTERISTICS
• Min / Max characteristics and specifications are guaranteed over all R ecommended Operating Conditions.
• Typical characteristics and specifications are measured at nominal supply voltages and TA = 25 °C.
• VA+ = VD+ = 5V ±5%; AGND = DGND = 0 V. All voltages with respect to 0 V.
• MCLK = 4.096 MHz.
Parameter Symbol Min Typ Max Unit
Reference Output
Output Voltage VREFOUT +2.4 +2.5 +2.6 V
Temperature Coefficient (Note 8) TCVREF - 25 60 ppm/°C
Load Regulation (Note 9) VR-610mV
Reference Input
Input Voltage Range VREFIN +2.4 +2.5 +2.6 V
Input Capacitance - 4 - pF
Input CVF Current - 25 - nA
Parameter Symbol Min Typ Max Unit
Master Clock Characteristics
Master Clock Frequency Internal Gate Oscillator (Note 11) MC LK 2.5 4.096 20 MHz
Master Clock Duty Cycle 40 - 60 %
CPUCLK Duty Cycle (Note 12 and 13) 40 - 60 %
Filter Characteristics
Phase Compensation Range ( Voltage Channel, 60 Hz) -2.8 - +2.8 °
Input Sampling Rate DCLK = MCLK/K - DCLK/8 - Hz
Digital Filter Output W ord Rate (Both Channels) OWR - DCLK/1024 - Hz
High-pass Filter Corner Frequency -3 dB - 0.5 - Hz
Full-scale DC Calibration Range (Referred to Input) (Note 14) FSCR 25 - 100 %F.S.
Channel-to-channel Time-shift Error (Note 15) 1.0 µs
Input/Output Characteristics
High-level Input Voltage
All Pins Except XIN and SCLK and RESET
XIN
SCLK and RESET
VIH 0.6 VD+
(VD+) - 0.5
0.8VD+
-
-
-
-
-
-
V
V
V
Low-level Input Voltage (VD = 5 V)
All Pins Except XIN and SCLK and RESET
XIN
SCLK and RESET
VIL -
-
-
-
-
-
0.8
1.5
0.2VD+
V
V
V
(VREFOUTMAX - VREFOUTMIN)
VREFOUTAVG
(
(
1
TAMAX - TAMIN
(
(
1.0 x 10
(
(
6
TCVREF =
CS5463
10 DS678F3
Notes: 10. All measurements performed under static conditions.
11. If a crystal is used, then XIN frequency must remain between 2.5 MHz - 5.0 MHz. If an external
oscillator is used, XIN frequency range is 2.5 MHz - 20 MHz, but K must be set so that MCLK is between
2.5 MHz - 5.0 MHz.
12. If external MCLK is used, then the duty cycle must be between 45% and 55% to maintain this
specification.
13. The frequency of CPUCLK is equal to MCLK.
14. The minimum FSCR is limited by the maximum allowe d gain register value. The maximum FSCR is
limited by the full-scale signal applied to the channel input.
15. Configuration Register bits PC[6 :0] are set to “0000000”.
16. The MODE pin is pulled low by an internal resistor.
Low-level Input Voltage (VD = 3.3 V)
All Pins Except XIN and SCLK and RESET
XIN
SCLK and RESET
VIL -
-
-
-
-
-
0.48
0.3
0.2VD+
V
V
V
High-level Output Voltage Iout = +5 mA VOH (VD+) - 1.0 - - V
Low-level Output Voltage Iout = -5 mA VOL --0.4V
Input Leakage Curren t (Note 16) Iin -±1±10µA
3-state Leakage Current IOZ --±10µA
Digital Output Pin Capacitance Cout -5-pF
Parameter Symbol Min Typ Max Unit
CS5463
DS678F3 11
SWITCHING CHARACTERISTICS
• Min / Max characteristics and specifications are guaranteed over all R ecommended Operating Conditions.
• Typical characteristics and specifications are measured at nominal supply voltages and TA = 25 °C.
• VA+ = 5 V ±5% VD+ = 3.3 V ±5% or 5 V ±5%; AGND = DGND = 0 V. All voltages with respect to 0 V.
• Logic Levels: Logic 0 = 0 V, Logic 1 = VD+.
Notes: 17. Specified using 10% and 90% points on waveform of interest. Output loaded with 50 pF.
18. Oscillator start-up time varies with crystal parameters. This specification does not apply when using an
external clock source.
Parameter Symbol Min Typ Max Unit
Rise Times Any Digital Input Except SCLK
(Note 17) SCLK
Any Digital Output
trise -
-
-
-
-
50
1.0
100
-
µs
µs
ns
Fall Times Any Digital Input Except SCLK
(Note 17) SCLK
Any Digital Output
tfall -
-
-
-
-
50
1.0
100
-
µs
µs
ns
Start-up
Oscillator Start-up Time XTAL = 4.096 MHz (Note 18) tost -60-ms
Serial Port Timing
Serial Clock Frequency SCLK - - 2 MHz
Serial Clock Pulse Width High
Pulse Width Low t1
t2
200
200 -
--
-ns
ns
SDI Timing
CS Falling to SCLK Rising t350 - - ns
Data Set-up Time Prior to SCLK Rising t450 - - ns
Data Hold Time After SCLK Rising t5100 - - ns
SDO Timing
CS Falling to SDI Driving t6-2050ns
SCLK Falling to New Data Bit (hold time) t7-2050ns
CS Rising to SDO Hi-Z t8-2050ns
Auto-Boot Timing
Serial Clock Pulse Width Low
Pulse Width High t9
t10
8
8MCLK
MCLK
MODE setup time to RESET Rising t11 50 ns
RESET rising to CS falling t12 48 MCLK
CS falling to SCLK rising t13 100 8 MCLK
SCLK falling to CS rising t14 16 MCLK
CS rising to driving MODE low (to end auto-boot sequence) t15 50 ns
SDO guaranteed setu p time to SCLK rising t16 100 ns
CS5463
12 DS678F3
t1t2
t3
t4t5
MSB
MSB-1
LSB
MSB
MSB-1
LSB
MSB
MSB-1
LSB
MSB
MSB-1
LSB
Command Tim e 8 S CLK s H igh B yte M id B yte Low B yte
CS
SCLK
SDI
t10 t9
RESET
SDO
SCLK
CS
Last 8
Bits
SDI
MODE
STOP bit
D a ta from E EP ROM
t16 t4t5
t14
t15
t7
t13
t12
t11
(INPUT)
(INPUT)
(OUTPUT)
(OUTPUT)
(OUTPUT)
(INPUT)
SDI Write Timing (Not to Scale)
SDO Read Timing (Not to Scale)
Figure 1. CS5463 Read and Write Timing Diagrams
Auto-boot Sequence Timing (Not to Scale)
t1t2
MSB
MSB-1
LSB
C om m and Tim e 8 SC LKs SYNC0 or SYNC1
Command S YN C 0 or SYN C1
Command
MSB
MSB-1
LSB
MSB
MSB-1
LSB
MSB
MSB-1
LSB
High B y te Mid B y te L o w B y te
CS
SDO
SCLK
SDI
t6
t7
t8
SYNC0 or SYNC1
Command
UNKNOWN
CS5463
DS678F3 13
SWITCHING CHARACTERISTICS (Continued)
Notes: 19. Pulse output timing is specified at MCLK = 4.096 MHz, E2MODE = 0, and E3MODE[1:0] = 0. Refer to
Section 5.5 Energy Pulse Output on page 17 for more information on pulse output pins.
20. Timing is proportional to the fr equency of MCLK.
ABSOLUTE MAXIMUM RATINGS
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
Notes: 21. VA+ and AGND must satisfy [(VA+) - (AGND)] + 6.0 V.
22. VD+ and AGND must satisfy [(VD+) - (AGND)] + 6.0 V.
23. Applies to all pins including continuous o ver-voltage conditions at the analog input pins.
24. Transient current of up to 100 m A will not cause SCR latch-up.
25. Maximum DC input current for a power supply pin is ±50 mA.
26. Total power dissipation, including all input currents and output currents.
Parameter Symbol Min Typ Max Unit
E1, E2, and E3 Timing (Note 19 and 20)
Period tperiod 250 - - s
Pulse Width tpw 244 - - s
Rising Edge to Falling Edge t36--s
E2 Setup to E1 and/or E3 Falling Edge t41.5 - - s
E1 Falling Edge to E3 Falling Edge t5248 - - s
Parameter Symbol Min Typ Max Unit
DC Power Supplies (Notes 21 and 22)
Positive Digital
Positive Analog VD+
VA+ -0.3
-0.3 -
-+6.0
+6.0 V
V
Input Current, Any Pin Except Supplies (Notes 23, 24, 25) IIN --±10mA
Output Current, Any Pin Except VREFOUT IOUT --100mA
Power Dissipation (Note 26) PD--500mW
Analog Input Voltage All Analog Pins VINA - 0.3 - (VA+) + 0.3 V
Digital Input Voltage All Digital Pins VIND -0.3 - (VD+) + 0.3 V
Ambient Operating Temperature TA-40 - 85 °C
Storage Temperature Tstg -65 - 150 °C
tperiod
E1 t3
t4
t5t3
t5
t4
E2
E3
tpw
tperiod
tpw
Figure 2. Timing Diagram for E1, E2, and E3
CS5463
14 DS678F3
4. THEORY OF OPERATION
The CS5463 is a dual-channel analog-to-digital convert-
er (ADC) followed by a computation engine that per-
forms power calculations and energy-to-pulse
conversion. The data flow for the voltage and current
channel measurement and the power calculation algo-
rithms are depic te d in Fig ur e 3 and 4, respe ctively.
The analog inputs are structured with two dedicated
channels, Voltage and Current, then optimized to simpli-
fy interfacing to various sensing elements.
The voltage-sensing element introduces a voltage
waveform on the voltage channe l input VIN± and is sub-
ject to a gain of 10x. A second-order d elta-sigma mo du-
lator samples the amplified sig nal for digitization.
Simultaneously, the current-sensing element introduces
a voltage waveform on the current channel input IIN±
and is subject to two selectable gains of the program-
mable gain amplifier (PGA). The amplified signal is
sampled by a fourth-order delta-sigma modulator for
digitization. Both converters sample at a rate of
MCLK/8, the over-sampling provides a wide dynamic
range and simplified anti-alias filter design.
4.1 Digital Filters
The decimating dig ital filters on both chann els are Sinc3
filters followed by 4th-order IIR filters. The single-bit
data is passed to the low-pass decimat ion filter and out-
put at a fixed word rate. The ou tput word is passed to an
optional IIR filter to compensate for the magnitude roll
off of the low-pass filtering operation.
An optional digital high-pass filter (HPF in Figure 3) re-
moves any DC component from the selected signal
path. By removing the DC component from the voltage
and/or the current channel, any DC content will also be
removed from the calcu lated active power as we ll. With
both HPFs enabled the DC component will be removed
from the calculated VRMS and IRMS as well as the appar-
ent power.
When the optional HPF in either channel is disabled, an
all-pass filter (APF) is implemented. The APF has an
amplitude response that is flat within the channel ba nd-
width and is used for matching phase in syste ms where
only one HPF is engaged.
4.2 Voltage and Current Measurements
The digital filter output word is then subject to a DC off-
set adjustment and a gain calibration (See Section 7.
System Calibration on page 37). The calibrated mea-
surement is available by reading the instantaneous volt-
age and current registers.
The Root Mean Square (RMS in Figure 4) calculations
are performed on N instantaneous voltage and current
samples, Vn and In, respectively (where N is the cycle
count), using the formula:
and likewise for VRMS, using Vn. IRMS and VRMS are ac-
cessible by register reads, which are updated once ev-
ery cycle count (referred to as a computational cycle).
4.3 Power Measurements
The instantaneous voltage and current samples are
multiplied to obtain the instantaneous power (see Fig-
ure 3). The product is then averaged over N conver-
sions to compute active power and is used to drive
energy pulse output E1. Energy output E2 is selectable,
providing an energy sign or a pulse output that is pro-
portional to the apparent power. Energy output E3
VOLTAGE SINC3+X
V*
gn
CURRENT SINC3+X
I*
gn
DELAY
REG
DELAY
REG
IDCoff*
VDCoff*
PGA +
+
Configuration Register *
Digital Filter
Digital Filter
HPF
2nd Order
Modulator
4th Order
Modulator
x10 X
X
SYSGain*
PC6 PC5 PC4 PC3 PC2 PC1 PC0
6
*DENOTES REGISTER NAME.
DELAY
REG
DELAY
REG
HPF VQ
*
XVDEL XIDEL 012
2322 87
...
Operational Modes Register *
+
X
+
X
XQ*
2
MUX
X
V*
P*
I*
MUX
VHPF IHPF
65
*
APF
HPF
APF
MUX
IIR
MUX
IIR
3
IIR
4
Figure 3. Data Measureme nt Flow Diagram.
IRMS In
n0=
N1–
N
---------------------
=
CS5463
DS678F3 15
provides a pulse output that is proportional to the reac-
tive power or apparent power. Output E3 can also be set
to display the sign of the voltage applied to the voltage
channel or the PFMON comparator output.
The apparent power (S) is the combination of the active
power and reactive power, without reference to an im-
pedance phase angl e, and is calcu lated by the CS546 3
using the following formula:
Power Factor (PF) is the active power (PActive) divided
by the apparent power (S)
The sign of th e power factor is de termined by the active
power.
The CS5463 calculates the reactive power, QTrig utiliz-
ing trigonometric identities, giving the formula
Average reactive power, QAvg, is generated by averag-
ing the voltage multiplied by the current with a 90° phase
shift difference between them. The 90 ° phase shift is re-
alized by applying an IIR digital filter in the voltage chan-
nel to obtain quadrature voltage (see Figure 3). This
filter will give exactly -90° phase shift across all frequen-
cies, and utilizes epsilon () to achieve unity g ain at th e
line frequency.
The instantaneous qu adrature vo ltage (V Q) and curr ent
(I) samples are multiplied to obtain the instantaneous
quadrature power (Q). The product is then averaged
over N conversions, utilizing the formula
Fundamental active (PF) and reactive (QF) power is cal-
culated by performing a discrete Fourier transform
(DFT) at the relevant frequency on the instantaneous
voltage (V) and cu rrent (I). Epsilon is used to set the fre-
quency of the internal sine (imaginary component) and
cosine (real component) waveform generator. The har-
monic active power (P H) is calculated by subtracting the
fundamental active power (PF) from the active power
(PActive).
The peak current (Ipeak) and peak voltage (Vpeak) are
the instantaneous current and voltage, respectively,
with the greatest magnitude detected during the last
computation cycle. Active, apparent, reactive, and fun-
damental power are updated every computation cycle.
4.4 Linearity Performance
The linearity of the VRMS, IRMS, active, reactive, and
power-factor power measurements (before calibration)
will be within ±0.1% of reading over the ranges speci-
fied, with respect to the input voltage levels required to
cause full-scale readings in the IRMS and VRMS regis-
ters. Refer to Accuracy Specifications on page 7.
Until the CS5463 is calibrated, the accuracy of the
CS5463 (with respect to a reference line-voltage and
line-current level on the power mains) is not guaranteed
to within ±0.1%. (See Section 7. System Calibration on
page 37.) The accuracy of the internal calculations can
often be improved by selecting a value for the Cycle
Count Register that will cause the time duration of one
computation cycle to be equal to (or very close to) a
whole number of power-line cycles (and N must be
greater than or eq ual to 4000).
X
V*
I*
RMS
V*
RMS
E1
I*
Energy-to-pulseXE3
+
+
X
+
IACoff*
+
+
VACoff*
+
E2
N
÷
N
N
÷
N
P*
ACTIVE
N
÷
N
P
off*
P*
PulseRate*
*DENOT ES REGISTER NA M E.
X
S*
Q*
AVG
-
+
X
Inverse XPF*
QTRIG
*
Q*N
÷
N
X
Figure 4. Power Calculation Flow.
SV
RMS IRMS
=
PF PActive
S
------------------
=
QTrig S2PActive
2
–=
QAvg
Qn
n1=
N
N
-------------------------
=
CS5463
16 DS678F3
5. FUNCTIONAL DESCRIPTION
5.1 Analog Inputs
The CS5463 is equipped with two fully differential input
channels. The inpu ts VIN and IIN are designated as
the voltage and current channel inputs, respectively.
The full-scale differential input voltage for the current
and voltage channel is 250 mVP.
5.1.1 Voltage Channel
The output of the line voltage resistive divider or trans-
former is connected to the VIN+ and VIN- input pins of
the CS5463. The voltage channel is equipped with a
10x fixed-gain amplifier. The full-scale signal level that
can be applied to the voltage channel is 250 mV. If the
input signal is a sine wave the maximum RMS voltage
at a gain 10x is:
which is approximately 70.7% of maximum peak volt-
age. The voltage channel is also equipped with a Volt-
age Gain Register, allowing for an additional
programmable gain of up to 4x.
5.1.2 Current Channel
The output of the current-sense resistor or transformer
is connected to the IIN+ and IIN- input pins of the
CS5463. To accommodate different current sensing el-
ements the curr ent channel inco rporates a programma-
ble gain amplifier (PGA) with two programmable input
gains. Co nfiguration Register bit Igain (see Table 1) de-
fines the two gain selections and corresponding maxi-
mum input-signal level.
For example, if Igain=0, the current channel’s PGA gain
is set to 10x. If the input si gna ls are p ure sinu soids with
zero phase shift, the maximum peak differential signal
on the current or voltage channel is 250 mVP. The in-
put signal levels are ap proximately 70.7% of maximum
peak voltage producing a full-scale energy pulse regis-
tration equal to 50% of absolute maxi mum energy pulse
registration. This will be discussed further in See Sec-
tion 5.5 Energy Pulse Output on page 17.
The Current Gain Register also facilitates an additional
programmable gain of up to 4x. If an additional gain is
applied to the voltage and/or curr ent cha nnel, the ma xi-
mum input range should be adjusted accordingly.
5.2 IIR Filters
The current and voltage channel are equipped with a
4th-order IIR filter, that is used to compensate for the
magnitude roll off of the low-pass decimation filter. Op-
erational Mode Register bit IIR engages th e IIR filters in
both the volta ge and current channels.
5.3 High-pass Filters
By removing the offset from either channel, no error
component will be generated at DC when computing the
active power. By removing the offset from both chan-
nels, no error component will be generated at DC when
computing VRMS, IRMS, and apparent power. Operation-
al Mode Register bits VHPF and IHPF activate the HPF
in the voltage and current ch annel respectively. When a
high-pass filter is active in only one channel, a n all-pass
filter (APF) is applied to the othe r channel. The APF has
an amplitude response that is flat within the channel
bandwidth and is used for matching phase in systems
where only one HPF is engaged.
5.4 Performing Measurements
The CS5463 performs measurements of instantaneous
voltage (Vn) and current (In), and calculates instanta-
neous power (Pn) at an output word rate (OWR) of
where K is the clock divider selected in the Configura-
tion Register.
The RMS voltage (VRMS), RMS current (IRMS), and ac-
tive power (Pactive) are computed using N instantaneous
samples of Vn, In, and Pn respectively, where N is the
value in the Cycle Count Register and is referred to as
a “computation cycle”. The apparent power (S) is the
product of VRMS and IRMS. A computation cycle is de-
rived from the master clock (MCLK), with frequency:
Under default conditions and with K = 1, N = 4000, and
MCLK = 4.096 MHz – the OWR = 4000 Hz and the
ComputationCycle= 1Hz.
All measurements are available as a percentage of full
scale. The format for signed registers is a two’s comple-
ment, normalized value between -1 and +1. The format
Igain Maximum Input Range
0±250mV10x
1 ±50 mV 50x
Table 1. Current Channel PGA Setting
250mVP
2
--------------------- 176.78mVRMS
OWR MCLK K
1024
-----------------------------
=
Computation Cycle OWR
N
---------------
=
CS5463
DS678F3 17
for unsigned re gisters is a n ormalized value betw een 0
and 1. A register value of
represents the maximum possible value.
At each instantaneous measurement, the CRDY bit will
be set in the Status Register, and the INT pin will be-
come active if the CRDY bit is unmasked in the Mask
Register. At the end of each computation cycle, the
DRDY bit will be set in the Status Register, and the INT
pin will become active if the DRDY bit is unmasked in
the Mask Register. When these bits are asserted, they
must be cleared before they can be asserted again.
If the Cycle Count Register (N) is set to 1, all output cal-
culations are instantaneous, and DRDY, like CRDY, will
indicate when instantaneous measurements are fin-
ished. Some calculations are inhibited when the cycle
count is less than 2.
Epsilon () is the ratio of the input line frequency (fi) to
the sample frequency (fs) of the ADC.
where fs= MCLK / (K*1024). With MCLK = 4.096 MHz
and clock divider K = 1, fs= 4000 Hz. For the two
most-common line frequencies, 50 Hz and 60 Hz
and
respectively. Epsilon is used to set the frequency of the
internal sine/cosine reference for the fundamental ac-
tive and reactive measureme nts, and the gain of the 90°
phase shift (IIR) filter for the average reactive power.
5.5 Energy Pulse Output
The CS5463 provides three output pins for energy reg-
istration. By default, E1 registe rs active energ y, E3 reg-
isters reactive energy, and E2 indicates the sign of both
active and reactive energy. (See Figure 2. Timing Dia-
gram for E1, E2, and E3 on page13.) The E1 pu lse out-
put is designed to register the Active Energy. The E2 pin
can be set to register Ap parent Energy. Table 2 defines
the pulse output mode, which is controlled by bit
E2MODE in the Operational Mode Regi ster.
The E3 pin can be set to register Reactive Energy (de-
fault), PFMON, Voltage Channel Sign, or Apparent En-
ergy. Table 3 defines the pulse output format, which is
controlled by bits E3MODE[1:0] in the Operational
Mode Register.
The pulse output frequency o f E1, E2, and E3 is directly
proportional to the power calculated from the input sig-
nals. The value contained in the PulseRateE Register is
the ratio of the frequency of energy-outpu t pulses to the
number of sample s, at full scale, which defines th e av-
erage frequency for th e ou tp ut pulses. The pulse width,
tpw in Figure 2, is programmable through the Pulse-
Width register, and is approximately equal to:
If MCLK = 4.096 MHz, K = 1, and PulseWidth = 1, then
tpw 0.25 ms.
5.5.1 Active Energy
The E1 pin produces active-low pulses with an output
frequency proportional to the active power. The E2 pin
is the energy direction indicator. Positive energy is rep-
resented by E1 pin falling while the E2 is high. Neg ative
energy is represented by the E1 pin falling while the E2
is low. The E1 and E2 switching characteristics are
specified in Figure 2. Timing Diagram for E1, E2, and E3
on page13.
Figure 5 illustrates the pulse output format with positive
active energy and negative re active energy.
223 1–
223
------------------------0.99999988
=
fifs
=
50 Hz 4000 Hz0.0125==
60 Hz 4000 Hz0.015==
E2MODE E2 Output Mode
0 Sign of Energy
1 Apparent Energy
Table 2. E2 Pin Configuration
E3MODE1 E3MODE0 E3 OutPut Mode
0 0 Reactive Energy
01 PFMON
1 0 Voltage Channel Sign
1 1 Apparent Energy
Table 3. E3 Pin Configuration
tpw secPulseWidth 1
( MCLK/K ) / 1024
------------------------------------------------
E3
E2
E1
Figure 5. Active and Reactive energy pulse outputs
CS5463
18 DS678F3
The pulse output frequency of E1 is directly proportional
to the active power calculated from the input signals. To
calculate the output frequency of E1, the following trans-
fer function can be utilized:
With MCLK = 4.096 MHz, PF = 1, and default settings,
the pulses will have an average frequency equal to the
frequency specified by PulseRate when the input sig-
nals applied to the voltage and current channels cause
full-scale readings in the instantaneous voltage and cur-
rent registers. The maximum pulse frequency from the
E1 pin is (MCLK/K)/2048.
5.5.2 Apparent Energy Mode
Pin E2 outputs apparent ener gy pulses when th e Oper-
ational Mode Register bit E2MODE = 1. Pin E3 ou tput s
apparent energy pulses when the Operational Mode
Register bits E3MODE[1:0] = 3 (11b). Figure 6 illus-
trates the pulse output format with apparent energy on
E2 (E2MODE = 1 and E3MODE[ 1:0 ] = 0)
The pulse output freque ncy of E2 (and/o r E3) is directly
proportional to the apparent power calculated from the
input signals. Since apparent power is without reference
to an impedance phase angle, the following transfer
function can be utilized to calculate the output frequency
on E2 (and/or E3).
With MCLK = 4.096 MHz and default settings, the puls-
es will have an average frequency equal to the frequen-
cy specified by PulseRate when the input signals
applied to the voltage and current channels cause
full-scale readings in the instantaneous voltage and cur-
rent registers. The maximum pulse frequency from the
E2 (and/or E3) pin is (MCLK / K) /2048. The E2 (and/or
E3) pin outputs apparent energy, but has no energy di-
rection indicator.
5.5.3 Reactive Energy Mode
Reactive energy pulses are output on pin E3 by setting
bit E3MODE[1:0] = 0 (def ault) in the Operational Mode
Register. Positive reactive energy is registered by E3
falling when E2 is high. Negative reactive energy is reg-
istered by E3 falling when E2 is low. Figure 5 on
page 17 illustrates the pulse output format with negative
reactive energy o utput on pin E3 and th e sign of the en-
ergy on E2. The E3 and E2 pulse output switching char-
acteristics are specified in Figure 2 on page 13.
The pulse output frequency of E3 is directly proportional
to the reac tive power calcula ted from the in put signals.
To calculate the output frequency on E3, the following
transfer function can be utilized:
With MCLK = 4.096 MHz, PF = 0 and default settings,
the pulses will have an average frequency equal to the
frequency specified by PulseRate when the input sig-
nals applied to the voltage and current channels cause
full-scale readings in the instantaneous voltage and cur-
rent registers. The maximum pulse frequency from the
E1 pin is (MCLK/K)/2048.
5.5.4 Voltage Channel Sign Mode
Setting bits E3MODE[1:0] = 2 (10b) in the Operational
Mode Register outputs the sign of the voltage channel
on pin E3. Figure 7 illustrates the output format with volt-
age channel sign on E3
FREQP = Average frequency of active energy E1 pulses [Hz]
VIN = rms voltage across VIN+ and VIN- [V]
VGAIN = Voltage channe l gain
IIN = rms voltage across IIN+ and IIN- [V]
IGAIN = Current channel gain
PF = Power Factor
PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]
VREFIN = Voltage at VREFIN pin [V]
FREQPVIN VGAINIINIGAIN PF PulseRate
VREFIN2
---------------------------------------------------------------------------------------------------------------------------------=
E3
E2
E1
Figure 6. Apparent energy pulse out puts
FREQS = Average frequency of apparent energy E2 and/or E3 pulses [Hz]
VIN = rms voltage across VIN+ and VIN- [V]
VGAIN = Voltage channe l gain
IIN = rms voltage across IIN+ and IIN- [V]
IGAIN = Current channel gain
PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]
VREFIN = Voltage at VREFIN pin [V]
FREQSVIN VGAINIINIGAIN PulseRate
VREFIN2
------------------------------------------------------------------------------------------------------------------=
FREQQ = Average frequency of reactive energy E3 pulses [Hz]
VIN = rms voltage across VIN+ and VIN- [V]
VGAIN = Voltage channe l gain
IIN = rms voltage across IIN+ and IIN- [V]
IGAIN = Current channel gain
PQ =
PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]
VREFIN = Voltage at VREFIN pin [V]
FREQQVIN VGAINIINIGAIN PQ PulseRate
VREFIN2
----------------------------------------------------------------------------------------------------------------------------------=
1PF
2
–
E3
E2
E1
Figure 7. Voltage Channel Sign Pulse outputs
CS5463
DS678F3 19
Output pin E3 is high when the line voltage is positive
and pin E3 is low when the line voltage is negative.
5.5.5 PFMON Output Mode
Setting bit E3MODE[1:0] = 1 (01b) in the Operational
Mode Register outputs the state of the PFMON compar-
ator on pin E3. Figure 8 illustrates the output format with
PFMON on E3
When PFMON is greater then the threshold, pin E3 is
high and when PFMON is less tha n the threshold pin E3
is low.
5.5.6 Design Example
EXAMPLE #1:
The maximum rated levels for a power line meter are
250 V rms and 20 A rms. The required number of puls-
es-per-second on E1 is 100 pulses per second
(100 Hz), when the levels on the power line are
220 V rms and 15 A rms.
With a 10x gain on the voltage and current channel the
maximum input signal is 250 mVP. (See Section 5.1 An-
alog Inputs on page 16.) To prevent over-driving the
channel inputs, the maxim um rated rms inpu t levels will
register 0. 6 in VRMS and IRMS by design. Therefore the
voltage level at the channel inputs will be 150 mV rms
when the maximum rated levels on the power lines are
250 V rms and 20 A rms.
Solving for PulseRate using the transfer function:
Therefore wi th PF = 1 and:
the pulse rate is:
and the PulseRateE Register is set to:
with MCLK = 4.096 MHz and K = 1.
5.6 Sag and Fault Detect Feature
Status bit VSAG and IFAULT in the Status Register, in-
dicates a sag occurred in the power line voltage and
current, respectively. For a sag condition to be identi-
fied, the absolute value of the instantaneous voltage or
current must be less than the sag level for more than
half of the sag duration (see Figure 9).
To activate voltage sag detection, a voltage sag level
must be specified in the Voltage Sag Level Register
(VSAGLevel), and a voltage sag duration must be spec-
ified in the Voltage Sag Duration Register (VSAGDura-
tion). To activate current fault detection, a current sag
level must be specified in the Current Fault Level Reg-
ister (ISAGLevel), and a current sag duration must be
specified in the Current Fault Dur ation R egister (ISAG-
Duration). The voltage and current sag levels are speci-
fied as the average of the absolute instantaneous
voltage and current, respectively. Voltage and current
sag duration is specified in terms of ADC cycles.
5.7 No Load Threshold
The No Load Threshold register (LoadMin) is used to
disable the active energy pulse output when the ma gni-
tude of the PActive register is less than the value in the
LoadMin register.
5.8 On-chip Temperature Sensor
The on-chip temper ature sensor is designed to assist in
characterizing the measurement element over a desired
temperature range. Once a temperature characteriza-
tion is performed, the temperature sensor can then be
utilized to assist in compensating for temperature drift.
Temperature measurements are performed during con-
tinuous conversions and stored in the Temperature
Register. The Temperature Register (T) default is Cel-
sius scale (°C). The Temperature Gain Register (Tgain)
and Temperature Offset Register (Toff) are constant val-
ues allowing for temperature scale conversions.
E3
E2
E1
Above PFM ON Threshold Below PFM O N Threshold
Figure 8. PFMON output to pin E3
PulseRate FREQPVREFIN2
VIN VGAINIINIGAIN PF
---------------------------------------------------------------------------------------------
=
VIN 220V 150mV250V132mV==
IIN 15A 150mV20A112.5mV==
PulseRate 100 2.52
0.132 100.112510
----------------------------------------------------------------- 420.8754Hz==
PulseRateE PulseRate
MCLK K
2048
----------------------------------------0.2104377
==
Level
Duration
Figure 9. Sag and Fault Detect
CS5463
20 DS678F3
The temperature update r ate is a function of the number
of ADC samples. With MCLK = 4.096 MHz and K = 1
the update rate is:
The Cycle Count Register (N) must be set to a value
greater then one. Status bit TUP in the Status Register,
indicates when the Temperatur e Reg ister is updated.
The Temperature Offset Register sets the zero-degree
measurement. To improve temperature measurement
accuracy, the zero-degree offset may need to be adjust-
ed after the CS5463 is initialized. Temperature-offset
calibration is achieved by adjusting the Temperature
Offset Register (Toff) by the differential temperature
(T) measured from a calibrated digital thermometer
and the CS5463 tempera ture sensor. A one-de gree ad-
justment to the Temperature Register (T) is achieved by
adding 2.737649x10-4 to the Temperature Offset Regis-
ter (Toff). Therefore,
if Toff = -0.0951126 and T = -2.0 (°C), then
or 0xF3C168 (2’s compliment notation) is stored in the
Temperat ur e Of fse t R egi ste r (Toff).
To convert the Temperature Register (T) from a Celsius
scale (°C) to a Fahrenheit scale (°F) utilize the formula
Applying the above relationship to the CS5461A tem-
perature measurement algorithm
If Toff = -0.09566 and Tgain = 23.507 for a Celsius scale,
then the modified values are Toff = -0.09079
(0xF460E1) and Tgain = 42.3132 (0x54A05E) for a
Fahrenheit scale.
5.9 Voltage Reference
The CS5463 is specified for operatio n with a +2.5 V ref-
erence between the VREFIN and AGND pins. To utilize
the on-chip 2.5 V reference, connect the VREF OUT pin
to the VREFIN pin of the device. The VREFIN can be
used to connect external filtering and/or references.
5.10 System Initialization
Upon powering up, the digital circuitry is held in reset
until the analog voltage reaches 4.0 V. At that time, an
eight-XIN-clock-period delay is enabled to allow the os-
cillator to stabilize. The CS5463 will then initialize.
A hardware reset is initiated when the RESET pin is as-
serted with a minimum pulse width of 50 ns. The RE-
SET signal is asynchronous, with a Schmitt-trigger
input. Once the RESET pin is de-asserted, an
eight-XIN-clock-period delay is enabled
.
A software reset is initiated by writing the command
0x80. After a hardware or software reset, the internal
registers (some of which drive output pins) will be reset
to their default values. Status bit DRDY in the Status
Register, indicates the CS5463 is in its active state and
ready to receive commands.
5.11 Power-down States
The CS5463 has two p ower-down states, Stand-by and
Sleep. In the stand-by state all circuitry except the volt-
age reference and crystal oscillator is turned off. To re-
turn the device to the active state, a power-up command
is sent to the device.
In Sleep state, all circuitry except the instr uction decod-
er is turned off. When the power-up command is sent to
the device, a system initialization is performed (See
Section 5.10 System Initialization on page 20).
5.12 Oscillator Characteristics
XIN and XOUT are the input and output of an inverting
amplifier configured as an on-chip oscillator, as shown
in Figure 10. The oscillator circuit is designed to work
with a quartz crystal. To re duce circuit cost, two load ca-
pacitors C1 and C2 are integrated in the device, from
XIN to DGND, and XOUT to DGND. PCB trace lengths
should be minimized to reduce stray capacitance. To
2240 samples
MCLK K
1024
----------------------------------------0.56 sec=
Toff Toff T 2.737649 10 4–
+=
Toff 0.0951126–2.0–2.737649 10 4–
+0.09566–==
F
o9
5
---C
o17.7778+
=
TF
o
9
5
---Tgain
TC
o
Toff 17.7778 2.73764910 4
–
+
+=
Oscillator
Circuit
DGND
XIN
XOUT
C1
C1 = 22 pF
C2
C2 =
Figure 10. Oscillator Connection
CS5463
DS678F3 21
drive the device from an external clock source, XOUT
should be left unconnected while XIN is driven by the
external circuitry. There is an amplifier between XIN and
the digital section which provides CMOS level signals.
This amplifier works with sinusoidal inputs so ther e are
no problems with slow edge times.
The CS5463 can be driven by an external oscillator
ranging from 2.5 to 20 MHz, but the K divider value must
be set such that the internal MCLK will run somewhere
between 2.5 MHz and 5 MHz. The K divider value is set
with the K[3:0] bits in the Configuration Register. As an
example, if XIN = MCLK = 15 MHz, and K is set to 5,
DCLK will equal 3 MHz, which is a valid value for DCLK.
5.13 Event Handler
The INT pin is used to indicate that an internal error or
event has taken place in the CS54 63. Writing a logic 1
to any bit in the Mask Register allows the correspo nding
bit in the Status Register to activa te the I NT pin. The in -
terrupt conditio n is cl ea re d by writing a log i c 1 to the bit
that has been set in the Status Register.
The behavior of the INT pin is controlled by the IMODE
and IINV bits of the Configuration Register.
If the interrupt output signal format is set for either falling
or rising edge, the duration of the INT pulse will be at
least one DCLK cycle (DCLK = MCLK/K).
5.13.1 Typical Interrupt Handler
The steps below show how interr upts can be handled.
INITIALIZATION:
1) All Status bits are cleared by writing 0xFFFFFF to
the Status Register.
2) The condition bits which will be used to generate
interrupts are then set to logic 1 in the Mask Reg-
ister.
3) Enable interrupts.
INTERRUPT HANDLER ROUTINE:
4) Read the Status Register.
5) Disable all interrupts.
6) Branch to the proper interrupt service routine.
7) Clear the Status Register by writing b ack the read
value in step 4.
8) Re-enable interrupt
9) Return from interru pt service routine.
This handshaking procedure ensures that any new in-
terrupts activated between steps 4 and 7 are not lost
(cleared) by step 7.
5.14 Serial Port Overview
The CS5463 incorporates a serial port transmit and re-
ceive buffer with a command decoder that interprets
one-byte (8-b it) co mma nds as they are re ceived. Th ere
are four types of commands: instructions, synchroniz-
ing, register writes, and register reads (See Section
5.16 Commands on page 23).
Instructions are one byte in length and will interrupt any
instruction currently executing. Instructions do not affect
register reads currently being transmitted.
Synchronizing commands are one byte in length and
only affect the serial interface. Synchronizing com-
mands do not affect operations currently in progress.
Register writes must be followed by three bytes of data.
Register reads can re turn up to four bytes of data.
Commands and data ar e transferred most-significant bit
(MSB) first. Figure 1 on page 12, defines the serial port
timing and required sequence necessary for writing to
and reading from the serial port receive and transmit
buffer, respectively. While reading data from the serial
port, commands and data can be written simultaneous-
ly. Starting a new register read command while data is
being read will terminate the current read in progress.
This is acceptable if the remainder of the current read
data is not needed. Duri ng data reads, the serial port re-
quires input data. If a new command and data is not
sent, SYNC0 or SYNC1 must be sent.
5.14.1 Serial Port Interface
The serial port interf ace is a “4-wire” synchronous seria l
communications interface. The interface is enabled to
start excepting SCLKs when CS (Chip Select) is assert-
ed (logic 0). SCLK (Serial bit-clock) is a Schmitt-trigger
input that is used to strobe the data on SDI (Serial Data
In) into the receive buffer and out of the transmit buffer
onto SDO (Serial Data Out).
IMODE IINV INT Pin
0 0 Active-low Leve l
0 1 Active-high Level
10 Low Pulse
11 High Pulse
Table 4. Interrupt Configuration
CS5463
22 DS678F3
If the serial port interface becomes unsynchronized with
respect to the SCLK input, any attempt to clock valid
commands into the serial interface may result in unex-
pected operation. Therefor, the serial port interface
must then be re-initialized by one of the following ac-
tions:
-Drive the CS
pin high, then low.
- Hardware Reset (drive RESET pin low for at
least 10 µs).
- Issue the Serial Port Initialization Sequence,
which is 3 (or more) SYNC1 command bytes
(0xFF) followed by one SYNC0 command byte
(0xFE).
If a re-synchronization is necessary, it is best to re-ini-
tialize the part either by hardware or software reset
(command 0x80), as the state of the part may be un-
known.
5.15 Register Paging
Read/write commands access one of the 32 registers
within a specified page. By default, Pag e = 0. To access
registers in another page, the Page Register (address
0x1F) must be written with the desired page number.
Example:
Reading register 6 in page 3.
1. Write 3 to page register with command and data:
0x7E 0x00 0x00 0x03
2. Read register 6 with command:
0x0C 0xFF 0xFF 0xFF
0xFFF
0x000
0x3FF
Hardw are Reg isters*
32 Pages
Software Register*
32 Pages
ROM
2048 Words
0x400
0x7FF
0x800
Pages
0x40 - 0x7F
Pages
0x20 - 0x3F
Pages
0 - 0x1F
* Accessed using register read/w rite comm ands.
Figure 11. CS5463 Memory Map
CS5463
DS678F3 23
5.16 Commands
All commands are 8 bits in length. Any command byte value that is not listed in this section is invalid. Commands
that write to registers must be followed by 3 bytes of data. Commands that read data can be ch ained with other com-
mands (e.g ., while read ing da ta, a n ew command can be sen t which can execute du ring the o riginal rea d). All com-
mands except register reads, register writes, and SYNC0 & SYNC1 will abort any currently executing commands.
5.16.1 Start Conversions
Initiates acquiring measurements and calculating results. The device has two modes of acquisition.
C3 Modes of acquisition/measurement
0 = Perform a single computation cycle
1 = Perform continuous computation cycles
5.16.2 SYNC0 and SYNC1
The serial port can be initialized by asserting CS or by sending three or more consecutive SYNC1 commands fol-
lowed by a SYNC0 command. The SYNC0 or SYNC1 can also be sent while sending data out.
SYNC 0 = Last byte of a serial port re-initialization sequence.
1 = Used during reads and serial port initialization.
5.16.3 Power-up/Halt
If the device is powered-down, Power-Up/Halt will initiate a power on reset. If the part is already powered-on, all
computations will be halted.
5.16.4 Power-down and Software Reset
To conserve power the CS5463 has two power-do wn states. In stand- by state all circuitry, except the analog/digital
clock generators, is turned off. In the sleep state all circuitry, except the command decoder, is turned off. Bringing
the CS5463 out of sleep state requires more time than out of stand-by state, because of the extra time needed to
re-start and re-stabilize the analog oscillator.
S[1:0] Power-down state
00 = Software Reset
01 = Halt and enter stand- by po we r sa ving sta te . Th is stat e allo ws qu ick po we r- on
10 = Halt and enter sleep power saving state.
11 = Reserved
B7 B6 B5 B4 B3 B2 B1 B0
1110C3000
B7 B6 B5 B4 B3 B2 B1 B0
1111111SYNC
B7 B6 B5 B4 B3 B2 B1 B0
10100000
B7 B6 B5 B4 B3 B2 B1 B0
100S1S0000
CS5463
24 DS678F3
5.16.5 Register Read/Write
The Read/Write informs the command decoder that a register access is required. During a read operation, the ad-
dressed register is loaded into an output buffer and clocked out by SCLK. During a write operation, the data is
clocked into an input buffer and transferr ed to the addressed register upon completion of the 24th SCLK.
W/R Write/Read control
0 = Read
1 = Write
RA[4:0] Register address bits (bits 5 through 1) of the read/write command.
Register Page 0
Address RA[4:0] Name Description
0 00000 Config Configuration
1 00001 IDCoff Current DC Offset
2 00010 Ign Current Gain
3 00011 VDCoff Voltage DC Offset
4 00100 Vgn Voltage Gain
5 00101 Cycle Count Number of A/D conversions used in one computation cycle (N)).
6 00110 PulseRateE Sets the E1, E2 and E3 energy-to-frequency output pulse rate.
7 00111 I Instantaneous Current
8 01000 V Instantaneous Voltage
9 01001 P Instantaneous Power
10 01010 PActive Active (Real) Power
11 01011 IRMS RMS Current
12 01100 VRMS RMS Voltage
13 01101 (Epsilon) Ratio of line frequency to output word rate (OWR)
14 01110 Poff Power Offset
15 01111 Status Status
16 10000 IACoff Current AC (RMS) Offset
17 10001 VACoff Voltage AC (RMS) Offset
18 10010 Mode O peration Mode
19 10011 T Temperature
20 10100 QAVG Average Reactive Power
21 10101 Q Instantaneous Reactive Power
22 10110 IPeak Peak Current
23 10111 VPeak Peak Voltage
24 11000 QTrig Reactive Power calculated from Power Triangle
25 11001 PF Power Factor
26 11010 Mask Interrupt Mask
27 11011 S Apparent Power
28 11100 Ctrl Control
29 11101 PHHarmonic Active Power
30 11110 PFFundamental Active Power
31 11111 QFFundamental Reactive Power / Page
Note: For proper operation, do not attempt to write to unspecified registers.
B7 B6 B5 B4 B3 B2 B1 B0
0W/R
RA4 RA3 RA2 RA1 RA0 0
CS5463
DS678F3 25
Register Page 1
Address RA[4:0] Name Description
0 00000 PulseWidth Energy Pulse Output Width
1 00001 LoadMin No Load Threshold
2 00010 TGain Temperatur e Sen so r Ga in
3 00011 Toff Temperatur e Sen so r Of fse t
Register Page 3
Address RA[4:0] Name Description
6 00110 VSAGDuration Voltage sag sample interval
7 00111 VSAGLevel Voltage sag level
10 01010 ISAGDuration Current fault sample interval
11 01011 ISAGLevel Current fault level
Note: For proper operation, do not attempt to write to unspecified registers.
5.16.6 Calibration
The CS5463 can perfo rm system calibrations. Proper input signa ls must be applied to the curre nt and voltage chan-
nel before performing a de signated calibration.
CAL[4:0]* Designates calibration to be performed
01001 = Current channel DC offset
01010 = Current channel DC gain
01101 = Current channel AC offset
01110 = Current channel AC gain
10001 = Voltage channel DC offset
10010 = Voltage channel DC gain
10101 = Voltage channel AC offset
10110 = Voltage channel AC gain
11001 = Current and Voltage channel DC offset
11010 = Current and Voltage channel DC gain
11101 = Current and Voltage cha nnel AC offset
11110 = Current and Voltage channel AC gain
*For proper operation, values for CAL[4:0] not specified should not be used.
B7 B6 B5 B4 B3 B2 B1 B0
1 1 0 CAL4 CAL3 CAL2 CAL1 CAL0
CS5463
26 DS678F3
6. REGISTER DESCRIPTION
1. “Default” = bit status after power-on or reset
2. Any bit not labeled is Reserved. A zero should always be used when writing to one of these bits.
6.1 Page 0 Registers
6.1.1 Configuration Register ( Config )
Address: 0
Default = 0x000001
PC[6:0] Phase compensation. A 2’s comp lement number which sets a de lay in the voltage channel rel-
ative to the curr ent channe l. Defa ult setting is 0 000000 = 0.0215 degree phase delay at 60 Hz
(when MCLK = 4.09 6 MH z). See Sec t io n 7.2 Phase Compensation on page 39 for more infor-
mation.
Igain Sets the gain of the current PGA.
0 = Gain is 10 (default)
1 = Gain is 50
EWA Allows the E1 and E2 pins to be configured as open-collector output pins.
0 = Normal outputs (default)
1 = Only the pull-down device of the E1 and E2 pins are active
IMODE, IINV Interrupt configuration bits. Select the desired pin beh avior for indication of an interrupt.
00 = Active-low level (default)
01 = Active-high level
10 = High-to-low pulse
11 = Low-to-high pulse
iCPU Inverts the CPUCLK clock. In order to reduce the level of noise present when analog signals
are sampled, the logic dr ive n by CPUC LK sh ould not be activ e du rin g the samp le edge.
0 = Normal operation (default)
1 = Minimize noise when CPUCLK is driving rising edge logic
K[3:0] Clock divider. A 4-bit binary number used to divide the value of MCLK to generate the internal
clock DCLK. The internal clock frequency is DCLK = MCLK/K. The value of K can range be-
tween 1 and 16. Note that a value of “0000” will set K to 16 (not zero). K = 1 at reset.
23 22 21 20 19 18 17 16
PC6 PC5 PC4 PC3 PC2 PC1 PC0 Igain
15 14 13 12 11 10 9 8
EWA - - IMODE IINV - - -
76543210
- - -iCPUK3K2K1K0
CS5463
DS678F3 27
6.1.2 Current and Voltage DC Offset Register ( IDCoff , VDCoff )
Address: 1 (Current DC Offset); 3 (Voltage DC Offset)
Default = 0x000000
The DC Offset registers (IDCoff,VDCoff) are initialized to 0.0 on reset. When DC Offset calibration is performed, the
register is updated with the DC offset measured over a computation cycle. DRDY will be set at the end of the
calibration. This register may be read and stored for future system offset compensation. The value is repr esent-
ed in two's complement notation and in the range of -1.0 IDCoff,V
DCoff 1.0, with the binary point to th e right of
the MSB. See Section 7.1.2.1 DC Offset Calibration Sequence on page 37 for more information.
6.1.3 Current and Voltage Gain Register ( Ign , Vgn )
Address: 2 (Current Gain); 4 (Voltage Gain)
Default = 0x400000 = 1.000
The gain regi sters (Ign,Vgn) are initialized to 1.0 on reset. When either a AC or DC Gain calibration is performed,
the register is updated with the gain measured over a computation cycle. DRDY will be set at the end of the
calibration. This register may be r ead and stored for future system gain compensation . The value is in the range
0.0 Ign,Vgn < 3.9999, with the binary point to the right of the secon d MSB.
6.1.4 Cycle Count Register ( Cycle Count )
Address: 5
Default = 0x000FA0 = 4000
Cycle Count, denoted as N, determines the length of one computation cycle. During continuous conversions,
the computation cycle frequency is (MCLK/K)/(1024N). A one second computational cycle period occurs when
MCLK = 4.096 MHz, K = 1, and N = 4000.
6.1.5 PulseRateE Register ( PulseRateE )
Address: 6
Default = 0x800000 = 1.00 (2 kHz @ 4.096 MHz MCLK)
PulseRateE sets the frequency of E1, E2, & E3 pulses. E1, E2, E3 frequency = (MCLK x PulseRateE) / 2048 at
full scale. For a 4 khz sample rate, the maximum pulse rate is 2 khz. The value is re pr esente d in two's comple-
ment notation and in the range is -1.0 PulseRateE 1.0, with the binary point to the right of the MSB. Negative
values have the same effect as positive. See Section 5.5 Energy Pu lse Output on page 17 for more informa tion.
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
21202-1 2-2 2-3 2-4 2-5 2-6 ..... 2-16 2-17 2-18 2-19 2-20 2-21 2-22
MSB LSB
223 222 221 220 219 218 217 216 ..... 26252423222120
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
28 DS678F3
6.1.6 Instantaneous Current, Voltage, and Power Registers ( I , V , P )
Address: 7 (Instantaneous Current); 8 (Instantaneous Voltage ); 9 (Instantaneous Power)
I and V contain the instantaneous measured values for current and voltage, respectively. The instantaneous
voltage and current samples are multiplied to obtain Instantaneous Power (P). The value is represented in two's
complement notation and in th e range of -1.0 I, V, P 1.0, with the binary point to the right of the MSB.
6.1.7 Active (Real) Power Register ( PActive )
Address: 10 (Active Power)
The instantaneous power is averaged over each computation cycle (N conversions) to compute Active Power
(PActive). The value will be within in the range of -1.0 PActive1.0. The value is represented in two's complement
notation, with the binary point to the right of the MSB.
6.1.8 RMS Current & Voltage Registers ( IRMS , VRMS )
Address: 11 (IRMS); 12 (VRMS)
IRMS and VRMS contain the Root Mean Square (RMS) values of I and V, calculated each computation cycle. The
value is represented in unsigned binary notation and in the range of 0.0 IRMS,V
RMS 1.0, with the binary point
to the left of the MSB.
6.1.9 Epsilon Register (
)
Address: 13
Default = 0x01999A = 0.0125 sec
Epsilon () is the ratio of the input line frequency to the sample fr equency of the ADC (See Section 5.4 Perform-
ing Measurements on page 16). Epsilon is either written to the register, or measured during conversions. The
value is represented in two's complement notation and in the range of -1.0 1.0, with the binary point to the
right of the MSB. Negative values have no significance.
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 ..... 2-18 2-19 2-20 2-21 2-22 2-23 2-24
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
DS678F3 29
6.1.10 Power Offset Register ( Poff )
Address: 14
Default = 0x000000
Power Offset (Poff) is added to the instantaneous power being accumulated in the Pactive registe r, and can be
used to offset contributions to the energy result that are caused by undesirable sources of energy that are in -
herent in the system. The value is represented in two's complement notation and in the range of -1.0 Poff 1.0,
with the binary point to the right of the MSB.
6.1.11 Status Register and Mask Register ( Status , Mask )
Address: 15 (Status Register); 26 (Mask Register)
Default = 0x800001 (Status Register), 0x000000 (Mask Register)
The Status Register indicates status within the chip. In normal operation, writing a '1' to a bit will cause the bit
to reset. Writing a '0' to a bit will not change it’s current state.
The Mask Register is used to co ntrol the activation of the INT pin. Placing a logic '1' in a Mask bit will allow the
correspond in g bit in th e Sta tu s Register to activate the INT pin when the status bit is asserted.
DRDY Data Ready. During conversions, this bit will indicate the end of computation cycles. For cali-
brations, this bit indicates the end of a calibration sequence.
CRDY Conversion Ready. Indicates a new conversion is ready. This will occur at the output word rate.
IOR Current Out of Range. Set when the Instantaneous Current Register overflows.
VOR Voltage Out of Range. Set when the Instantaneous Voltage Register overflows.
IROR IRMS Out of Range. Set when the IRMS Register overflows.
VROR VRMS Out of Range. Set when the VRMS Register overflows.
EOR Energy Out of Range. Set when PACTIVE overflows.
IFAULT Indicates a curr ent faul t has occurr ed. See Section 5.6 Sag an d Fault Detect Fe ature on page
19.
VSAG Indicates a voltage sag has occurred. See Section 5.6 Sag and Fault Detect Feature on page
19.
TUP Temperature Updated. Indicates the Temperat ur e Re gist er has updated.
TOD Modulator oscillation detected on the temperature channel. Set when the modulator oscillates
due to an input above full scale.
VOD (IOD) Modulator oscillation detected on the voltage (current) channel. Set when the modulator oscil-
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
23 22 21 20 19 18 17 16
DRDY CRDY IOR VOR
15 14 13 12 11 10 9 8
IROR VROR EOR IFAULT VSAG
76543210
TUP TOD VOD IOD LSD FUP IC
CS5463
30 DS678F3
lates due to an input above full scale. The level at which the modulator oscillates is significantly
higher than the voltage channel’s differential input voltage (current) range.
Note: The IOD and VOD bits may be ‘falsely’ triggered by very brief voltage spikes from the
power line. This event should no t be confused with a DC overload situation at the inputs,
when the IOD and VOD bits will re-assert themselves even after being cleared, multiple
times.
LSD Low Supply Detect. Set when the voltage at th e PFMON pin falls below the low-voltage thresh-
old (PMLO), with respect to AGND pin. The LSD bit cannot be reset until the voltage at PFMON
pin rises back above the high-voltage threshold (PMHI).
FUP Epsilon Updated. Indicates completion of a line frequency measurement and update of Epsilon.
IC Invalid Command. Normally logic 1. Set to logic 0 if an invalid command is received or the Sta-
tus Register has not been succ es sfu lly re ad .
6.1.12 Current and Voltage AC Offset Register ( VACoff , IACoff )
Address: 16 (Current AC Offset); 17 (Voltage AC Offset)
Default = 0x000000
The AC Offset Registers (VACoff, IACoff) are initialized to zero on reset, allowing for uncalibrated normal operation .
AC Offset Calibration updates these registers. This sequence lasts approximately (6N + 3 0) ADC cycles (where
N is the value of the Cycle Count Register). DRDY will be asserted at the end of the calibration. These values
may be read and stored fo r future system AC offset compensation. The value is represented in two's comple-
ment notation in the range of -1.0 VACoff, IACoff 1.0, with the binary point to the right of the MSB
6.1.13 Operational Mode Register ( Mode )
Address: 18
Default = 0x000000
E2MODE E2 Output Mode
0 = Energy Sign (default)
1 = Apparent Power
XVDEL Enables an ex tra sample of voltage channel delay. XVDEL and XIDEL can not be enabled at
the same time.
XIDEL Enables an extra sample of current channel delay. XVDEL and XIDEL can not be enable d at
the same time.
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
23 22 21 20 19 18 17 16
15 14 13 12 11 10 9 8
E2MODE XVDEL
76543210
XIDEL IHPF VHPF IIR E3MODE1 E3MODE0 POS AFC
CS5463
DS678F3 31
IHPF (VHPF) Enables the high-pass filter on the current (voltage) channel.
0 = High-pass filter disabled (default)
1 = High-pass filter enabled
Note: When either IHPF or VHPF are enabled, but not both, an all-pass filter is applied to the
opposite channel for phase matching.
IIR Enables the IIR compensation filters.
0 = IIR compensation filters enabled (default)
1 = IIR compensation filters disabled
E3MODE[1:0] E3 Output Mode
00 = Reactive Power (default)
01 = PFMON
10 = Voltage sign
11 = Apparent Power
POS Positive Energy Only. Negative energy pulses on E1 are suppressed. However, it will NOT sup-
press negative P Register results.
AFC Enables automatic line-frequency measurement and sets the frequency of the local sine/cosine
generator used in fundament al/harmonic measurements. When AFC is enabled, the Epsilon
register will be updated periodically.
6.1.14 Temperature Register ( T )
Address: 19
T contains measurements from the on-chip temperature sensor. Measurements are performed during continu-
ous conversions, with the default the Celsius scale (oC). The value is represente d in two's complement notation
and in the range of -128.0 T128.0, with the binary point to the right of the eighth MSB.
6.1.15 Average and Instantaneous Reactive Power Register ( QAVG , Q )
Address: 20 (Average Reactive Power) and 21 (Instantaneous Reactive Power)
The Instantaneous Reactive Power (Q) is the pr oduct of the voltage, shifted 90 degrees, and the current. The
Average Reactive Po wer (QAVG) is Q averaged over N samples. The r esults are signed va lues with. The value
is represented in two's complement notation and in the range of -1.0 Q, QAVG1.0, with the binary point to the
right of the MSB.
6.1.16 Peak Current and Peak Voltage Register ( Ipeak , Vpeak )
Address: 22 (Peak Currect) and 23 (Peak Voltage)
The Peak Current (Ipeak) and Pea k Voltage (Vpeak) registers contain the instantaneous curr ent and voltage with
the greatest magnitude detected during the last computation cycle. The value is represented in two's comple-
ment notation and in the range of -1.0 Ipeak,V
peak 1.0, with the binary point to the right of the MSB.
MSB LSB
-(27)2
6252423222120..... 2-10 2-11 2-12 2-13 2-14 2-15 2-16
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
32 DS678F3
6.1.17 Reactive Power Register ( QTrig )
Address: 24
The Reactive Power (Q Trig) is calculated using trigonometric identitie s. (See Section 4.3 Power Measurem ents
on page 14). The value is represented in u nsigned notation and in the rang e of 0 S1.0, with the binary point
to the right of the MSB.
6.1.18 Power Factor Register ( PF )
Address: 25
Power Factor is calculated by dividing the Active (Real) Power by Apparent Power. The valu e is represented in
two's complement notation and in the range of -1.0 PF 1.0, with the binary point to the right of the MSB.
6.1.19 Apparent Power Register ( S )
Address: 27
Apparent power (S) is the product of the VRMS and IRMS, The value is re pre sented in u nsigned notatio n an d in
the range of 0 S1.0, with the binary point to the right of the MSB.
MSB LSB
02-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
02-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
DS678F3 33
6.1.20 Control Register ( Ctrl )
Register Address: 28
Default = 0x000000
STOP Term inates the auto-boot sequence.
0 = Normal (default)
1 = Stop sequence
INTOD Converts INT output pin to an open drain output.
0 = Normal (default)
1 = Open drain
NOCPU Saves power by disabling the CPUCLK pin.
0 = Normal (default)
1 = Disables CPUCLK
NOOSC Saves power by disabling the crystal oscillator.
0 = Normal (default)
1 = Disabling oscillator circuit
6.1.21 Harmonic Active Power Register ( PH )
Address: 29
The Harmonic Active Power (PH) is calculated b y subtr acting the Fundamental Active Power from the Active
(Real) Power. The value is represented in two's complement notation and in the range of -1.0 PH1.0, with
the binary point to the right of the MSB.
6.1.22 Fundamental Active Power Register ( PF )
Address: 30
The Fundamenta l Active Po wer (P F) is calculated by performing a discrete Fourie r tran sform ( DFT) at the r ele-
vant frequency on the V and I channels. The r esults are multiplied to yield fundamental powe r. The value is rep-
resented in two's complement notation and in the range of -1.0 PH1.0, with the binary point to the right of
the MSB.
23 22 21 20 19 18 17 16
15 14 13 12 11 10 9 8
STOP
76543210
INTOD NOCPU NOOSC
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
34 DS678F3
6.1.23 Fundamental Reactive Power Register ( QH )
Address: 31 (read only)
Fundamental Reactive Power (QH) is calculated by performing a discrete Fourier transform (DFT) at the relevant
frequency on the V and I channe ls. The value is r epre sented in two' s complem ent no tation a nd in the ra ng e of
-1.0 QH1.0, with the binary point to the right of the MSB.
6.1.24 Page Register
Address: 31 (write only)
Default = 0x00
Determines which register page the serial port will access.
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
26252423222120
CS5463
DS678F3 35
6.2 Page 1 Registers
6.2.1 Energy Pulse Output Width ( PulseWidth )
Address: 0
Default = 1
PulseWidth sets the duration of energy pulses (tPW). The actual pulse dur at ion is the con te n ts of Pu lseWidth
divided by the output word rate (OWR). PulseWidth is an integer in the range of 1 to 8388607.
6.2.2 No Load Threshold ( LoadMin )
Address: 1
Default = 0
LoadMin is used to set the no load threshold. When the magnitude of the PActive register is less than LoadMin,
the active energy pulse output will be disabled. LoadMin is a two's complement value in the range of
-1.0 LoadMin1.0, with the binary point to the right of the MSB. Negative values are not used.
6.2.3 Temperature Gain Register ( TGain )
Address: 2
Default = 0x2F03C3 = 23.5073471
Sets the temperature channel ga in. Temp eratur e ga in (T Gain) is utilized to convert from one temperature scale
to another. The Celsius scale (oC) is the default. Values will be within in the range of 0 TGain 128. The va lue
is represented in unsigned notation , with the binary point to the right of bit 7th MSB. See Section 5.8 On-chip
Temperature Sensor on pa ge 19.
6.2.4 Temperature Offset Register ( TOff )
Address: 3
Default = 0xF3D35A = -0.0951126
Temperature offset (Toff) is used to remove the temperature channel’s offset at the zero-degree reading. Values
are represented in two's complement notation and in the range of -1.0 Toff 1.0, with the binary point to the
right of the MSB.
MSB LSB
02
22 221 220 219 218 217 216 ..... 26252423222120
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
MSB LSB
262524232221202-1 ..... 2-11 2-12 2-13 2-14 2-15 2-16 2-17
MSB LSB
-(20)2
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
36 DS678F3
6.3 Page 3 Registers
6.3.1 Voltage Sag and Current Fault Duration Registers ( VSAGDuration , ISAGDuration )
Address: 6 (Voltage Sag Duration); 10 (Current Fault Duration)
Default = 0x000000
Voltage Sag Duration (VSAGDuration) and Current Fault Duration (ISAGDuration) defines the number of instanta-
neous measurements utilized to determine a sag event. Setting these register to zero will disable this feature.
The value is represented in unsigned notation. See Section 5.6 Sag and Fault Detect Feature on page 19.
6.3.2 Voltage Sag and Current Fault Level Registers ( VSAGLevel , ISAGLevel )
Address: 7 (Voltage Sag Level ); 11 (Current Fault Level )
Default = 0x000000
Voltage Sag Level (VSAGLevel) and Current Fault Level (ISAGLevel) d efines the voltage level that the magnitude
of input samples, averaged over the sag duration, must fall below in order to register a sag/fault condition. These
value are represented in unsigne d notation and in the range of 0 VSAGLevel 1.0, with the binary point to the
right of the third MSB. See Section 5.6 Sag and Fault Detect Feature on page 19.
MSB LSB
0222 221 220 219 218 217 216 ..... 26252423222120
MSB LSB
02
-1 2-2 2-3 2-4 2-5 2-6 2-7 ..... 2-17 2-18 2-19 2-20 2-21 2-22 2-23
CS5463
DS678F3 37
7. SYSTEM CALIBRATION
7.1 Channel Offset and Gain Calibration
The CS5463 provides digital DC offset and gain com-
pensation that can be applied to the instantaneous vo lt-
age and current measurements, and AC offset
compensat ion to the voltage an d current RMS calcula-
tions.
Since the voltage and current channels ha ve ind epe n-
dent offset and gain registers, system offset and/or
gain can be performed on either channel without the
calibration results from one ch annel affecting the oth-
er.
The computational flow of the calibration sequences are
illustrated in Figure 12. The flow applies to both the volt-
age channel and current channel.
7.1.1 Calibration Sequence
The CS5463 must be operating in its active state and
ready to accept valid commands. Refer to Section 5.16
Commands on page 23. The calibration algorithms are
dependent on the value N in the Cycle Count Register
(see Fig ure 12). Upon completion, the results of the cal-
ibration are available in their corresponding register.
The DRDY bit in the Status Register will be set. If the
DRDY bit is to be ou tput on th e INT pin, then DRDY bit
in the Mask Register must be set. The initial values in
the AC gain and offset registers do affect the results of
the calibration results.
7.1.1.1 Duration of Calibration Sequence
The value of the Cycle Count Register (N) determines
the number of conversions performed by the CS5463
during a given calibration sequence. For DC offset and
gain calibrations, the calibration sequence takes at least
N + 30 conversion cycles to complete. For AC offset cal-
ibrations, the sequence takes at least 6N + 30 ADC cy-
cles to complete, (about 6 computation cycles). As N is
increased, the accuracy of calibration results will in-
crease.
7.1.2 Offset Calibration Sequence
For DC and AC offset calibrations, the VIN pins of the
voltage and IIN pins of the current channels should be
connected to their ground reference level. (see Figure
13.)
The AC offset registers must be set to the default
(0x000000).
7.1.2.1 DC Offset Calibration Sequence
Channel gain should be set to 1.0 when performing DC
offset calibration. Initiate a DC offset calibration. The DC
offset registers are updated with the negative of the av-
erage of the instantaneous samples collected over a
computational cycle. Upon completion of the DC offset
calibration t he DC offset is stor ed in the corresp onding
DC offset register. The DC offset value will be added to
Figure 12. Calibration Data Flow
In Modulator +X
to V*, I* R e g is te r s
Filter
N
VRMS*, IRMS*
Registers
DC Offset* Gain*
0.6
+
+
+
* Denotes readable/writable register
N
+
X
N
Inverse
X
-1
RMS
AC Offs et*
N
X
-1
+
+
-
XGAIN
+
-
External
Connections
0V
+
-AIN+
AIN-
CM
+
-
Figure 13. System Calibration of Offset
CS5463
38 DS678F3
each instantaneous measurement to nullify the DC
component present in the system during conversion
commands.
7.1.2.2 AC Offset Calibration Sequence
Corresponding offset registers IACoff and/or VACoff
should be cleared prior to initiating AC offset calibra-
tions. Initiate an AC offset calibration .The AC offset reg-
isters are updated with an offset value that reflects the
RMS output level. Upon completion of the AC offset cal-
ibration the AC offset is stored in the corresponding AC
offset register. The AC offset register value is subtract-
ed from each successive VRMS and IRMS calculation.
7.1.3 Gain Calibration Sequence
When performing gain calibrations, a reference signal
should be applied to the VIN pins of the voltage and
IIN pins of the current channe ls that represents the de-
sired maximum signal level. Figure 14 shows the basic
setup for gain calibration.
For gain calibrations, there is an absolute limit on the
RMS voltage levels that are selected for the gain cali-
bration input signals. The maximum value that the gain
registers can a ttain is 4. Therefore, if the signal level of
the applied input is low enough that it causes the
CS5463 to attempt to set either gain register higher than
4, the gain calibration result will be invalid and all
CS5463 results obtained while performing measure-
ments will be invalid.
If the channel gain registers are initially set to a gain oth-
er then 1.0, AC gain calibration should be used.
7.1.3.1 AC Gain Calibration Sequence
The corresponding gain register should be set to 1.0,
unless a different initial gain value is desired. Initiate an
AC gain calibration. The AC gain calibration algorithm
computes the RMS value of the reference signal applied
to the channel inputs. The RMS register value is then di-
vided into 0.6 and the quotient is stored in the corre-
sponding gain register. Each instantaneous
measurement will be multiplied by its corresponding AC
gain value.
A typical rms calibration value which allows for reason-
able over-range margin would be 0.6 or 60% of the volt-
age and current channel’s maximum input voltage level.
Two examples of AC gain calibration and the updated
digital output codes of the cha nnel’s instantaneous data
registers are shown in Figures 15 and 16. Figure 16
shows that a positive (or negative) DC-level signal can
be used even though a n AC gain calibration is being ex-
ecuted.
+
-
+
-
External
Connections
IN+
IN-
CM +
-
+
-XGAIN
Reference
Signal
Figure 14. System Calibration of Gain.
VRMS Register = 230/ x 1/250 0.65054
250 mV
230 mV
0 V
-230 mV
-250 mV
0.9999...
0.92
-0.92
-1.0000...
VRMS Register =0.600000
250 mV
230 mV
0 V
-230 mV
-250 mV
0.84853
-0.84853
Before AC Gain Calibration (Vgn Register = 1)
After A C G ain Calibration (Vgn Register changed to approx. 0.9223)
Instantaneous Voltage
Register Values
Instantaneous Voltage
Register Values
Sinewave
Sinewave
0.92231
-0.92231
INPUT
SIGNAL
INPUT
SIGNAL
Figure 15. Example of AC Gain Calibration
VRMS Register = 230 =0.92
250 mV
230 mV
0 V
-250 mV
0.9999...
0.92
-1.0000...
VRMS Register =0.600000
250 mV
230 mV
0 V
-250 mV
0.6000
Before AC Gain Calibration (Vgain Register = 1)
After AC Gain Calibration (Vgain Register changed to approx. 0.65217)
Instantaneous Voltage
Register Values
Instantaneous Voltage
Register Values
DC Signal
DC Signal
0.65217
-0.65217
INPUT
SIGNAL
INPUT
SIGNAL
250
Figure 16. Example of AC Gain Calibration
CS5463
DS678F3 39
However, an AC signal cannot be used for DC gain cal-
ibration.
7.1.3.2 DC Gain Calibration Sequence
Initiate a DC gain calibration. The corresponding gain
register is restore d to default (1.0). The DC gain calibra-
tion averages the channel’s instantaneous measure-
ments over one computation cycle (N samples). The
average is then divided into 1.0 and the quotient is
stored in the corres po nd in g ga in re gister
After the DC gain calibration, the instantaneou s register
will read at full-scale whenever the DC leve l of the input
signal is equal to the level of the DC calibration signal
applied to the inputs during the DC gain calibration.The
HPF option should not be enabled if DC gain calibration
is utilized.
7.1.4 Order of Calibration Sequences
1. If the HPF option is enabled, then any DC component
that may be present in the selected signal path will be
removed and a DC offset calibration is not require d.
However, if the HPF option is disabled the DC offset
calibration sequence should be perfo rmed.
When using high-pass filters, it is re comme nded that
the DC Offset register for the corresponding channel
be set to zero. When performing DC offset calibra-
tion, the corresponding gain channel should be set to
one.
2. If there is an AC offset in the VRMS or IRMS calcula-
tion, then the AC offset calibration sequence should
be perfor m ed .
3. Perfor m th e ga in ca libr at ion seq ue n ce.
4. Finally, if an AC offset calibration was performed
(step 2), then the AC offset may need to be adjusted
to compensate for the change in gain (step 3). This
can be accomplished by restoring zero to the AC off-
set register and then perform an AC offset calibration
sequence. The adjustment could also be done by
multiplying the AC offset register value that was cal-
culated in step 2 by the ga in calculat ed in step 3 and
updating the AC offset register with the product.
7.2 Phase Compensation
The CS5463 is equipped with phase compensation to
cancel out phase shifts introduced by the me asurement
element. Phase Compensation is set by bits PC[6:0] in
the Configuration Register and bits XVDEL and XIDEL
in the Operational Mode Register
The default value of PC[6:0], XVDEL, and XIDEL is ze-
ro. With MCLK = 4.096 MHz and K = 1, the phase com-
pensation has a range of 8.1 degrees when the input
signals are 60 Hz. Under these conditions, each step of
the phase compensation register (value of one LSB) is
approximately 0.04 degrees. For values of MCLK other
than 4.096 MHz, the range and step size should be
scaled by 4.096 MHz/(MCLK/K). For power line fre-
quencies other than 60Hz, the values of the range and
step size of the PC[6:0] bits can be determined by con-
verting the above values from angular measurement
into the time domain ( seconds), and then computing the
new range and step size ( in degrees) with respect to the
new line frequency. To calculate the phase shift induced
between the voltage and the current channel use the
equation:
7.3 Active Power Offset
The Power Offset Register can be used to offset system
power sources that may be resident in the system, but
do not originate from the power line signal. These sourc-
es of extra energy in the system contribute undesirable
and false offsets to the powe r and energy measurement
results. After determining the amount of stray power, the
Power Offset Register can be set to cancel the effects
of this unwanted energy.
Freq = Line F r equency [Hz]
XDEL = XVDEL or -XIDEL
Phase Freq 360o
PC 5:0 PC 6 64–XDEL 128+
MCLK K8
---------------------------------------------------------------------------------------------------------------------------------
=
CS5463
40 DS678F3
8. AUTO-BOOT MODE USING E2PROM
When the CS5463 MODE pin is asserted (logic 1), the
CS5463 auto-boot mode is enab led. In auto-boot mode,
the CS5463 downloads the required commands and
register data from an external serial E2PROM, allowing
the CS5463 to begin performing energy measurements.
8.1 Auto-boot Configuration
A typical auto-boot serial connection between the
CS5463 and a E2PROM is illustrated in Figure 17. In au-
to-boot mode, the CS5463’s CS and SCLK are config-
ured as outputs. The CS5463 asserts CS (logic 0),
provides a clock on SCLK, and sends a read command
to the E2PROM on SDO. The CS5463 reads the us-
er-specified commands and register data presented on
the SDI pin. The E2PROM’s programmed data is utilized
by the CS5463 to change the designated registers’ de-
fault values and beg in re gistering energy .
Figure 17 also shows the external connections that
would be made to a calibrator device, such as a PC or
custom calibration board. When the metering system is
installed, the calibrator would be used to contro l calibra-
tion and/or to program user-specified commands and
calibration values into the E2PROM. The user-specifie d
commands/data will determine the CS5463’s exact op-
eration, when the auto-boot initialization sequence is
running. Any of the valid commands can be used.
8.2 Auto-boot Data for E2PROM
Below is an example code set for an auto-boot se-
quence. This code is written into the E2PROM by the us-
er. The serial data for such a seque nce is shown below
in single-byte hexidecimal notation:
-64 00 00 60
Write Operation Mode Register, turn high-pass
filters on.
-44 7F C4 A9
Write value of 0x7FC4A9 to Current Gain
Register.
-48 FF B2 53
Write value of 0xFFB253 to Voltage Gain
Register.
-74 00 00 04
Unmask bit #2 (LSD) in the Mask Register.
-E8
Start continuous conversions
-78 00 01 00
Write STOP bit to Control Register, to terminate
auto-boot initialization sequence.
8.3 Which E2PROMs Can Be Used?
Several industry-standard serial E2PROMs that will suc-
cessfully run auto-boot with th e CS5 461A ar e listed be-
low:
• Atmel AT25010, AT25020 or AT25040
• National Semiconductor NM25C040M8 or NM25020M8
• Xicor X25040SI
These types of serial E2PROMs expect a specific 8-bit
command (00000011) in order to perform a memory
read. The CS5461A has been hardware programmed to
transmit this 8-bit command to the E2PROM at the be-
ginning of the auto-boot sequence.
CS5463 EEPROM
EOUT1
EOUT2
MODE
SCLK
SDI
SDO
CS
SCK
SO
SI
CS
Connector to Ca librator
VD+
5 K
5 K
Mech. Counter
Stepper Motor
or
Figure 17. Typical Interface of E2PROM to CS5463
CS5463
DS678F3 41
9. BASIC APPLICATION CIRCUITS
Figure 18 shows the CS5463 configured to measure
power in a singl e-pha se, 2- wire sys tem wh ile op erati ng
in a single-supply co nfiguration. In this diagram, a shunt
resistor is used to sense the line current and a voltage
divider is use d to sense the line voltage. In t his type of
shunt-resistor configur ation , the co mmon-m ode leve l of
the CS5463 must be referenced to the line side of the
power line. This means that the common-mode poten-
tial of the CS5463 will track the high-voltage levels, as
well as low-voltage levels, with respect to earth grou nd.
Isolation circuitry is required when an earth-ground-ref-
erenced communication interface is connected.
Figure 19 shows the same single-phase, two-wire sys-
tem with complete isolation from the power lines. This
isolation is achieved using three transformers: a general
purpose transformer to supply the on-board DC power;
a high-precision, low-impedance voltage transformer,
with very little roll-off/phase-delay, to measure voltage;
and a current transformer to sense the line current.
Figure 20 shows a single-phase, 3-wire system. In
many 3-wire residential power systems within the Unit-
ed States, only the two line terminals are available (neu-
tral is not available). Figure 21 shows the CS5463
configured to meter a thre e-wir e system with no ne utral
available.
VA+ VD+
CS5463
0.1 µF470 µF
500
470 nF
500
N
R1
R2
10
14
VIN+
9
VIN-
IIN-
10
15
16 IIN+
PFMON
CPUCLK
XOUT
XIN Optional
Clock
Source
Serial
Data
Interface
RESET
17
2
1
24
19
CS 7
SDI 23
SDO 6
SCLK 5
INT 20
E1
0.1 µF
VREFIN
12
VREFOUT
11
AGND DGND
13 4
3
4.096 MHz
0.1 µF
10 k
5k
L
RShunt
RV-
RI-
RI+
ISOLATION
120 VAC
Mech. Counter
Stepper Motor
or
22
21
CI-
CI+
CIdiff
CV-
CV+
CVdiff
E2
Note:
Indicates common (floating) return.
Figure 18. Typical Connection Diagram (Single-phase, 2-wire – Direct Connect to Power Line)
CS5463
42 DS678F3
VA+ VD+
CS5463
0.1 µF470 µF
500
470 nF
500
N
R3R4
RBurden
10
14
VIN+
9
VIN-
IIN-
10
16
15
IIN+
PFMON
CPUCLK
XOUT
XIN Optional
Clock
Source
RESET
17
2
1
24
CS
SD
SDO
SCLK
INT
0.1 µF
VREFIN
12
VREFOUT
11
DGND
13 4
3
4.095 MHz
0.1 µF
L1L2
10 k
5k
R1
R
2
RI+
RI-
22
21
Mech. Counte r
Stepper Motor
or
1k
1k
120 VAC 120 VAC
240 VAC
Serial
Data
Interface
19
7
23
6
5
20
I
Earth
Ground
CIdiff
CIdiff
E1
AGND
E2
Figure 20. Typical Connection Diagram (Single-phase, 3-wire)
Mech. Counter
Stepper Motor
or
VA+ VD+
CS5463
0.1µF
200µF
200
N10
14
VIN+
9
VIN-
IIN-
10
15
16 IIN+
PFMON
CPUCLK
XOUT
XIN Optional
Clock
Source
RESET
17
2
1
24
CS
SDI
SDO
SCLK
INT 22
E1 21
0.1 µF
VREFIN
12
VREFOUT
11
AGND DGND
13 4
3
4.096 MHz
0.1 µF
10 k
5k
L
M:1
R
N:1
Low Phase-Shift
Potential Transf or mer
Current
Transformer
RV+
RV-
CVdiff
RI-
RI+
C
Burden Idiff
Voltage
Transformer
120 VAC
12 VAC
12 VAC
200
Serial
Data
Interface
19
7
23
6
5
20
1k
1k
1k
1k
E2
Figure 19. Typical Connection Dia gram (Single-phase, 2-wire – Isolated from Power Line)
CS5463
DS678F3 43
VA+ VD+
0.1 µF470 µF
1k
235nF
500
R1R2
10
14
VIN+
9
VIN-
IIN-
10
16
15
IIN+
PFMON
CPUCLK
XOUT
XIN Optional
Clock
Source
RESET
17
2
1
24
CS
SDI
SDO
SCLK
INT
0.1 µF
VREFIN
12
VREFOUT
11
DGND
13 4
3
4.096 MHz
0.1 µF
L1L2
10 k
5k
RI+
RI-
RV-
Serial
Data
Interface
19
7
23
6
5
20
ISOLATION
22
21
Mech. Counter
Stepper Motor
or
RBurden
1k
1k
240 VAC
CS5463
Note:
Indicates common (floating) return.
CVdiff
CI+
CV+
CIdiff
E1
AGND
E2
Figure 21. Typical Connection Diagram (Single-phase, 3-wire – No Neutral Available)
CS5463
44 DS678F3
10.PACKAGE DIMENSIONS
Notes: 3. “D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold
mismatch and are measured at the parting li ne, mold flash or protrusions shall not exceed 0.20 mm per
side.
4. Dimension “b” does not include dambar protrusion/intrusion. Allowabl e dambar protrusion shall be
0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not
reduce dimension “b” by more than 0.07 mm at least material condition .
5. These dimensions apply to th e flat section of the lead between 0.10 and 0.25 mm from lead tips.
INCHES MILLIMETERS NOTE
DIM MIN NOM MAX MIN NOM MAX
A -- -- 0.084 -- -- 2.13
A1 0.002 0.006 0.010 0.05 0.13 0.25
A2 0.064 0.068 0.074 1.62 1.73 1.88
b 0.009 -- 0.015 0.22 -- 0.38 2,3
D 0.311 0.323 0.335 7.90 8.20 8.50 1
E 0.291 0.307 0.323 7.40 7.80 8.20
E1 0.197 0.209 0.220 5.00 5.30 5.60 1
e 0.022 0.026 0.030 0.55 0.65 0.75
L 0.025 0.03 0.041 0.63 0.75 1.03
0° 4° 8° 0° 4° 8°
JEDEC #: MO-150
Controlling Dimension is Millimeters.
E
N
123
eb2A1
A2 A
D
SEATING
PLANE
E1
1
L
SID E VI EW
END VIEW
TO P VIE W
24L SSOP PACKAGE DRAWING
CS5463
DS678F3 45
11. ORDERING INFORMATION
12. ENVIRONMENTAL, MANUFACTURING, & HANDLING INFORMATION
* MSL (Moisture Sensitivity Level) as specified by IPC/JEDEC J-STD-020.
Model Temperature Package
CS5463-ISZ (lead free) -40 to +85 °C 24-pin SSOP
Model Number Peak Reflow Temp MSL Rating* Max Floo r Life
CS5463-ISZ (lead free) 260 °C 3 7 Days
CS5463
46 DS678F3
13. REVISION HISTORY
Revision Date Changes
A1 MAR 2005 Advance Release
PP1 AUG 2005 First preliminary release.
F1 NOV 2005 First final release, updated with most-current characterization data.
F2 APR 2008 Added PulseWidth & LoadMin Registers.
F3 APR 2011 Removed lead-containing (Pb) device ordering information.
Contacting Cirrus Logic Support
For all product questions and inquiries contact a Cirrus Logic Sales Representative.
To find the one nearest to you go to www.cirrus.com
IMPORTANT NOTICE
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to change without notice and is pr ovided “AS IS” wi thout war ranty o f any ki nd (expre ss or impl ied). Customers are advi sed to ob tain the latest version of relevant
information to ve rify, before plac ing or ders, tha t inform ation b eing relied on is curren t and com plete. All pr oducts ar e sold subje ct to the term s and co nditio ns of sale
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copyrights, tradem arks, trade secrets or other intellectual pr operty rights. Cirrus owns the copyrights associated with the information contained herein a nd gives con-
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does not extend to othe r copying such as copyin g for ge ne ral distri bu tion , adve rtisi ng or p romotional purp oses, or for creating any w or k for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROP-
ERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE
IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRIT-
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Cirrus L ogic, Cirrus, and the Cirrus Log ic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this doc ument may be trademarks
or service marks of their respective owners.
SPI is a trademark of Motorola, Inc.
Microwire is a trademark of National Semiconductor Corporation.
