90E22PYGI8 - ATMEL - Product.Network

Single-Phase High-Performance

Wide-Span Energy Metering IC

90E21/22/23/24

Version 6

April 2, 2013

XXX

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Table of Contents 3 April 2, 2013

FEATURES.............................................................................................................................................................................. 6

APPLICATION......................................................................................................................................................................... 6

DESCRIPTION......................................................................................................................................................................... 6

BLOCK DIAGRAM .................................................................................................................................................................. 7

1 PIN ASSIGNMENT ............................................................................................................................................................. 9

2 PIN DESCRIPTION .......................................................................................................................................................... 10

3 FUNCTIONAL DESCRIPTION ......................................................................................................................................... 12

3.1 DYNAMIC METERING RANGE .................................................................................................................................................................... 12

3.2 STARTUP AND NO-LOAD POWER ............................................................................................................................................................. 12

3.3 ENERGY REGISTERS .................................................................................................................................................................................. 12

3.4 N LINE METERING AND ANTI-TAMPERING .............................................................................................................................................. 13

3.4.1 Metering Mode and L/N Line Current Sampling Gain Configuration ......................................................................................... 13

3.4.2 Anti-Tampering Mode .................................................................................................................................................................... 13

3.5 MEASUREMENT AND ZERO-CROSSING ................................................................................................................................................... 14

3.5.1 Measurement .................................................................................................................................................................................. 14

3.5.2 Zero-Crossing ................................................................................................................................................................................. 14

3.6 CALIBRATION .............................................................................................................................................................................................. 15

3.7 RESET ........................................................................................................................................................................................................... 15

4 INTERFACE ..................................................................................................................................................................... 16

4.1 SERIAL PERIPHERAL INTERFACE (SPI) ................................................................................................................................................... 16

4.1.1 Four-Wire Mode .............................................................................................................................................................................. 16

4.1.2 Three-Wire Mode ............................................................................................................................................................................ 17

4.1.3 Timeout and Protection ................................................................................................................................................................. 18

4.2 WARNOUT PIN FOR FATAL ERROR WARNING ....................................................................................................................................... 18

4.3 LOW COST IMPLEMENTATION IN ISOLATION WITH MCU ...................................................................................................................... 18

5 REGISTER ........................................................................................................................................................................ 19

5.1 REGISTER LIST ............................................................................................................................................................................................ 19

5.2 STATUS AND SPECIAL REGISTER ............................................................................................................................................................ 21

5.3 METERING/ MEASUREMENT CALIBRATION AND CONFIGURATION .................................................................................................... 25

5.3.1 Metering Calibration and Configuration Register ....................................................................................................................... 25

5.3.2 Measurement Calibration Register ............................................................................................................................................... 32

5.4 ENERGY REGISTER .................................................................................................................................................................................... 37

5.5 MEASUREMENT REGISTER ....................................................................................................................................................................... 41

6 ELECTRICAL SPECIFICATION ....................................................................................................................................... 48

6.1 ELECTRICAL SPECIFICATION ................................................................................................................................................................... 48

6.2 SPI INTERFACE TIMING .............................................................................................................................................................................. 50

6.3 POWER ON RESET TIMING ........................................................................................................................................................................ 51

6.4 ZERO-CROSSING TIMING ........................................................................................................................................................................... 51

6.5 VOLTAGE SAG TIMING ............................................................................................................................................................................... 52

6.6 PULSE OUTPUT ........................................................................................................................................................................................... 52

6.7 ABSOLUTE MAXIMUM RATING .................................................................................................................................................................. 53

PACKAGE DIMENSIONS...................................................................................................................................................... 54

ORDERING INFORMATION.................................................................................................................................................. 57

Table of Contents

List of Tables 4 April 2, 2013

Table-1 Function List ................................................................................................................................................................................................... 6

Table-2 Pin Description ............................................................................................................................................................................................. 10

Table-3 Active Energy Metering Error ....................................................................................................................................................................... 12

Table-4 Reactive Energy Metering Error ................................................................................................................................................................... 12

Table-5 Threshold Configuration for Startup and No-Load Power ............................................................................................................................ 12

Table-6 Energy Registers ......................................................................................................................................................................................... 12

Table-7 Metering Mode ............................................................................................................................................................................................. 13

Table-8 The Measurement Format ........................................................................................................................................................................... 14

Table-9 Read / Write Result in Four-Wire Mode ....................................................................................................................................................... 18

Table-10 Read / Write Result in Three-Wire Mode ..................................................................................................................................................... 18

Table-11 Register List ................................................................................................................................................................................................. 19

Table-12 SPI Timing Specification .............................................................................................................................................................................. 50

Table-13 Power On Reset Specification ..................................................................................................................................................................... 51

Table-14 Zero-Crossing Specification ......................................................................................................................................................................... 52

Table-15 Voltage Sag Specification ............................................................................................................................................................................ 52

List of Tables

List of Figures 5 April 2, 2013

Figure-1 90E21 Block Diagram .................................................................................................................................................................................... 7

Figure-2 90E22 Block Diagram .................................................................................................................................................................................... 7

Figure-3 90E23 Block Diagram .................................................................................................................................................................................... 8

Figure-4 90E24 Block Diagram .................................................................................................................................................................................... 8

Figure-5 Pin Assignment (Top View) ............................................................................................................................................................................ 9

Figure-6 Read Sequence in Four-Wire Mode ............................................................................................................................................................ 16

Figure-7 Write Sequence in Four-Wire Mode ............................................................................................................................................................. 16

Figure-8 Read Sequence in Three-Wire Mode .......................................................................................................................................................... 17

Figure-9 Write Sequence in Three-Wire Mode ........................................................................................................................................................... 17

Figure-10 4-Wire SPI Timing Diagram ......................................................................................................................................................................... 50

Figure-11 3-Wire SPI Timing Diagram ......................................................................................................................................................................... 50

Figure-12 Power On Reset Timing Diagram ................................................................................................................................................................ 51

Figure-13 Zero-Crossing Timing Diagram ................................................................................................................................................................... 51

Figure-14 Voltage Sag Timing Diagram ...................................................................................................................................................................... 52

Figure-15 Output Pulse Width ..................................................................................................................................................................................... 52

List of Figures

6 April 2, 2013

90E21/22/23/24

DSC-7277/6

Single-Phase High-Performance

Wide-Span Energy Metering IC

FEATURES

Metering Features

•Metering features fully in compliance with the requirements of

IEC62052-11, IEC62053-21 and IEC62053-23; applicable in

class 1 or class 2 single-phase watt-hour meter or class 2 single-

phase var-hour meter.

•Accuracy of 0.1% for active energy and 0.2% for reactive energy

over a dynamic range of 5000:1.

•Temperature coefficient is 15 ppm/ ℃ (typical) for on-chip refer-

ence voltage

•Single-point calibration over a dynamic range of 5000:1 for

active energy; no calibration needed for reactive energy.

•Energy Meter Constant doubling at low current to save verifica-

tion time.

•Electrical parameters measurement: less than ±0.5% fiducial

error for Vrms, Irms, mean active/ reactive/ apparent power, fre-

quency, power factor and phase angle.

•Forward/ reverse active/ reactive energy with independent

energy registers. Active/ reactive energy can be output by pulse

or read through energy registers to adapt to different applica-

tions.

•Programmable startup and no-load power threshold.

•Dedicated ADC and different gains for L line and N line current

sampling circuits. Current sampled over shunt resistor or current

transformer (CT); voltage sampled over resistor divider network

or potential transformer (PT).

•Programmable L line and N line metering modes: anti-tampering

mode (larger power), L line mode (fixed L line), L+N mode (appli-

cable for single-phase three-wire system) and flexible mode

(configure through register).

•Programmable L line and N line power difference threshold in

anti-tampering mode.

Other Features

•3.3V single power supply. Operating voltage range: 2.8~3.6V.

Metering accuracy guaranteed within 3.0V~3.6V. 5V compatible

for digital input.

•Built-in hysteresis for power-on reset.

•Four-wire SPI interface or simplified three-wire SPI interface with

fixed 24 cycles for all registers operation

•Parameter diagnosis function and programmable interrupt output

of the IRQ interrupt signal and the WarnOut signal.

•Programmable voltage sag detection and zero-crossing output.

•Channel input range

-Voltage channel (when gain is '1'): 120μVrms~600mVrms.

-L line current channel (when gain is '24'): 5μVrms~25mVrms.

-N line current channel (when gain is '1'): 120

Vrms~600mVrms.

•Programmable L line current gain: 1, 4, 8, 16, 24; Programmable

N line gain: 1, 2, 4.

•Support L line and N line offset compensation.

•CF1 and CF2 output active and reactive energy pulses respec-

tively which can be used for calibration or energy accumulation.

•Crystal oscillator frequency: 8.192 MHz. On-chip 10pF capaci-

tors and no need of external capacitors.

•Green SSOP28 package.

•Operating temperature: -40 ℃ ~ +85 ℃.

APPLICATION

•The 90E21/22/23/24 series are used for active and reactive

energy metering for single-phase two-wire, single-phase three-

wire or anti-tampering energy meters. With the measurement

function, the 90E21/22/23/24 series can also be used in power

instruments which need to measure voltage, current, etc.

DESCRIPTION

The 90E21/22/23/24 series are high-performance wide-span energy

metering chips. The ADC and DSP technology ensure the chips' long-

term stability over variations in grid and ambient environmental condi-

tions.

90E21/22/23/24 are all of green SSOP28 package with the same pin

alignment. In this datasheet, all reactive energy metering parts are only

applicable for the 90E22/24, and all N line metering and measurement

parts are only applicable for the 90E23/24.

Table-1 Function List

Part

Number

Active Energy

Metering

Reactive Energy

Metering

N Line

Metering

Electrical

Parameters

Measurement

90E21 √√

90E22 √√ √

90E23 √√√

90E24 √√√√

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Block Diagram 7 April 2, 2013

BLOCK DIAGRAM

Figure-1 90E21 Block Diagram

Figure-2 90E22 Block Diagram

Reference Voltage

Power On Reset

Crystal Oscillator 3-wire or 4-wire SPI

Vref

I1P

I1N

L Line Forward/Reverse Active Power

L Line Apparent Power

L Line Irms

Vrms

CS SCLK SDO SDI

OSCI OSCO

RESET

∑△ADC

HPF1 HPF0

DSP Module

PGA

X1/X4/X8/

X16/X24

PGA

Active Energy

Pulse Output

CF1

HPF1 HPF0

Power Factor/

Angle/Frequency

WarnOut/IRQ/ZX

IRQWarnOut

Reference Voltage

Power On Reset

Crystal Oscillator 3-wire or 4-wire SPI

Vref

I1P

I1N

L Line Forward/Reverse Active/

Reactive Power

L Line Apparent Power

L Line Irms

Vrms

CS SCLK SDO SDI

OSCI OSCO

RESET

∑△ADC

HPF1 HPF0

DSP Module

PGA

X1/X4/X8/

X16/X24

PGA

Active

Energy Pulse

Output

Reactive

Energy Pulse

Output

CF1 CF2

HPF1 HPF0

Power Factor/

Angle/Frequency

WarnOut/IRQ/ZX

IRQWarnOut

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Block Diagram 8 April 2, 2013

Figure-3 90E23 Block Diagram

Figure-4 90E24 Block Diagram

Reference Voltage

Power On Reset

Crystal Oscillator 3-wire or 4-wire SPI

Vref

I1P

I1N

L Line Forward/Reverse Active Power

L Line Apparent Power

L Line Irms

Vrms

I2P

I2N

MMD1 MMD0

CS SCLK SDO SDI

OSCI OSCO

RESET

∑△ADC

HPF1 HPF0

DSP Module

PGA

X1/X4/X8/

X16/X24

PGA

∑△ADC

PGA

X1/X2/X4

Active Energy

Pulse Output

CF1

HPF1 HPF0

N Line Forward/Reverse Active Power

N Line Apparent Power

N Line Irms

Power Factor/

Angle/Frequency

WarnOut/IRQ/ZX

IRQWarnOut

Reference Voltage

Power On Reset

Crystal Oscillator 3-wire or 4-wire SPI

Vref

I1P

I1N

L Line Forward/Reverse Active/

Reactive Power

L Line Apparent Power

L Line Irms

Vrms

I2P

I2N

MMD1 MMD0

CS SCLK SDO SDI

OSCI OSCO

RESET

∑△ADC

HPF1 HPF0

DSP Module

PGA

X1/X4/X8/

X16/X24

PGA

∑△ADC

PGA

X1/X2/X4

Active

Energy Pulse

Output

Reactive

Energy Pulse

Output

CF1 CF2

HPF1 HPF0

N Line Forward/Reverse Active/

Reactive Power

N Line Apparent Power

N Line Irms

Power Factor/

Angle/Frequency

WarnOut/IRQ/ZX

IRQWarnOut

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Pin Assignment 9 April 2, 2013

1 PIN ASSIGNMENT

Figure-5 Pin Assignment (Top View)

Note 1: Pin 1 and 28 are dedicated for the 90E23/24. Pin 1 should connect to DGND and pin 28 should connect to DVDD for 90E21/22.

Note 2: Pin 7 and 8 are dedicated for the 90E23/24. They should be left open for the 90E21/22.

Note 3: Pin 19 is dedicated for the 90E22/24. It should be left open for the 90E21/23.

1note 1

7note 2

8note 2

14 15

19note 3

28note 1

Reset

DVDD

AVDD

AGND

I1P

I1N

I2P

I2N

Vref

AGND

WarnOut

SCLK

SDO

SDIDGND

MMD1 MMD0

OSCI

OSCO

CF1

CF2

IRQ

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Pin Description 10 April 2, 2013

2 PIN DESCRIPTION

Table-2 Pin Description

Name Pin No. I/O

note 1

Type Description

Reset 4ILVTTL

Reset: Reset Pin (active low)

This pin should connect to ground through a 0.1μF filter capacitor. In application it can also

directly connect to one output pin from microcontroller (MCU).

DVDD 3 I Power

DVDD: Digital Power Supply

This pin provides power supply to the digital part. It should be decoupled with a 10μF electro-

lytic capacitor and a 0.1μF capacitor.

DGND 2 I Power DGND: Digital Ground

AVDD 5 I Power

AVDD: Analog Power Supply

This pin provides power supply to the analog part. This pin should connect to DVDD through

a 10Ω resistor and be decoupled with a 0.1μF capacitor.

Vref 13 O Analog Vref: Output Pin for Reference Voltage

This pin should be decoupled with a 1μF capacitor and a 1nF capacitor.

AGND 6, 14 I Power AGND: Analog Ground

I1P

I1N

11 I Analog

I1P: Positive Input for L Line Current

I1N: Negative Input for L Line Current

These pins are differential inputs for L line current. Input range is 5μVrms~25mVrms when

gain is '24'.

I2P

I2N

8I Analog

I2P: Positive Input for N Line Current

I2N: Negative Input for N Line Current

These pins are differential inputs for N line current. Input range is 120μVrms~600mVrms

when gain is '1'.

Note: I2P and I2N are dedicated for the 90E23/24. They should be left open for the 90E21/

22.

15 I Analog

VP: Positive Input for Voltage

VN: Negative Input for Voltage

These pins are differential inputs for voltage. Input range is 120μVrms~600mVrms.

NC 9, 12 NC: This pin should be left open.

CS 24 ILVTTL

CS: Chip Select (Active Low)

In 4-wire SPI mode, this pin must be driven from high to low for each read/write operation,

and maintain low for the entire operation. In 3-wire SPI mode, this pin must be low all the

time. Refer to section 4.1.

SCLK 25 ILVTTL

SCLK: Serial Clock

This pin is used as the clock for the SPI interface. Data on SDI is shifted into the chip on the

rising edge of SCLK while data on SDO is shifted out of the chip on the falling edge of SCLK.

SDO 26 OZ LVTTL

SDO: Serial Data Output

This pin is used as the data output for the SPI interface. Data on this pin is shifted out of the

chip on the falling edge of SCLK.

SDI 27 ILVTTL

SDI: Serial Data Input

This pin is used as the data input for the SPI interface. Address and data on this pin is shifted

into the chip on the rising edge of SCLK.

MMD1

MMD0

28 ILVTTL

MMD1/0: Metering Mode Configuration

00: anti-tampering mode (larger power);

01: L line mode (fixed L line);

10: L+N mode (applicable for single-phase three-wire system);

11: flexible mode (line specified by the LNSel bit (MMode, 2BH))

Note: The MMD1/0 pins are dedicated for the 90E23/24. For the 90E21/22, the metering

mode is fixed as L line mode, and MMD1 should connect to DGND and MMD0 should con-

nect to DVDD.

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Pin Description 11 April 2, 2013

OSCI 22 I LVTTL

OSCI: External Crystal Input

An 8.192 MHz crystal is connected between OSCI and OSCO. There is an on-chip 10pF

capacitor, therefore no need of external capacitors.

OSCO 23 O LVTTL

OSCO: External Crystal Output

An 8.192 MHz crystal is connected between OSCI and OSCO. There is an on-chip 10pF

capacitor, therefore no need of external capacitors.

CF1

CF2

19 O LVTTL

CF1: Active Energy Pulse Output

CF2: Reactive Energy Pulse Output

These pins output active/reactive energy pulses.

Note: CF2 is dedicated for the 90E22/24. It should be left open for the 90E21/23.

ZX 21 O LVTTL

ZX: Voltage Zero-Crossing Output

This pin is asserted when voltage crosses zero. Zero-crossing mode can be configured to

positive zero-crossing, negative zero-crossing or all zero-crossing by the Zxcon[1:0] bits

(MMode, 2BH).

IRQ 20 O LVTTL

IRQ: Interrupt Output

This pin is asserted when one or more events in the SysStatus register (01H) occur. It is

deasserted when there is no bit set in the SysStatus register (01H).

WarnOut 17 O LVTTL

WarnOut: Fatal Error Warning

This pin is asserted when there is metering parameter calibration error or voltage sag. Refer

to section 4.2.

Note 1: All digital inputs are 5V tolerant except for the OSCI pin.

Table-2 Pin Description (Continued)

Name Pin No. I/O

note 1

Type Description

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Functional Description 12 April 2, 2013

3 FUNCTIONAL DESCRIPTION

3.1 DYNAMIC METERING RANGE

Accuracy is 0.1% for active energy metering and 0.2% for reactive

energy metering over a dynamic range of 5000:1 (typical). Refer to

Table-3 and Table-4.

3.2 STARTUP AND NO-LOAD POWER

Startup and no-load power thresholds are programmable, both for

active and reactive power. The related registers are listed in Table-5.

The chip will start within 1.2 times of the theoretical startup time of

the configured startup power, if startup power is less than the corre-

sponding power of 20mA when power factor or sinφ is 1.0.

The chip has no-load status bits, the Pnoload/Qnoload bit (EnStatus,

46H). The chip will not output any active pulse (CF1) in active no-load

state. The chip will not output any reactive pulse (CF2) in reactive no-

load state.

3.3 ENERGY REGISTERS

The 90E21/22/23/24 provides energy pulse output CFx (CF1/CF2)

which is proportionate to active/reactive energy. Energy is usually accu-

mulated by adding the CFx pulses in system applications. Alternatively,

the 90E21/22/23/24 provides energy registers. There are forward

(inductive), reverse (capacitive) and absolute energy registers for both

active and reactive energy. Refer to Table-6.

Each energy register is cleared after read. The resolution of energy

registers is 0.1CF, i.e. one LSB represents 0.1 energy pulse.

Table-3 Active Energy Metering Error

Current Power Factor Error(%)

20mA ≤I＜50mA 1.0 ±0.2

50mA ≤I≤100A ±0.1

50mA ≤I＜100mA 0.5 (Inductive)

0.8 (Capacitive)

±0.2

100mA ≤I≤100A ±0.1

Note: Shunt resistor is 250 μΩ or CT ratio is 1000:1 and load resistor is 6Ω.

Table-4 Reactive Energy Metering Error

Current sinφ (Inductive or

Capacitive) Error(%)

20mA ≤I＜50mA 1.0 ±0.4

50mA ≤I≤100A ±0.2

50mA ≤I＜100mA 0.5 ±0.4

100mA ≤I≤100A ±0.2

Note: Shunt resistor is 250 μΩ or CT ratio is 1000:1 and load resistor is 6Ω.

Table-5 Threshold Configuration for Startup and No-Load Power

Threshold Register

Threshold for Active Startup Power PStartTh, 27H

Threshold for Active No-load Power PNolTh, 28H

Threshold for Reactive Startup Power QStartTh, 29H

Threshold for Reactive No-load Power QNolTh, 2AH

Table-6 Energy Registers

Energy Register

Forward Active Energy APenergy, 40H

Reverse Active Energy ANenergy, 41H

Absolute Active Energy ATenergy, 42H

Forward (Inductive) Reactive Energy RPenergy, 43H

Reverse (Capacitive) Reactive Energy RNenergy, 44H

Absolute Reactive Energy RTenergy, 45H

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Functional Description 13 April 2, 2013

3.4 N LINE METERING AND ANTI-TAMPERING

3.4.1 METERING MODE AND L/N LINE CURRENT SAMPLING

GAIN CONFIGURATION

The 90E23 and 90E24 have two current sampling circuits with N line

metering and anti-tampering functions. The MMD1 and MMD0 pins are

used to configure the metering mode. Refer to Table-7.

The 90E23 and 90E24 have two current sampling circuits with differ-

ent gain configurations. L line gain can be 1, 4, 8, 16 and 24, and N line

gain can be 1, 2 and 4. The configuration is made by the MMode register

(2BH). Generally L line can be sampled over shunt resistor or CT. N line

can be sampled over CT for isolation consideration. Note that Rogowski

coil is not supported.

3.4.2 ANTI-TAMPERING MODE

Threshold

In anti-tampering mode, the power difference threshold between L

line and N line can be: 1%, 2%,... 12%, 12.5%, 6.25%, 3.125% and

1.5625%, altogether 16 choices. The configuration is made by the

Pthresh[3:0] bits (MMode, 2BH) and the default value is 3.125%. The

threshold is applicable for active energy. The metering line of the reac-

tive energy follows that of the active energy.

Compare Method

In anti-tampering mode, the compare method is as follows:

If current metering line is L line and

N line is switched as the metering line, otherwise L line keeps as the

metering line.

If current metering line is N line and

L line is switched as the metering line, otherwise N line keeps as the

metering line.

This method can achieve hysteresis around the threshold automati-

cally. L line is employed after reset by default.

Special Treatment at Low Power

When power is low, general factors such as the quantization error or

calibration difference between L line and N line might cause the power

difference to be exceeded. To ensure L line and N line to start up nor-

mally, special treatment as follows is adopted:

The line with higher power is selected as the metering line when both

L line and N line power are lower than 8 times of the startup power but

higher than the startup power.

Table-7 Metering Mode

MMD1 MMD0 Metering Mode CFx (CF1 or CF2) Output

00Anti-tampering Mode

(larger power)

CFx represents the larger energy

line. Refer to section 3.4.2.

0 1 L Line Mode (fixed L line) CFx represents L line energy all

the time.

L+N Mode (applicable for

single-phase three-wire

system)

CFx represents the arithmetic

sum of L line and N line energy

Flexible Mode (line speci-

fied by the LNSel bit

(MMode, 2BH))

CFx represents energy of the

specified line.

Threshold100%*

Power ActiveLine L

Power ActiveLine L-Power ActiveLine N >

Threshold100%*

Power ActiveLine N

Power ActiveLine N-Power ActiveLine L >

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Functional Description 14 April 2, 2013

3.5 MEASUREMENT AND ZERO-CROSSING

3.5.1 MEASUREMENT

The 90E21/22/23/24 has the following measurements:

•voltage rms

•current rms (L line/N line)

•mean active power (L line/N line)

•mean reactive power (L line/N line)

•voltage frequency

•power factor (L line/N line)

•phase angle between voltage and current (L line/N line)

•mean apparent power (L line/N line)

The above measurements are all calculated with fiducial error except

for frequency. The frequency accuracy is 0.01Hz, and the other mea-

surement accuracy is 0.5%. Fiducial error is calculated as follow:

Where Umea is the measured voltage, Ureal is the actual voltage and

UFV is the fiducial value.

3.5.2 ZERO-CROSSING

The ZX pin is asserted when the sampling voltage crosses zero.

Zero-crossing mode can be configured to positive zero-crossing, nega-

tive zero-crossing and all zero-crossing by the Zxcon[1:0] bits (MMode,

2BH). Refer to section 6.4.

The zero-crossing signal can facilitate operations such as relay oper-

ation and power line carrier transmission in typical smart meter applica-

tions.

100%*

U-U

rrorFiducial_E

realmea

Table-8 The Measurement Format

Measurement Fiducial Value (FV) 90E21/22/23/24 Defined

Format Range Comment

Voltage rms Un XXX.XX 0~655.35V

Current rms

note 1, note 2

Imax

as 4Ib XX.XXX 0~65.535A

Active/ Reactive Power

note 1

maximum power as

Un*4Ib XX.XXX -32.768~+32.767

kW/kvar Complement, MSB as the sign bit

Apparent Power

note 1

Un*4Ib XX.XXX 0~+32.767 kVA Complement, MSB always '0'

Frequency fn XX.XX 45.00~65.00 Hz

Power Factor

note 3

1.000 X.XXX -1.000~+1.000 Signed, MSB as the sign bit

Phase Angle

note 4

180° XXX.X -180°~+180° Signed, MSB as the sign bit

Note 1: All registers are of 16 bits. For cases when the current and active/reactive/apparent power goes beyond the above range, it is suggested to be handled by

microcontroller (MCU) in application. For example, register value can be calibrated to 1/2 of the actual value during calibration, then multiply 2 in application. Note that

if the actual current is twice of that of the 90E21/22/23/24, the actual active/reactive/apparent power is also twice of that of the chip.

Note 2: The accuracy is not guaranteed when the current is lower than 15mA. Note that the tolerance is 25 mA at IFV of 5A and fiducial accuracy of 0.5%.

Note 3: Power factor is obtained by active power dividing apparent power

Note 4: Phase angle is obtained when voltage/current crosses zero at the frequency of 256kHz. Precision is not guaranteed at small current.

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Functional Description 15 April 2, 2013

3.6 CALIBRATION

Metering Calibration

Only single-point calibration is needed over the entire dynamic

range.

Metering calibration is realized by first calibrating gain at unity power

factor and then calibrating phase angle compensation at 0.5 inductive

power factor.

However, due to very small signal in L line current sampling circuits,

any external interference, e.g., a tens of nano volts influence voltage on

shunt resistor conducted by transformer in the energy meter’s power

supply may cause perceptible metering error, especially in low current

state. For this nearly constant external interference, the 90E21/22/23/24

also provides power offset compensation.

L line and N line need to be calibrated sequentially. Reactive does

not need to be calibrated.

Measurement Calibration

Measurement calibration is realized by calibrating the gains for volt-

age rms and current rms. Considering the possible nonlinearity around

zero caused by external components, the chip also provides offset com-

pensation for voltage rms, current rms, mean active power and mean

reactive power.

Frequency, phase angle and power factor do not need calibration.

For more calibration details, please refer to Application Note AN-641.

3.7 RESET

The 90E21/22/23/24 has an on-chip power supply monitor circuit with

built-in hysteresis. The 90E21/22/23/24 only works within the voltage

range.

The 90E21/22/23/24 has three means of reset: power-on reset, hard-

ware reset and software reset. All registers resume to their default value

after reset.

Power-on Reset: Power-on reset is initiated during power-up. Refer

to section 6.3.

Hardware Reset: Hardware Reset is initiated when the reset pin is

pulled low. The width of the reset signal should be over 200μs.

Software Reset: Software Reset is initiated when ‘789AH’ is written

to the software reset register (SoftReset, 00H).

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Interface 16 April 2, 2013

4INTERFACE

4.1 SERIAL PERIPHERAL INTERFACE (SPI)

SPI is a full-duplex, synchronous channel. There are two SPI modes:

four-wire mode and three-wire mode. In four-wire mode, four pins are

used: CS, SCLK, SDI and SDO. In three-wire mode, three pins are

used: SCLK, SDI and SDO. Data on SDI is shifted into the chip on the

rising edge of SCLK while data on SDO is shifted out of the chip on the

falling edge of SCLK. The LastSPIData register (06H) stores the 16-bit

data that is just read or written.

4.1.1 FOUR-WIRE MODE

In four-wire mode, the CS pin must be driven low for the entire read

or write operation. The first bit on SDI defines the access type and the

lower 7-bit is decoded as address.

Read Sequence

As shown in Figure-6, a read operation is initiated by a high on SDI

followed by a 7-bit register address. A 16-bit data in this register is then

shifted out of the chip on SDO. A complete read operation contains 24

cycles.

Figure-6 Read Sequence in Four-Wire Mode

Write Sequence

As shown in Figure-7, a write operation is initiated by a low on SDI

followed by a 7-bit register address. A 16-bit data is then shifted into the

chip on SDI. A complete write operation contains 24 cycles.

Figure-7 Write Sequence in Four-Wire Mode

SCLK

SDI

SDO

10123456789 111213141516171819202122 24

A0A6 A5 A4 A3 A2 A1

High Impedance D15

Don't care

16-bit data

D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1

SCLK

SDI

SDO

10123456789 11121314151617181920212223

A0A6 A5 A4 A3 A2 A1

16-bit data

High Impedance

D0D7 D6 D5 D4 D3 D2 D1

D15

D14D13D12D11D10 D9 D8

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Interface 17 April 2, 2013

4.1.2 THREE-WIRE MODE

In three-wire mode, CS is always at low level. When there is no oper-

ation, SCLK keeps at high level. The start of a read or write operation is

triggered if SCLK is consistently low for at least 400μs. The subsequent

read or write operation is similar to that in four-wire mode. Refer to Fig-

ure-8 and Figure-9.

Figure-8 Read Sequence in Three-Wire Mode

Figure-9 Write Sequence in Three-Wire Mode

SCLK

10123456789 11121314151617181920212223

24 1234

Low ≥400μs

Drive Low

SDI

SDO

A0A6 A5 A4 A3 A2 A1

Hign Impedance D

Don't care

16-bit data

Don’t care A6 A5 A4

High Impedance

Low ≥400μs

SCLK

SDI

SDO

10123456789 11121314151617181920212223

A0A6 A5 A4 A3 A2 A1

16-bit data

High Impedance

1234

A6 A5 A4Don't care

Drive low

Low ≥400μsLow ≥400μs

Don't care

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Interface 18 April 2, 2013

4.1.3 TIMEOUT AND PROTECTION

Timeout occurs if SCLK does not toggle for 6ms in both four-wire and

three-wire modes. When timeout, the read or write operation is aborted.

If there are more than 24 SCLK cycles when CS is driven low in four-

wire mode or between two starts in three-wire mode, writing operation is

prohibited while normal reading operation can be completed by taking

the first 24 SCLK cycles as the valid ones. However, the reading result

might not be the intended one.

A read access to an invalid address returns all zero. A write access

to an invalid address is discarded.

Table-9 and Table-10 list the read or write result in different condi-

tions.

4.2 WARNOUT PIN FOR FATAL ERROR WARNING

Fatal error warning is raised through the WarnOut pin in two cases:

checksum calibration error and voltage sag.

Calibration Error

The 90E21/22/23/24 performs diagnosis on a regular basis for impor-

tant parameters such as calibration parameters and metering configura-

tion. When checksum is not correct, the CalErr[1:0] bits (SysStatus,

01H) are set, and both the WarnOut pin and the IRQ pin are asserted.

When checksum is not correct, the metering part does not work to pre-

vent a large number of pulses during power-on or any abnormal situa-

tion upon incorrect parameters.

Voltage Sag

Voltage sag is detected when voltage is continuously below the volt-

age sag threshold for one cycle which starts from any zero-crossing

point. Voltage threshold is configured by the SagTh register (03H). Refer

to section 6.5.

When voltage sag occurs, the SagWarn bit (SysStatus, 01H) is set

and the WarnOut pin is asserted if the FuncEn register (02H) enables

voltage sag warning through the WarnOut pin. This function helps

reduce power-down detection circuit in system design. In addition, the

method of judging voltage sag by detecting AC side voltage eliminates

the influence of large capacitor in traditional rectifier circuit, and can

detect voltage sag earlier.

4.3 LOW COST IMPLEMENTATION IN ISOLATION

WITH MCU

The following functions can be achieved at low cost when the 90E21/

22/23/24 is isolated from the MCU:

SPI: MCU can perform read and write operations through low speed

optocoupler (e.g. NEC2501) when the 90E21/22/23/24 is isolated from

the MCU. The SPI interface can be of 3-wire or 4-wire.

Energy Pulses CFx: Energy can be accumulated by reading values

in corresponding energy registers. CFx can also connect to the optocou-

pler and the energy pulse light can be turned on by CFx.

Fatal Error WarnOut: Fatal error can be acquired by reading the CalE

rr[1:0] bits (SysStatus, 01H).

IRQ: IRQ interrupt can be acquired by reading the SysStatus register

(01H).

Reset: The 90E21/22/23/24 is reset when ‘789AH’ is written to the

software reset register (SoftReset, 00H).

Table-9 Read / Write Result in Four-Wire Mode

Condition Result

Operation Timeout SCLK Cycles

note 1

Read/Write

Status

LastSPIData

Read

note 2

>=24 Normal Read Yes

note 2

<24 Partial Read No

Write

No =24 Normal Write Yes

No !=24 No Write No

Yes - No Write No

Note 1: The number of SCLK cycles when CS is driven low or the number of

SCLK cycles before timeout if any.

Note 2: '-' stands for Don't Care.

Table-10 Read / Write Result in Three-Wire Mode

Condition Result

Operation Timeout SCLK Cycles

note 1

Read/Write

Status

LastSPIData

Read

No >=24

note 2

Normal Read Yes

Timeout after

24 cycles >24 Normal Read Yes

Timeout

before 24

cycles -

note 3

Partial Read No

Timeout at 24

cycles =24 Normal Read Yes

Write

No =24 Normal Write Yes

No !=24 No Write No

Yes - No Write No

Note 1: The number of SCLK cycles between 2 starts or the number of SCLK

cycles before timeout if any.

Note 2: There is no such case of less than 24 SCLK cycles when there is no

timeout in three-wire mode, because the first few SCLK cycles in the next oper-

ation is counted into this operation. In this case, data is corrupted.

Note 3: '-' stands for Don't Care.

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5 REGISTER

5.1 REGISTER LIST

Table-11 Register List

Address Register Name

Read/Write

Type Functional Description Comment

note 1

Page

Status and Special Register

00H SoftReset W Software Reset P21

01H SysStatus R/C System Status different for various chips

note 2, note 3

P22

02H FuncEn R/W Function Enable different for various chips

note 2

P23

03H SagTh R/W Voltage Sag Threshold P23

04H SmallPMod R/W Small-Power Mode P24

06H LastSPIData R Last Read/Write SPI Value P24

Metering Calibration and Configuration Register

20H CalStart R/W Calibration Start Command P25

21H PLconstH R/W High Word of PL_Constant P25

22H PLconstL R/W Low Word of PL_Constant P26

23H Lgain R/W L Line Calibration Gain P26

24H Lphi R/W L Line Calibration Angle P26

25H Ngain R/W N Line Calibration Gain Not applicable to the 90E21/22

note 3

P27

26H Nphi R/W N Line Calibration Angle Not applicable to the 90E21/22

note 3

P27

27H PStartTh R/W Active Startup Power Threshold P27

28H PNolTh R/W Active No-Load Power Threshold P28

29H QStartTh R/W Reactive Startup Power Threshold Not applicable to the 90E21/23

note 2

P28

2AH QNolTh R/W Reactive No-Load Power Threshold Not applicable to the 90E21/23

note 2

P28

2BH MMode R/W Metering Mode Configuration different for various chips

note 2, note 3

P29

2CH CS1 R/W Checksum 1 P31

Measurement Calibration Register

30H AdjStart R/W Measurement Calibration Start Command P32

31H Ugain R/W Voltage rms Gain P32

32H IgainL R/W L Line Current rms Gain P33

33H IgainN R/W N Line Current rms Gain Not applicable to the 90E21/22

note 3

P33

34H Uoffset R/W Voltage Offset P33

35H IoffsetL R/W L Line Current Offset P34

36H IoffsetN R/W N Line Current Offset Not applicable to the 90E21/22

note 3

P34

37H PoffsetL R/W L Line Active Power Offset P34

38H QoffsetL R/W L Line Reactive Power Offset Not applicable to the 90E21/23

note 2

P35

39H PoffsetN R/W N Line Active Power Offset Not applicable to the 90E21/22

note 3

P35

3AH QoffsetN R/W N Line Reactive Power Offset Not applicable to the 90E21/22/23

note 2, note 3

P35

3BH CS2 R/W Checksum 2 P36

Energy Register

40H APenergy R/C Forward Active Energy P37

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

41H ANenergy R/C Reverse Active Energy P37

42H ATenergy R/C Absolute Active Energy P38

43H RPenergy R/C Forward (Inductive) Reactive Energy Not applicable to the 90E21/23

note 2

P38

44H RNenergy R/C Reverse (Capacitive) Reactive Energy Not applicable to the 90E21/23

note 2

P39

45H RTenergy R/C Absolute Reactive Energy Not applicable to the 90E21/23

note 2

P39

46H EnStatus R Metering Status different for various chips

note 2, note 3

P40

Measurement Register

48H Irms R L Line Current rms P41

49H Urms R Voltage rms P41

4AH Pmean R L Line Mean Active Power P42

4BH Qmean R L Line Mean Reactive Power Not applicable to the 90E21/23

note 2

P42

4CH Freq R Voltage Frequency P43

4DH PowerF R L Line Power Factor P43

4EH Pangle R

Phase Angle between Voltage and L Line

Current P43

4FH Smean R L Line Mean Apparent Power P44

68H Irms2 R N Line Current rms Not applicable to the 90E21/22

note 3

P44

6AH Pmean2 R N Line Mean Active Power Not applicable to the 90E21/22

note 3

P45

6BH Qmean2 R N Line Mean Reactive Power Not applicable to the 90E21/22/23

note 2, note 3

P45

6DH PowerF2 R N Line Power Factor Not applicable to the 90E21/22

note 3

P46

6EH Pangle2 R

Phase Angle between Voltage and N Line

Current Not applicable to the 90E21/22

note 3

P46

6FH Smean2 R N Line Mean Apparent Power Not applicable to the 90E21/22

note 3

P47

Note:

1. This register list shows all registers for the 90E24.

2. This register is related to reactive energy metering. Part of this register is invalid for the 90E21/23 which does not have reactive metering. Reading these registers

always return 0000H and writing these registers always take no effect.

3. This register is related to N line metering. Part of this register is invalid for the 90E21/22 which does not have N line metering. Reading these registers always return

0000H and writing these registers always have no effect.

Table-11 Register List (Continued)

Address Register Name

Read/Write

Type Functional Description Comment

note 1

Page

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5.2 STATUS AND SPECIAL REGISTER

SoftReset

Software Reset

Address: 00H

Type: Write

Default Value: 0000H

Bit Name Description

15 - 0 SoftReset[15:0] Software reset register. The 90E21/22/23/24 resets if only 789AH is written to this register.

15 14 13 12 11 10 9 8

SoftReset15 SoftReset14 SoftReset13 SoftReset12 SoftReset11 SoftReset10 SoftReset9 SoftReset8

76543210

SoftReset7 SoftReset6 SoftReset5 SoftReset4 SoftReset3 SoftReset2 SoftReset1 SoftReset0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

SysStatus

System Status

Address: 01H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 14 CalErr[1:0]

These bits indicate CS1 checksum status.

00: CS1 checksum correct (default)

11: CS1 checksum error. At the same time, the WarnOut pin is asserted.

13 - 12 AdjErr[1:0]

These bits indicate CS2 checksum status.

00: CS2 checksum correct (default)

11: CS2 checksum error.

11 - 8 - Reserved.

7 LNchange

This bit indicates whether there is any change of the metering line (L line and N line).

0: metering line no change (default)

1: metering line changed

6RevQchq

This bit indicates whether there is any change with the direction of reactive energy.

0: direction of reactive energy no change (default)

1: direction of reactive energy changed

This status is enabled by the RevQEn bit(FuncEn, 02H).

5 RevPchg

This bit indicates whether there is any change with the direction of active energy.

0: direction of active energy no change (default)

1: direction of active energy changed

This status is enabled by the RevPEn bit (FuncEn, 02H).

4 - 2 - Reserved.

1 SagWarn

This bit indicates the voltage sag status.

0: no voltage sag (default)

1: voltage sag

Voltage sag is enabled by the SagEn bit (FuncEn, 02H).

Voltage sag status can also be reported by the WarnOut pin. It is enabled by the SagWo bit(FuncEn, 02H).

Reserved.

Note: Any of the above events will prompt the IRQ pin to be asserted, which can be supplied to external MCU as an interrupt.

15 14 13 12 11 10 9 8

CalErr1 CalErr0 AdjErr1 AdjErr0 - - - -

76543210

LNchange RevQchg RevPchg - - - SagWarn -

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

FuncEn

Function Enable

SagTh

Voltage Sag Threshold

Address: 02H

Type: Read/Write

Default Value: 000CH

Bit Name Description

15 - 6 - Reserved.

5SagEn

This bit determines whether to enable the voltage sag interrupt.

0: disable (default)

1: enable

4SagWo

This bit determines whether to enable voltage sag to be reported by the WarnOut pin.

0: disable (default)

1: enable

3RevQEn

This bit determines whether to enable the direction change interrupt of reactive energy.

0: disable

1: enable (default)

2 RevPEn

This bit determines whether to enable the direction change interrupt of active energy.

0: disable

1: enable (default)

1 - 0 - Reserved.

Address: 03H

Type: Read/Write

Default Value: 1D6AH

Bit Name Description

15 - 0 SagTh[15:0]

Voltage sag threshold configuration. Data format is XXX.XX. Unit is V.

The power-on value of SagTh is 1D6AH, which is calculated by 22000*sqrt(2)*0.78/(4*Ugain/32768)

For details, please refer to application note AN-641.

15 14 13 12 11 10 9 8

--------

76543210

- - SagEn SagWo RevQEn RevPEn - -

15 14 13 12 11 10 9 8

SagTh15 SagTh14 SagTh13 SagTh12 SagTh11 SagTh10 SagTh9 SagTh8

76543210

SagTh7 SagTh6 SagTh5 SagTh4 SagTh3 SagTh2 SagTh1 SagTh0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

SmallPMod

Small-Power Mode

LastSPIData

Last Read/Write SPI Value

Address: 04H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 SmallPMod[15:0]

Small-power mode command.

A987H: small-power mode. The relationship between the register value of L line and N line active/reactive power in small-power

mode and normal mode is:

power in normal mode = power in small-power mode *10*Igain*Ugain /2^42

Others: Normal mode.

Small-power mode is mainly used in the power offset calibration.

Address: 06H

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 LastSPI-

Data[15:0] This register stores the data that is just read or written through the SPI interface. Refer to Table-9 and Table-10.

15 14 13 12 11 10 9 8

SmallPMod15 SmallPMod14 SmallPMod13 SmallPMod12 SmallPMod11 SmallPMod10 SmallPMod9 SmallPMod8

76543210

SmallPMod7 SmallPMod6 SmallPMod5 SmallPMod4 SmallPMod3 SmallPMod2 SmallPMod1 SmallPMod0

15 14 13 12 11 10 9 8

LastSPIData15 LastSPIData14 LastSPIData13 LastSPIData12 LastSPIData11 LastSPIData10 LastSPIData9 LastSPIData8

76543210

LastSPIData7 LastSPIData6 LastSPIData5 LastSPIData4 LastSPIData3 LastSPIData2 LastSPIData1 LastSPIData0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5.3 METERING/ MEASUREMENT CALIBRATION AND CONFIGURATION

5.3.1 METERING CALIBRATION AND CONFIGURATION REGISTER

CalStart

Calibration Start Command

PLconstH

High Word of PL_Constant

Address: 20H

Type: Read/Write

Default Value: 6886H

Bit Name Description

15 - 0 CalStart[15:0]

Metering calibration start command:

6886H: Power-on value. Metering function is disabled.

5678H: Metering calibration startup command. After 5678H is written to this register, registers 21H-2BH resume to their power-

on values. The 90E21/22/23/24 starts to meter and output energy pulses regardless of the correctness of diagnosis. The

CalErr[1:0] bits (SysStatus, 01H) are not set and the WarnOut/IRQ pins do not report any warning/interrupt.

8765H: Check the correctness of the 21H-2BH registers. If correct, normal metering. If not correct, metering function is disabled,

the CalErr[1:0] bits (SysStatus, 01H) are set and the WarnOut/IRQ pins report warning/interrupt.

Others: Metering function is disabled. The CalErr[1:0] bits (SysStatus, 01H) are set and the WarnOut/IRQ pins report warning/

interrupt.

Address: 21H

Type: Read/Write

Default Value: 0015H

Bit Name Description

15 - 0 PLconstH[15:0]

The PLconstH[15:0] and PLconstL[15:0] bits are high word and low word of PL_Constant respectively.

PL_Constant is a constant which is proportional to the sampling ratios of voltage and current, and inversely proportional to the

Meter Constant. PL_Constant is a threshold for energy calculated inside the chip, i.e., energy larger than PL_Constant will be

accumulated in the corresponding energy registers and then output on CFx.

It is suggested to set PL_constant as a multiple of 4 so as to double or redouble Meter Constant in low current state to save ver-

ification time.

Note: PLconstH takes effect after PLconstL are configured.

For details, please refer to application note AN-641.

15 14 13 12 11 10 9 8

CalStart15 CalStart14 CalStart13 CalStart12 CalStart11 CalStart10 CalStart9 CalStart8

76543210

CalStart7 CalStart6 CalStart5 CalStart4 CalStart3 CalStart2 CalStart1 CalStart0

15 14 13 12 11 10 9 8

PLconstH15 PLconstH14 PLconstH13 PLconstH12 PLconstH11 PLconstH10 PLconstH9 PLconstH8

76543210

PLconstH7 PLconstH6 PLconstH5 PLconstH4 PLconstH3 PLconstH2 PLconstH1 PLconstH0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

PLconstL

Low Word of PL_Constant

Lgain

L Line Calibration Gain

Lphi

L Line Calibration Angle

Address: 22H

Type: Read/Write

Default Value: D174H

Bit Name Description

15 - 0 PLconstL[15:0] The PLconstH[15:0] and PLconstL[15:0] bits are high word and low word of PL_Constant respectively.

It is suggested to set PL_constant as a multiple of 4. For details, please refer to application note AN-641.

Address: 23H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 Lgain[15:0] L line calibration gain. For details, please refer to application note AN-641.

Address: 24H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 Lphi[15:0] L line calibration phase angle. For details, please refer to application note AN-641.

15 14 13 12 11 10 9 8

PLconstL15 PLconstL14 PLconstL13 PLconstL12 PLconstL11 PLconstL10 PLconstL9 PLconstL8

76543210

PLconstL7 PLconstL6 PLconstL5 PLconstL4 PLconstL3 PLconstL2 PLconstL1 PLconstL0

15 14 13 12 11 10 9 8

Lgain15 Lgain14 Lgain13 Lgain12 Lgain11 Lgain10 Lgain9 Lgain8

76543210

Lgain7 Lgain6 Lgain5 Lgain4 Lgain3 Lgain2 Lgain1 Lgain0

15 14 13 12 11 10 9 8

Lphi15 - - - - - Lphi9 Lphi8

76543210

Lphi7 Lphi6 Lphi5 Lphi4 Lphi3 Lphi2 Lphi1 Lphi0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Ngain

N Line Calibration Gain

Nphi

N Line Calibration Angle

PStartTh

Active Startup Power Threshold

Address: 25H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 Ngain[15:0] N line calibration gain. For details, please refer to application note AN-641.

Address: 26H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 Nphi[15:0] N line calibration phase angle. For details, please refer to application note AN-641.

Address: 27H

Type: Read/Write

Default Value: 08BDH

Bit Name Description

15 - 0 PStartTh[15:0] Active startup power threshold. For details, please refer to application note AN-641.

15 14 13 12 11 10 9 8

Ngain15 Ngain14 Ngain13 Ngain12 Ngain11 Ngain10 Ngain9 Ngain8

76543210

Ngain7 Ngain6 Ngain5 Ngain4 Ngain3 Ngain2 Ngain1 Ngain0

15 14 13 12 11 10 9 8

Nphi15 - - - - - Nphi9 Nphi8

76543210

Nphi7 Nphi6 Nphi5 Nphi4 Nphi3 Nphi2 Nphi1 Nphi0

15 14 13 12 11 10 9 8

PStartTh15 PStartTh14 PStartTh13 PStartTh12 PStartTh11 PStartTh10 PStartTh9 PStartTh8

76543210

PStartTh7 PStartTh6 PStartTh5 PStartTh4 PStartTh3 PStartTh2 PStartTh1 PStartTh0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

PNolTh

Active No-Load Power Threshold

QStartTh

Reactive Startup Power Threshold

QNolTh

Reactive No-Load Power Threshold

Address: 28H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 PNolTh[15:0] Active no-load power threshold. For details, please refer to application note AN-641.

Address: 29H

Type: Read/Write

Default Value: 0AECH

Bit Name Description

15 - 0 QStartTh[15:0] Reactive startup power threshold. For details, please refer to application note AN-641.

Address: 2AH

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 QNolTh[15:0] Reactive no-load power threshold. For details, please refer to application note AN-641.

15 14 13 12 11 10 9 8

PNolTh15 PNolTh14 PNolTh13 PNolTh12 PNolTh11 PNolTh10 PNolTh9 PNolTh8

76543210

PNolTh7 PNolTh6 PNolTh5 PNolTh4 PNolTh3 PNolTh2 PNolTh1 PNolTh0

15 14 13 12 11 10 9 8

QStartTh15 QStartTh14 QStartTh13 QStartTh12 QStartTh11 QStartTh10 QStartTh9 QStartTh8

76543210

QStartTh7 QStartTh6 QStartTh5 QStartTh4 QStartTh3 QStartTh2 QStartTh1 QStartTh0

15 14 13 12 11 10 9 8

QNolTh15 QNolTh14 QNolTh13 QNolTh12 QNolTh11 QNolTh10 QNolTh9 QNolTh8

76543210

QNolTh7 QNolTh6 QNolTh5 QNolTh4 QNolTh3 QNolTh2 QNolTh1 QNolTh0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

MMode

Metering Mode Configuration

Address: 2BH

Type: Read/Write

Default Value: 9422H

Bit Name Description

15 - 13 Lgain[2:0]

L line current gain, default value is ‘100’.

12 - 11 Ngain[1:0]

N line current gain

00: 2

01: 4

10: 1 (default)

11: 1

10 LNSel

This bit specifies metering as L line or N line when metering mode is set to flexible mode by MMD1 and MMD0 pins.

0: N line

1: L line (default)

9 - 8 DisHPF[1:0]

These bits configure the High Filter Pass (HPF) after ADC. There are two first-order HPF in serial: HPF1 and HPF0. The config-

uration are applicable to all channels:

7Amod

CF1 output for active power:

0: forward or reverse energy pulse output (default)

1: absolute energy pulse output

6Rmod

CF2 output for reactive power:

0: forward (inductive) or reverse (capacitive) energy pulse output (default)

1: absolute energy pulse output

15 14 13 12 11 10 9 8

Lgain2 Lgain1 Lgain0 Ngain1 Ngain0 LNSel DisHPF1 DisHPF0

76543210

Amod Rmod ZXCon1 ZXCon0 Pthresh3 Pthresh2 Pthresh1 Pthresh0

Lgain2 Lgain1 Lgain0 Current Channel Gain

1XX 1

000 4

001 8

010 16

011 24

DisHPF1 DisHPF 0 HPF Configuration

0 0 enable HPF1 and HPF0 (default)

0 1 enable HPF1, disable HPF0;

1 0 disable HPF1, enable HPF0;

1 1 disable HPF1 and HPF0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5 - 4 Zxcon[1:0]

These bits configure zero-crossing mode. The ZX pin outputs 5ms-width high level when voltage crosses zero.

00: positive zero-crossing

01: negative zero-crossing

10: all zero-crossing: both positive and negative zero-crossing (default)

11: no zero-crossing output

3 - 0 Pthresh[3:0]

These bits configure the L line and N line power difference threshold in anti-tampering mode.

Pthresh3 Pthresh2 Pthresh1 Pthresh0 Threshold

0000 12.5%

0 0 0 1 6.25%

0 0 1 0 3.125% (default)

0 0 1 1 1.5625%

0100 1%

0101 2%

0110 3%

0111 4%

1000 5%

1001 6%

1010 7%

1011 8%

1100 9%

1 1 0 1 10%

1110 11%

1 1 1 1 12%

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

CS1

Checksum 1

Address: 2CH

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 CS1[15:0]

The CS1 register should be written after the 21H-2BH registers are written. Suppose the high byte and the low byte of the 21H-

2BH registers are shown in below table.

The calculatiion of the CS1 register is as follows:

The low byte of 2CH register is: L2C=MOD(H21+H22+...+H2B+L21+L22+...+L2B, 2^8)

The high byte of 2CH register is: H2C=H21 XOR H22 XOR ... XOR H2B XOR L21 XOR L22 XOR ... XOR L2B

For 90E21/22/23, a part of registers are not used. These registers can be dealed as 0000H in CS calculation.

The 90E21/22/23/24 calculates CS1 regularly. If the value of the CS1 register and the calculation by the 90E21/22/23/24 is differ-

ent when CalStart=8765H, the CalErr[1:0] bits (SysStatus, 01H) are set and the WarnOut and IRQ pins are asserted.

Note: The readout value of the CS1 register is the calculation by the 90E21/22/23/24, which is different from what is written.

15 14 13 12 11 10 9 8

CS1_15 CS1_14 CS1_13 CS1_12 CS1_11 CS1_10 CS1_9 CS1_8

76543210

CS1_7 CS1_6 CS1_5 CS1_4 CS1_3 CS1_2 CS1_1 CS1_0

21H H21 L21

22H H22 L22

23H H23 L23

24H H24 L24

25H H25 L25

26H H26 L26

27H H27 L27

28H H28 L28

29H H29 L29

2AH H2A L2A

2BH H2B L2B

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5.3.2 MEASUREMENT CALIBRATION REGISTER

AdjStart

Measurement Calibration Start Command

Ugain

Voltage rms Gain

Address: 30H

Type: Read/Write

Default Value: 6886H

Bit Name Description

15 - 0 AdjStart[15:0]

Measurement Calibration Start Command

6886H: Power-on value. No measurement.

5678H: Measurement calibration startup command. After 5678H is written to this register, registers 31H-3AH resume to their

power-on values. The 90E21/22/23/24 starts to measure regardless of the correctness of diagnosis. The AdjErr[1:0] bits

(SysStatus, 01H) are not set and the IRQ pin does not report any interrupt.

8765H: Check the correctness of the 31H-3AH registers. If correct, normal measurement. If not correct, measurement function is

disabled, the AdjErr[1:0] bits (SysStatus, 01H) are set and the IRQ pin reports interrupt.

Others: No measurement. The AdjErr[1:0] bits (SysStatus, 01H) are set and the IRQ pin reports interrupt.

Address: 31H

Type: Read/Write

Default Value: 6720H

Bit Name Description

15 - 0 Ugain[15:0] Voltage rms Gain. For details, please refer to application note AN-641.

Note: the Ugain15 bit should only be '0'

15 14 13 12 11 10 9 8

AdjStart15 AdjStart14 AdjStart13 AdjStart12 AdjStart11 AdjStart10 AdjStart9 AdjStart8

76543210

AdjStart7 AdjStart6 AdjStart5 AdjStart4 AdjStart3 AdjStart2 AdjStart1 AdjStart0

15 14 13 12 11 10 9 8

Ugain15 Ugain14 Ugain13 Ugain12 Ugain11 Ugain10 Ugain9 Ugain8

76543210

Ugain7 Ugain6 Ugain5 Ugain4 Ugain3 Ugain2 Ugain1 Ugain0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

IgainL

L Line Current rms Gain

IgainN

N Line Current rms Gain

Uoffset

Voltage Offset

Address: 32H

Type: Read/Write

Default Value: 7A13H

Bit Name Description

15 - 0 IgainL[15:0] L Line Current rms Gain, For details, please refer to application note AN-641.

Address: 33H

Type: Read/Write

Default Value: 7530H

Bit Name Description

15 - 0 IgainN[15:0] N Line Current rms Gain. For details, please refer to application note AN-641.

Address: 34H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 Uoffset[15:0] Voltage offset. For calculation method, please refer to application note AN-641.

15 14 13 12 11 10 9 8

IgainL15 IgainL14 IgainL13 IgainL12 IgainL11 IgainL10 IgainL9 IgainL8

76543210

IgainL7 IgainL6 IgainL5 IgainL4 IgainL3 IgainL2 IgainL1 IgainL0

15 14 13 12 11 10 9 8

IgainN15 IgainN14 IgainN13 IgainN12 IgainN11 IgainN10 IgainN9 IgainN8

76543210

IgainN7 IgainN6 IgainN5 IgainN4 IgainN3 IgainN2 IgainN1 IgainN0

15 14 13 12 11 10 9 8

Uoffset15 Uoffset14 Uoffset13 Uoffset12 Uoffset11 Uoffset10 Uoffset9 Uoffset8

76543210

Uoffset7 Uoffset6 Uoffset5 Uoffset4 Uoffset3 Uoffset2 Uoffset1 Uoffset0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

IoffsetL

L Line Current Offset

IoffsetN

N Line Current Offset

PoffsetL

L Line Active Power Offset

Address: 35H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 IoffsetL[15:0] L line current offset. For calculation method, please refer to application note AN-641.

Address: 36H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 IoffsetN[15:0] N line current offset. For calculation method, please refer to application note AN-641.

Address: 37H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 PoffsetL[15:0] L line active power offset.

Complement, MSB is the sign bit. For calculation method, please refer to application note AN-641.

15 14 13 12 11 10 9 8

IoffsetL15 IoffsetL14 IoffsetL13 IoffsetL12 IoffsetL11 IoffsetL10 IoffsetL9 IoffsetL8

76543210

IoffsetL7 IoffsetL6 IoffsetL5 IoffsetL4 IoffsetL3 IoffsetL2 IoffsetL1 IoffsetL0

15 14 13 12 11 10 9 8

IoffsetN15 IoffsetN14 IoffsetN13 IoffsetN12 IoffsetN11 IoffsetN10 IoffsetN9 IoffsetN8

76543210

IoffsetN7 IoffsetN6 IoffsetN5 IoffsetN4 IoffsetN3 IoffsetN2 IoffsetN1 IoffsetN0

15 14 13 12 11 10 9 8

PoffsetL15 PoffsetL14 PoffsetL13 PoffsetL12 PoffsetL11 PoffsetL10 PoffsetL9 PoffsetL8

76543210

PoffsetL7 PoffsetL6 PoffsetL5 PoffsetL4 PoffsetL3 PoffsetL2 PoffsetL1 PoffsetL0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

QoffsetL

L Line Reactive Power Offset

PoffsetN

N Line Active Power Offset

QoffsetN

N Line Reactive Power Offset

Address: 38H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 QoffsetL[15:0] L line reactive power offset.

Complement, MSB is the sign bit. For calculation method, please refer to application note AN-641.

Address: 39H

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 PoffsetN[15:0] N line active power offset.

Complement, MSB is the sign bit. For calculation method, please refer to application note AN-641.

Address: 3AH

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 QoffsetN[15:0] N line reactive power offset.

Complement, MSB is the sign bit. For calculation method, please refer to application note AN-641.

15 14 13 12 11 10 9 8

QoffsetL15 QoffsetL14 QoffsetL13 QoffsetL12 QoffsetL11 QoffsetL10 QoffsetL9 QoffsetL8

76543210

QoffsetL7 QoffsetL6 QoffsetL5 QoffsetL4 QoffsetL3 QoffsetL2 QoffsetL1 QoffsetL0

15 14 13 12 11 10 9 8

PoffsetN15 PoffsetN14 PoffsetN13 PoffsetN12 PoffsetN11 PoffsetN10 PoffsetN9 PoffsetN8

76543210

PoffsetN7 PoffsetN6 PoffsetN5 PoffsetN4 PoffsetN3 PoffsetN2 PoffsetN1 PoffsetN0

15 14 13 12 11 10 9 8

QoffsetN15 QoffsetN14 QoffsetN13 QoffsetN12 QoffsetN11 QoffsetN10 QoffsetN9 QoffsetN8

76543210

QoffsetN7 QoffsetN6 QoffsetN5 QoffsetN4 QoffsetN3 QoffsetN2 QoffsetN1 QoffsetN0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

CS2

Checksum 2

Address: 3BH

Type: Read/Write

Default Value: 0000H

Bit Name Description

15 - 0 CS2[15:0]

The CS2 register should be written after the 31H-3AH registers are written. Suppose the high byte and the low byte of the 31H-

3AH registers are shown in below table.

The calculatiion of the CS2 register is as follows:

The low byte of 3BH register is: L3B=MOD(H31+H32+...+H3A+L31+L32+...+L3A, 2^8)

The high byte of 3BH register is: H3B=H31 XOR H32 XOR ... XOR H3A XOR L31 XOR L32 XOR ... XOR L3A

For 90E21/22/23, a part of registers are not used. These registers can be dealed as 0000H in CS calculation.

The 90E21/22/23/24 calculates CS2 regularly. If the value of the CS2 register and the calculation by the 90E21/22/23/24 is differ-

ent when AdjStart=8765H, the AdjErr[1:0] bits (SysStatus, 01H) are set.

Note: The readout value of the CS2 register is the calculation by the 90E21/22/23/24, which is different from what is written.

15 14 13 12 11 10 9 8

CS2_15 CS2_14 CS2_13 CS2_12 CS2_11 CS2_10 CS2_9 CS2_8

76543210

CS2_7 CS2_6 CS2_5 CS2_4 CS2_3 CS2_2 CS2_1 CS2_0

31H H31 L31

32H H32 L32

33H H33 L33

34H H34 L34

35H H35 L35

36H H36 L36

37H H37 L37

38H H38 L38

39H H39 L39

3AH H3A L3A

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5.4 ENERGY REGISTER

Theory of Energy Registers

The internal energy resolution is 0.01 pulse. Within 0.01 pulse, forward and

reverse energy are counteracted. When energy exceeds 0.01 pulse, the respec-

tive forward/reserve energy is increased. The forward and reverse energy are

not counteracted in absolute energy registers. Take the example of active

energy, suppose:

T0: Forward energy is 12.34 pulses and reverse energy is 1.23 pulses;

From T0 to T1: 0.005 forward pulse appeared

From T1 to T2: 0.004 reverse pulse appeared

From T2 to T3: 0.003 reverse pulse appeared

When forward/reverse energy or absolute energy reaches 0.1 pulse, the respec-

tive register is updated. When forward/reverse energy or absolute energy

reaches 1 pulse, CFx pins output pulse and the REVP/REVQ bits (EnStatus,

46H) are updated.

Absolute energy might be more than the sum of forward and reverse energies. If

“consistency” is required between absolute energy and forward/reverse energy

in system application, absolute energy can be obtained by calculating the read-

out of the forward and reverse energy registers.

APenergy

Forward Active Energy

ANenergy

Reverse Active Energy

T0 T1 T2 T3

Forward Active Pulse 12.34 12.345 12.341 12.34

Reserve Active Pulse 1.23 1.23 1.23 1.232

Absolute Active Pulse 13.57 13.575 13.579 13.582

Address: 40H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 APenergy[15:0]

Forward active energy; cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

Address: 41H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 ANenergy[15:0]

Reverse active energy, cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

15 14 13 12 11 10 9 8

APenergy15 APenergy14 APenergy13 APenergy12 APenergy11 APenergy10 APenergy9 APenergy8

76543210

APenergy7 APenergy6 APenergy5 APenergy4 APenergy3 APenergy2 APenergy1 APenergy0

15 14 13 12 11 10 9 8

ANenergy15 ANenergy14 ANenergy13 ANenergy12 ANenergy11 ANenergy10 ANenergy9 ANenergy8

76543210

ANenergy7 ANenergy6 ANenergy5 ANenergy4 ANenergy3 ANenergy2 ANenergy1 ANenergy0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

ATenergy

Absolute Active Energy

RPenergy

Forward (Inductive) Reactive Energy

Address: 42H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 ATenergy[15:0]

Absolute active energy, cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

Address: 43H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 RPenergy[15:0]

Forward (inductive) reactive energy, cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

15 14 13 12 11 10 9 8

ATenergy15 ATenergy14 ATenergy13 ATenergy12 ATenergy11 ATenergy10 ATenergy9 ATenergy8

76543210

ATenergy7 ATenergy6 ATenergy5 ATenergy4 ATenergy3 ATenergy2 ATenergy1 ATenergy0

15 14 13 12 11 10 9 8

RPenergy15 RPenergy14 RPenergy13 RPenergy12 RPenergy11 RPenergy10 RPenergy9 RPenergy8

76543210

RPenergy7 RPenergy6 RPenergy5 RPenergy4 RPenergy3 RPenergy2 RPenergy1 RPenergy0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

RNenergy

Reverse (Capacitive) Reactive Energy

RTenergy

Absolute Reactive Energy

Address: 44H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 RNenergy[15:0]

Reverse (capacitive) reactive energy, cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

Address: 45H

Type: Read/Clear

Default Value: 0000H

Bit Name Description

15 - 0 RTenergy[15:0]

Absolute reactive energy, cleared after read.

Data format is XXXX.X pulses. Resolution is 0.1 pulse. Maximum is 6553.5 pulses.

When the accumulation of this register has achieved FFFFH, the continuation accumulation will return to 0000H.

15 14 13 12 11 10 9 8

RNenergy15 RNenergy14 RNenergy13 RNenergy12 RNenergy11 RNenergy10 RNenergy9 RNenergy8

76543210

RNenergy7 RNenergy6 RNenergy5 RNenergy4 RNenergy3 RNenergy2 RNenergy1 RNenergy0

15 14 13 12 11 10 9 8

RTenergy15 RTenergy14 RTenergy13 RTenergy12 RTenergy11 RTenergy10 RTenergy9 RTenergy8

76543210

RTenergy7 RTenergy6 RTenergy5 RTenergy4 RTenergy3 RTenergy2 RTenergy1 RTenergy0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

EnStatus

Metering Status

Address: 46H

Type: Read

Default Value After Power On: C800H

Bit Name Description

15 Qnoload

This bit indicates whether the chip is in reactive no-load status.

0: not reactive no-load state

1: reactive no-load state

14 Pnoload

This bit indicates whether the 90E21/22/23/24 is in active no-load status.

0: not active no-load state

1: active no-load state

13 RevQ

This bit indicates the direction of the last CF2 (reactive output).

0: reactive forward

1: reactive reverse

Note: This bit is always '0' when the CF2 output is configured to be absolute energy.

12 RevP

This bit indicates the direction of the last CF1 (active output).

0: active forward

1: active reverse

Note: This bit is always '0' when the CF1 output is configured to be absolute energy.

11 Lline

This bit indicates the current metering line in anti-tampering mode.

0: N line

1: L line

10 - 2 - Reserved.

1 - 0 LNMode[1:0]

These bits indicate the configuration of MMD1 and MMD0 pins. Their relationship is as follows:

15 14 13 12 11 10 9 8

Qnoload Pnoload RevQ RevP Lline - - -

76543210

- - - - - - LNMode1 LNMode0

MMD1 MMD0 LNmod1 LNmod0 L/N Metering Mode

0 0 0 0 anti-tampering mode (larger power)

0 1 0 1 L line mode (fixed L line)

1 0 1 0 L+N mode (applicable for single-phase three-wire system)

1 1 1 1 Flexible mode (Line specified by the LNSel bit (MMode, 2BH))

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

5.5 MEASUREMENT REGISTER

Irms

L Line Current rms

Urms

Voltage rms

Address: 48H

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Irms[15:0]

L line current rms.

Data format is XX.XXX, which corresponds to 0 ~ 65.535A.

For cases when the current exceeds 65.535A, it is suggested to be handled by MCU in application. For example, the register

value can be calibrated to 1/2 of the actual value during calibration, then multiplied by 2 in application.

Address: 49H

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Urms[15:0] Voltage rms.

Data format is XXX.XX, which corresponds to 0 ~ 655.35V.

15 14 13 12 11 10 9 8

Irms15 Irms14 Irms13 Irms12 Irms11 Irms10 Irms9 Irms8

76543210

Irms7 Irms6 Irms5 Irms4 Irms3 Irms2 Irms1 Irms0

15 14 13 12 11 10 9 8

Urms15 Urms14 Urms13 Urms12 Urms11 Urms10 Urms9 Urms8

76543210

Urms7 Urms6 Urms5 Urms4 Urms3 Urms2 Urms1 Urms0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Pmean

L Line Mean Active Power

Qmean

L Line Mean Reactive Power

Address: 4AH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Pmean[15:0]

L line mean active power.

Complement, MSB is the sign bit. Data format is XX.XXX, which corresponds to -32.768~+32.768kW.

If current is specially handle by MCU, the power of the 90E21/22/23/24 and the actual power have the same multiple relationship

as the current.

Address: 4BH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Qmean[15:0]

L line mean reactive power.

Complement, MSB is the sign bit. Data format is XX.XXX, which corresponds to -32.768~+32.768kvar.

If current is specially handled by MCU, the power of the 90E22/24 and the actual power have the same multiple relationship as

the current.

15 14 13 12 11 10 9 8

Pmean15 Pmean14 Pmean13 Pmean12 Pmean11 Pmean10 Pmean9 Pmean8

76543210

Pmean7 Pmean6 Pmean5 Pmean4 Pmean3 Pmean2 Pmean1 Pmean0

15 14 13 12 11 10 9 8

Qmean15 Qmean14 Qmean13 Qmean12 Qmean11 Qmean10 Qmean9 Qmean8

76543210

Qmean7 Qmean6 Qmean5 Qmean4 Qmean3 Qmean2 Qmean1 Qmean0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Freq

Voltage Frequency

PowerF

L Line Power Factor

Pangle

Phase Angle between Voltage and L Line Current

Address: 4CH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Freq[15:0] Voltage frequency.

Data format is XX.XX. Frequency measurement range is 45.00~65.00Hz. For example, 1388H corresponds to 50.00Hz.

Address: 4DH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 PowerF[15:0]

L line power factor.

Signed, MSB is the sign bit. Data format is X.XXX. Power factor range: -1.000~+1.000. For example, 03E8H corresponds to the

power factor of 1.000, and 83E8H corresponds to the power factor of -1.000.

Address: 4EH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Pangle[15:0] L line voltage current angle.

Signed, MSB is the sign bit. Data format is XXX.X. Angle range: -180.0~+180.0 degree.

15 14 13 12 11 10 9 8

Freq15 Freq14 Freq13 Freq12 Freq11 Freq10 Freq9 Freq8

76543210

Freq7 Freq6 Freq5 Freq4 Freq3 Freq2 Freq1 Freq0

15 14 13 12 11 10 9 8

PowerF15 PowerF14 PowerF13 PowerF12 PowerF11 PowerF10 PowerF9 PowerF8

76543210

PowerF7 PowerF6 PowerF5 PowerF4 PowerF3 PowerF2 PowerF1 PowerF0

15 14 13 12 11 10 9 8

Pangle15 Pangle14 Pangle13 Pangle12 Pangle11 Pangle10 Pangle9 Pangle8

76543210

Pangle7 Pangle6 Pangle5 Pangle4 Pangle3 Pangle2 Pangle1 Pangle0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Smean

L Line Mean Apparent Power

Irms2

N Line Current rms

Address: 4FH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Smean[15:0]

L line mean apparent power.

Complement, MSB is always '0'. Data format is XX.XXX, which corresponds to 0~+32.767kVA.

If current is specially handled by MCU, the power of the 90E21/22/23/24 and the actual power have the same multiple relation-

ship as the current.

Address: 68H

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Irms2[15:0]

N line current rms.

Data format is XX.XXX, which corresponds to 65.535A.

For cases when the current exceeds 65.535A, it is suggested to be handled by MCU in application. For example, the register

value can be calibrated to 1/2 of the actual value during calibration, then multiplied by 2 in application.

15 14 13 12 11 10 9 8

Smean15 Smean14 Smean13 Smean12 Smean11 Smean10 Smean9 Smean8

76543210

Smean7 Smean6 Smean5 Smean4 Smean3 Smean2 Smean1 Smean0

15 14 13 12 11 10 9 8

Irms2_15 Irms2_14 Irms2_13 Irms2_12 Irms2_11 Irms2_10 Irms2_9 Irms2_8

76543210

Irms2_7 Irms2_6 Irms2_5 Irms2_4 Irms2_3 Irms2_2 Irms2_1 Irms2_0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Pmean2

N Line Mean Active Power

Qmean2

N Line Mean Reactive Power

Address: 6AH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Pmean2[15:0]

N line mean active power.

Complement, MSB is the sign bit. Data format is XX.XXX, which corresponds to -32.768~+32.767kW.

If current is specially handled by MCU, the power of the 90E21/22/23/24 and the actual power have the same multiple relation-

ship as the current.

Address: 6BH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Qmean2[15:0]

N line mean reactive power.

Complement, MSB is the sign bit. Data format is XX.XXX, which corresponds to -32.768~+32.767kvar.

If current is specially handled by MCU, the power of 90E22/24 and the actual power have the same multiple relationship as the

current.

15 14 13 12 11 10 9 8

Pmean2_15 Pmean2_14 Pmean2_13 Pmean2_12 Pmean2_11 Pmean2_10 Pmean2_9 Pmean2_8

76543210

Pmean2_7 Pmean2_6 Pmean2_5 Pmean2_4 Pmean2_3 Pmean2_2 Pmean2_1 Pmean2_0

15 14 13 12 11 10 9 8

Qmean2_15 Qmean2_14 Qmean2_13 Qmean2_12 Qmean2_11 Qmean2_10 Qmean2_9 Qmean2_8

76543210

Qmean2_7 Qmean2_6 Qmean2_5 Qmean2_4 Qmean2_3 Qmean2_2 Qmean2_1 Qmean2_0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

PowerF2

N Line Power Factor

Pangle2

Phase Angle between Voltage and N Line Current

Address: 6DH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 PowerF2[15:0]

N line power factor.

Signed, MSB is the sign bit. Data format is X.XXX. Power factor range: -1.000~+1.000. For example, 03E8H corresponds to the

power factor of 1.000, and 83E8H corresponds to the power factor of -1.000.

Address: 6EH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Pangle2[15:0] N line voltage current angle

Signed, MSB is the sign bit. Data format is XXX.X. Angle range: -180.0~+180.0 degree.

15 14 13 12 11 10 9 8

PowerF2_15 PowerF2_14 PowerF2_13 PowerF2_12 PowerF2_11 PowerF2_10 PowerF2_9 PowerF2_8

76543210

PowerF2_7 PowerF2_6 PowerF2_5 PowerF2_4 PowerF2_3 PowerF2_2 PowerF2_1 PowerF2_0

15 14 13 12 11 10 9 8

Pangle2_15 Pangle2_14 Pangle2_13 Pangle2_12 Pangle2_11 Pangle2_10 Pangle2_9 Pangle2_8

76543210

Pangle2_7 Pangle2_6 Pangle2_5 Pangle2_4 Pangle2_3 Pangle2_2 Pangle2_1 Pangle2_0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Smean2

N Line Mean Apparent Power

Address: 6FH

Type: Read

Default Value: 0000H

Bit Name Description

15 - 0 Smean2[15:0]

N line mean apparent power

Complement, MSB is always '0'. Data format is XX.XXX, which corresponds to 0~+32.767kVA.

If current is specially handled by MCU, the power of 90E21/22/23/24 and the actual power have the same multiple relationship as

the current.

15 14 13 12 11 10 9 8

Smean2_15 Smean2_14 Smean2_13 Smean2_12 Smean2_11 Smean2_10 Smean2_9 Smean2_8

76543210

Smean2_7 Smean2_6 Smean2_5 Smean2_4 Smean2_3 Smean2_2 Smean2_1 Smean2_0

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 48 April 2, 2013

6 ELECTRICAL SPECIFICATION

6.1 ELECTRICAL SPECIFICATION

Parameters and Description Min. Typical Max. Unit Test Conditions and Comments

Accuracy

DC Power Supply Rejection Ratio (PSRR) ±0.1 %

VDD=3.3V±0.3V, 100Hz, I=5A, V=220V, L line

shunt resistor 150μΩ, N line CT 1000:1, sampling

resistor 4.8Ω

AC Power Supply Rejection Ratio (PSRR) ±0.1 %

VDD=3.3V superimposes 400mVrms, 100Hz Sinu-

soidal signal, I=5A, V=220V, L line shunt resistor

150μΩ, N line CT 1000:1, sampling resistor 4.8Ω

Active Energy Error (Dynamic Range 5000:1) ±0.1 % L line current gain is ‘24’; N line current gain is ‘1’

Channel Characteristics

Sampling Frequency 8kHz

L Line Current Channel Equivalent Input Noise 19.1

Single side band noise (measured at 50Hz, and

PGA gain is ‘24’)

N Line Current Channel Equivalent Input Noise 458.4

Single side band noise (measured at 50Hz, and

PGA gain is ‘1’)

Voltage Channel Equivalent Input Noise 458.4

Single side band noise (measured at 50Hz, and

PGA gain is ‘1’)

Total Harmonic Distortion for Each Channel 80 dB 25°C, PGA gain is ‘1’, 500mVrms input

Reactive Energy Metering Bandwidth 4 kHz

Active Energy Metering Bandwidth 4 kHz

Irms and Vrms Measurement Bandwidth 4 kHz

Measurement Error ±0.5 %

Analog Input

L Line Current Channel Differential Input

5μ25m

Vrms

PGA gain is ‘24’

7.5μ37.5m PGA gain is ‘16’

15μ75m PGA gain is ‘8’

30μ150m PGA gain is ‘4’

120μ600m PGA gain is ‘1’

N Line Current Channel Differential Input

30μ150m

Vrms

PGA gain is ‘4’

60μ300m PGA gain is ‘2’

120μ600m PGA gain is ‘1’

Voltage Channel Differential Input 120μ600m Vrms PGA gain is ‘1’

L Line Current Channel Input Impedance 1 KΩ

N Line Current Channel Input Impedance 50 KΩ

Voltage Channel Input Impedance 50 KΩ

L Line Current Channel DC Offset 10 mV PGA gain is ‘24’

N Line Current Channel DC Offset 10 mV PGA gain is ‘1’

Voltage Channel DC Offset 10 mV PGA gain is ‘1’

Reference

On-Chip Reference (90E21/22/23/24) 1.398 1.417 1.440 V Reference voltage test mode

Reference Voltage Temperature Coefficient ±15 ±40 ppm/°C

Clock

Crystal or External Clock 8.192 MHz

The Accuracy of crystal or external clock is ±100

ppm

SPI Interface

SPI Interface Bit Rate 200 160k bps

Pulse Width

CFx Pulse Width 80 ms

If T ≥160 ms, width=80ms; if T<160 ms, width =

0.5T. Refer to Section 6.6

ESD

Machine Model (MM) 400 V JESD22-A115

Charged Device Model (CDM) 1000 V JESD22-C101

Hz/nV

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 49 April 2, 2013

Human Body Model (HBM) 4000 V JESD22-A114

Latch Up ±100 mA JESD78A

Latch Up 4.95 V JESD78A

Operating Conditions

AVDD, Analog Power Supply 2.8 3.3 3.6 V Metering precision guaranteed within 3.0V~3.6V.

DVDD, Digital Power Supply 2.8 3.3 3.6 V Metering precision guaranteed within 3.0V~3.6V.

IAVDD, Analog Current (90E21/22) 3.00 mA

L line current channel and voltage channel are

open

IAVDD, Analog Current (90E23/24) 3.75 mA

L line/ N line current channel and voltage channel

are open

IDVDD, Digital Current 2.75 mA VDD=3.3V

DC Characteristics

Digital Input High Level (all digital pins except OSCI) 2.0 VDD+2.6 V VDD=3.3V±10%,

Digital Input High Level (OSCI) 2.0 VDD+0.3 V VDD=3.3V±10%

Digital Input Low Level 0.8 V VDD=3.3V±10%

Digital Input Leakage Current ±1μA VDD=3.6V, VI=VDD or GND

Digital Output Low Level (CF1, CF2) 0.4 V VDD=3.3V, IOL=10mA

Digital Output Low Level (IRQ, WarnOut, ZX, SDO) 0.4 V VDD=3.3V, IOL=5mA

Digital Output High Level (CF1, CF2) 2.4 V VDD=3.3V, IOH=-10mA

Digital Output High Level (IRQ, WarnOut, ZX, SDO) 2.4 V VDD=3.3V, IOH=-5mA

Digital Output Low Level (OSCO) 0.4 V VDD=3.3V, IOL=1mA

Digital Output High Level (OSCO) 2.4 V VDD=3.3V, IOH=-1mA

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 50 April 2, 2013

6.2 SPI INTERFACE TIMING

The SPI interface timing is as shown in Figure-10, Figure-11 and

Table-12.

Figure-10 4-Wire SPI Timing Diagram

Figure-11 3-Wire SPI Timing Diagram

Table-12 SPI Timing Specification

Symbol Description Min. Typical Max. Unit

tCSH

note 1

Minimum CS High Level Time 30T

note 2

+10 ns

tCSS

note 1

CS Setup Time 3T+10 ns

tCSD

note 1

CS Hold Time 30T+10 ns

tCLD

note 1

Clock Disable Time 1T ns

tCLH Clock High Level Time 30T+10 ns

tCLL Clock Low Level Time 16T+10 ns

tDIS Data Setup Time 3T+10 ns

tDIH Data Hold Time 22T+10 ns

SCLK

SDI

SDO

tCSH

tCSS

High Impedance High Impedance

tCSD

tCLH tCLL

tDIS tDIH

tPD tDF

Valid Input

Valid Output

tCLD

tDW

SCLK

SDI

SDO High Impedance High Impedance

tCLH tCLL

tDIS tDIH

tPD

Valid Input

Valid Output

tDW

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 51 April 2, 2013

6.3 POWER ON RESET TIMING

Figure-12 Power On Reset Timing Diagram

6.4 ZERO-CROSSING TIMING

Figure-13 Zero-Crossing Timing Diagram

tDW Minimum Data Width 30T+10 ns

tPD Output Delay 14T 15T+20 ns

tDF

note 1

Output Disable Time 16T+20 ns

Note:

1. Not applicable for three-wire SPI.

2. T means SCLK cycle. T=122ns. (Typical value for four-wire SPI)

Table-12 SPI Timing Specification (Continued)

Table-13 Power On Reset Specification

Symbol Description Min. Typical Max. Unit

VHPower On Trigger Voltage 2.47 2.6 2.73 V

VLPower Off Trigger Voltage 2.185 2.3 2.415 V

VH-VLHysteretic Voltage Difference 0.285 0.3 0.315 V

T1Delay Time After Power On 5 ms

T2Delay Time After Power Off 10 μs

DVDD

RESET

(Positive zero-crossing)

(Negative zero-crossing)

(All zero-crossing)

TZX

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 52 April 2, 2013

6.5 VOLTAGE SAG TIMING

Figure-14 Voltage Sag Timing Diagram

6.6 PULSE OUTPUT

Figure-15 Output Pulse Width

Table-14 Zero-Crossing Specification

Symbol Description Min. Typical Max. Unit

TZX High Level Width 5 ms

TDDelay Time 0.5 ms

Table-15 Voltage Sag Specification

Symbol Description Min. Typical Max. Unit

TDDelay Time 0.5 ms

Voltage Sag

Threshold

WarnOut

IRQ

Voltage Sag

Threshold

CFx

Tp=80ms

Tp=0.5T

T≥160ms 10ms≤T<160ms

Tp=5ms

if T<10ms,

force T=10ms

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

Electrical Specification 53 April 2, 2013

6.7 ABSOLUTE MAXIMUM RATING

Parameter Maximum Limit

Relative Voltage Between AVDD and AGND -0.3V~3.7V

Relative Voltage Between DVDD and DGND -0.3V~3.7V

Analog Input Voltage (I1P, I1N, I2P, I2N, VP, VN) -1V~VDD

Digital Input Voltage -0.3V~VDD+2.6V

Operating Temperature Range -40~85 °C

Maximum Junction Temperature 150 °C

Package Type Thermal Resistance θJA Unit Condition

Green SSOP28 63.2 °C/W No Airflow

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

54 April 2, 2013

PACKAGE DIMENSIONS

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

55 April 2, 2013

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

56 April 2, 2013

90E21/22/23/24 SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC

ORDERING INFORMATION

DATASHEET DOCUMENT HISTORY

09/02/2010 pg. 16

11/02/2010 pg. 37, 40

12/13/2010 pg. 6, 10, 48, 52

12/27/2010 pg. 48

03/22/2011 pg. 53

01/10/2012 pg. 48, 52, 54, 55, 56

XXXXX XXX X

Device Type

Temperature Range

90E21

Industry (-40 ℃to +85 ℃)

Single-Phase High-Performance

Wide-Span Energy Metering IC

PYG Green SSOP28

90E22

90E23

90E24

Package