LM25056APSQ/NOPB - Texas Instruments

LM25056A

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LM25056A System Power Measurement IC with PMBus

Check for Samples: LM25056A

1FEATURES APPLICATIONS

234• Input Voltage Range: 3V to 17V • Server Backplane Systems

• I2C/SMBus Interface with PMBus Compliant • Base Station Power Distribution Systems

Command Structure • Subsystem Power Measurement

• Remote Temperature Sensing with

Programmable Warning and Shutdown DESCRIPTION

Thresholds The LM25056A combines high performance analog

and digital technology with a PMBus™ compliant

• Real Time Monitoring of VIN, IIN, PIN, VAUX with SMBus™/I2C interface to accurately measure the

12-bit Resolution and 1 kHz Sampling Rate operating conditions of electrical systems including

• Current Measurement Error: ±0.5%: +10°C to computing and storage blades connected to a

+85°C backplane power bus. The LM25056A continuously

• Voltage Measurement Error: ±1.0%: +10°C supplies real-time power, voltage, current, and

temperature data to the system management host via

to+85°C the SMBus interface.

• Power Measurement Error: ±1.5%: +10°C to

+85°C The LM25056A monitoring block captures both real-

time and average values of subsystem operating

• True Input Power Measurement Using parameters (VIN, IIN, PIN, VAUX) as well as peak

Simultaneous Sampling of VIN and IIN power. Accurate power measurement is

Accurately Averages Dynamic Power Readings accomplished by measuring the product of the input

• Averaging of VIN, IIN, PIN, and VAUX Over voltage and current through a shunt resistor.

Programmable Interval Ranging from 0.001 to LM25056A current measurement has a ±0.5%

4 Seconds accuracy over the temperature range of +10°C to

+85°C with operation from -40°C to +125°C. A black

• User Programmable WARN and FAULT box (Telemetry/Fault Snapshot) function captures and

Thresholds with SMBA Notification stores telemetry data and device status in the event

• Black Box Capture of Telemetry of a warning or a fault.

Measurements and Device Status Triggered by

WARN and FAULT Conditions

• Full Featured Application Development

Software

• WQFN-24 Package

1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2SMBus is a trademark of Intel Corp..

3PMBus is a trademark of SMIF, Inc..

4All other trademarks are the property of their respective owners.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

ADR2

ADR1

VAUX

SCL

SMBA

VREF

DIODE

AGND

ADR0

SDA

VDD

Exposed Pad

VS+

VIN

DGND

ENABLE

VS-

SDA

SCL

SMBA

VREF

DIODE

ADR0

ADR1

ADR2

VDD

DGND AGND

VAUX

ENABLE

VIN VS+ VS-

SMBus

Interface

MMBT3904

POL

REGULATOR

LM25056

+12V

CVDD

VIN

VOUT

CVREF

VDD

CIN

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Typical Application Schematic

Connection Diagram

Solder exposed pad to ground.

Figure 1. Top View

WQFN-24

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PIN DESCRIPTIONS

Pin Name Description Applications Information

No.

PAD Exposed Exposed pad of WQFN No internal electrical connections. Solder to the ground plane to reduce thermal

Pad package resistance.

1 ADR2 SMBus address line 2 3 - state address line. Should be connected to GND, VDD, or left floating.

2 ADR1 SMBus address line 1 3 - state address line. Should be connected to GND, VDD, or left floating.

3 ADR0 SMBus address line 0 3 - state address line. Should be connected to GND, VDD, or left floating.

4 VDD Internal sub-regulator Internally sub-regulated 3.7V bias supply. Connect a 1 µF capacitor on this pin to ground

output for bypassing. VDD can be driven from an external voltage for low voltage operation.

5 NC No Connect Not bonded to die. Can be connected to the ground plane.

6 NC No Connect Not bonded to die. Can be connected to the ground plane.

7 NC No Connect Not bonded to die. Can be connected to the ground plane.

8 VS- Current sense input (-) Negative IIN sense amplifer input. The voltage across the current sense resistor (RS) is

measured from VS+ to this pin.

9 VS+ Current sense input (+) Positive IIN sense amplifier input. The voltage across the current sense resistor (RS) is

measured from this pin to VS-.

10 NC No Connect Not bonded to die. Can be connected to the ground plane.

11 VIN Positive supply input A small 0.1 µF ceramic bypass capacitor close to this pin is recommended. VIN is

measured from this pin.

12 ENABLE Enable Enable pin. This pin has a rising threshold of +1.2V to enable the LM25056A. Lowering

this pin below the 75mV hysteresis from the +1.2V threshold will put the part into power

down mode.

13 VAUX Auxiliary voltage input Auxiliary pin allows voltage telemetry from an external source. Full scale input of 1.2V

14 NC No Connect Not bonded to die. Can be connected to the ground plane.

15 NC No Connect Not bonded to die. Can be connected to the ground plane.

16 NC No Connect Not bonded to die. Can be connected to the ground plane.

17 AGND Analog ground Connect analog ground to digital ground and then to a quiet system ground. Be sure to

avoid high current return ground lines.

18 NC No Connect Not bonded to die. Can be connected to the ground plane.

19 DGND Digital ground Connect analog ground to digital ground and then to a clean system ground. Be sure to

avoid high current return ground lines.

20 SDA SMBus data pin Data pin for SMBus.

21 SCL SMBus clock Clock pin for SMBus.

22 SMBA SMBus alert line Alert pin for SMBus. Active low.

23 VREF Internal reference Internally generated precision 2.82V reference used for analog to digital conversion.

Connect a 1 µF ceramic capacitor on this pin to ground for bypassing.

24 DIODE External diode Connect this to a diode-configured MMBT3904 NPN transistor for temperature monitoring.

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

Absolute Maximum Ratings(1)(2)

VIN, VS-, VS+ to AGND/DGND -0.3V to 24V

SCL, SDA, SMBA, ADR0, ADR1, ADR2, VDD, VAUX, DIODE, ENABLE to AGND/DGND -0.3V to 6V

VS+ to VS- -0.3V to +0.3V

ESD Rating(3) Human Body Model 2kV

Storage Temperature -65°C to +150°C

Junction Temperature +150°C

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is intended to be functional. For specifications and conditions see the Electrical Characteristics.

(2) If Military/Aerospace specified devices are required, please contact the TI Office/Distributors for availability and specifications.

(3) The human body model is a 100 pF capacitor discharged through a 1.5 kΩresistor into each pin.

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Operating Ratings

VIN, VS-, VS+ voltage 3V to 17V

VDD 3V to 5.5V

Junction Temperature -40°C to +125°C

Electrical Characteristics

Limits in standard type are for TJ= +25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C

to +85°C unless otherwise stated. Minimum and Maximum limits are specified through test, design, or statistical correlation.

Typical values represent the most likely parametric norm at TJ= +25°C, and are provided for reference purposes only. Unless

otherwise stated the following conditions apply: VIN = 12V. See (1) and (2).

Symbol Parameter Conditions Min. Typ. Max. Units

Input (VIN Pin)

ISUPPLY-EN Supply current, enabled ENABLE > 1.2V 1.7 2.8 mA

ISUPPLY-DIS Supply current, disabled ENABLE < 1.2V 10 100 µA

VREF Reference

VREF Reference voltage 2.82 V

VDD Regulator (VDD pin)

VDD 3.1 3.7 4.1 V

IVDDLIM VDD current limit VIN = 12V 50 mA

PORVDD Power on reset threshold at VDD VDD increasing 2.4 3.0 V

PORHYS POR hysteresis VDD decreasing 90 mV

ADC and MUX

Resolution 12 Bits

tRR Acquisition round robin time Update all telemetry channels 1 ms

Telemetry Accuracy

IINIB Current sense input bias current 20 µA

IINFSR Current sense full scale range, VSENSE = GAIN = 0 29.68 mV

VS+ −VS- GAIN = 1 60.88 mV

IINLSB Current sense input LSB GAIN = 0 7.25 µV

GAIN = 1 14.87 µV

VAUXFSR VAUX input full scale range (ADC native 1.199 V

range)

VAUXLSB VAUX input LSB 293 µV

VINFSR Supply voltage measurement full scale For calculation only, observe maximum 25.13 V

range voltage ratings.

VINLSB Supply voltage measurement LSB 6.14 mV

IINERR Current sense measurement error GAIN = 0, VSENSE = 25 mV, -0.5 +0.5 %

+10°C to +85C

IINERR Current sense measurement error GAIN = 0, VSENSE = 25 mV -1.5 +1.5 %

IINERR Current sense measurement error GAIN = 0, VSENSE = 5 mV, -5 +5 %

+10°C to +85C

IINERR Current sense measurement error GAIN = 1, VSENSE = 55 mV, 1 %

PERR Input power measurement error GAIN = 0, VIN = 12V, VSENSE = 25 mV, -1.5 +1.5 %

+10°C to +85C

PERR Input power measurement error GAIN = 0, VIN = 12V, VSENSE = 25 mV -3 +3 %

PERR Input power measurement error GAIN = 1, VIN = 12V, VSENSE = 55 mV 2 %

VINERR Input voltage measurement error VIN = 12V, +10°C to +85C -1.0 +1.0 %

VINERR Input voltage measurement error VIN = 12V -1.5 +1.5 %

VAUXERR Auxiliary measurement error VAUX = 1V, +10°C to +85C -1.5 +1.5 %

(1) Current out of a pin is indicated as a negative value.

(2) All electrical characteristics having room temperature limits are tested during production at TA= +25°C. All bold limits are specified by

correlating the electrical characteristics to process and temperature variations and applying statistical process control.

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Electrical Characteristics (continued)

Limits in standard type are for TJ= +25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C

to +85°C unless otherwise stated. Minimum and Maximum limits are specified through test, design, or statistical correlation.

Typical values represent the most likely parametric norm at TJ= +25°C, and are provided for reference purposes only. Unless

otherwise stated the following conditions apply: VIN = 12V. See (1) and (2).

Symbol Parameter Conditions Min. Typ. Max. Units

VAUXERR Auxiliary measurement error VAUX = 1V -2.5 +2.5 %

Remote Diode Temperature Sensor

TACC Temperature accuracy using local diode 3 °C

Remote diode resolution 9 bits

IDIODE External diode current source High Level 240 325 µA

Low Level 9.2 µA

Diode Current 26

Ratio

PMBus Pin Thresholds (SMBA, SDA, SCL)

VIL Data, clock input low voltage 0.9 V

VIH Data, clock input high voltage 2.1 5.5 V

VOL Data output low voltage IPULLUP = 5 mA 0 0.4 V

ILEAK Input leakage current SDA, SMBA, SCL = 5.5V 1µA

ENABLE Pin

VEN ENABLE threshold voltage Rising threshold 1.4 1.2 V

VEN-HYS ENABLE threshold voltage hysteresis 75 mV

ILEAK Input Leakage Current ENABLE = 5V 1mA

IPULLUP ENABLE pin pullup current 2.8 µA

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-40 -20 0 20 40 60 80 100 120 140

2.20

2.25

2.30

2.35

2.40

2.46

2.50

VOLTAGE (V)

TEMPERATURE (°C)

Rising

Falling

-40 -20 0 20 40 60 80 100120140

1.10

1.15

1.20

1.25

1.30

VOLTAGE (V)

TEMPERATURE (°C)

Rising

Falling

-40 -20 0 20 40 60 80 100 120 140

CURRENT (A)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

CURRENT (A)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

1.2

1.3

1.4

1.5

1.6

1.7

1.8

CURRENT (mA)

TEMPERATURE (°C)

5V, 12V, 17V

-40 -20 0 20 40 60 80 100 120 140

CURRENT (A)

TEMPERATURE (°C)

12V

17V

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Typical Performance Characteristics

Unless otherwise specified the following conditions apply: TJ= +25°C, VIN = 12V. All graphs show junction temperature.

VIN Pin Current (Enabled) VIN Pin Current (Disabled)

Figure 2. Figure 3.

VS+ Pin Input Bias Current (Enabled) VS- Pin Input Bias Current (Enabled)

Figure 4. Figure .

POR Threshold ENABLE Threshold

Figure 5. Figure 6.

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-40 -20 0 20 40 60 80 100 120 140

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

IIN ERROR (%)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

PIN ERROR (%)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

VIN ERROR (%)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

VAUX ERROR (%)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

2.800

2.805

2.810

2.815

2.820

2.825

2.830

2.835

2.840

VOLTAGE (V)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

3.67

3.68

3.69

3.70

3.71

3.72

3.73

VOLTAGE (V)

TEMPERATURE (°C)

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Typical Performance Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= +25°C, VIN = 12V. All graphs show junction temperature.

VREF Voltage VDD Voltage

Figure 7. Figure 8.

VIN Error, VIN=12V VAUX Error, VAUX=1V

Figure 9. Figure 10.

IIN Error, GAIN=0, VSENSE=25mV PIN Error, GAIN=0, VIN=12V, VSENSE=25mV

Figure 11. Figure 12.

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-40 -20 0 20 40 60 80 100 120 140

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

IIN ERROR (%)

TEMPERATURE (°C)

-40 -20 0 20 40 60 80 100 120 140

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

PIN ERROR (%)

TEMPERATURE (°C)

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Typical Performance Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= +25°C, VIN = 12V. All graphs show junction temperature.

IIN Error, GAIN=1, VSENSE=55mV PIN Error, GAIN=1, VIN=12V, VSENSE=55mV

Figure 13. Figure 14.

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Address

Decoder

SMBus

Interface

VS+

VS-

VIN

VDD

3.7V

ENABLE

SMBA

SDA

SCL

ADR2

ADR1

ADR0

AGND

DGND

1/21

VDD

REG

REF

GEN

BUF

S/H

12 bit

ADC

AMUX

Measurement/

Averaging

Warning Registers

Telemetry State

Machine

Diode

Temp

Sense

Black Box

DIODE

VAUX

VREF

2.82V 20x, GAIN=0

40x, GAIN=1

2.35x 1.2V

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Block Diagram

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LM25056

+12V

GND

VIN

ENABLE

SHUTDOWN

CONTROL

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FUNCTIONAL DESCRIPTION

The LM25056A provides intelligent monitoring of the input voltage, input current, input power, temperature, and

an auxiliary input. The LM25056A also provides a peak capture of the input power and programmable hardware

averaging of the input voltage, current, power, temperature, and the auxiliary voltage. Warning thresholds which

trigger the SMBA pin may be programmed for input and auxiliary voltage, current, power, and temperature via

the PMBus interface.

Enabling/Disabling and Resetting

The LM25056A has an ENABLE pin that can be used to power on and off the device. If desired, the LM25056A

can be kept in shutdown until the supply reaches a particular threshold using ENABLE with a resistor divider or

with an active control as shown in Figure 15.

Figure 15. ENABLE Control

When taken low, this logic pin will reduce the quiescent current for the device and will no longer respond to

PMBus commands. Also, taking the ENABLE low is a functional reset of the LM25056A. Raising ENABLE sets

the part to its default operation. If this functionality is not used, then ENABLE should be left floating (an internal

pull-up will maintain its operation) or tied to an external VDD voltage. Do not tie ENABLE to the onboard VDD.

The VDD power-up is delayed and when power is first applied, and VDD starts low. This in turn will keep

ENABLE low and the LM25056A will not start up.

VDD and VREF also have a power-on-reset (POR) circuit that holds the LM25056A in reset until it reaches the

operating state. Note that if either of these output lines are inadvertently pulled low, the device is reset to its

initial default state, erasing the volatile memory the same as ENABLE pulled low. Once VDD and VREF have

reached the POR threshold of 2.4V, the device comes out of reset.

As an example, the SMBus address of the LM25056A is captured based on the states (GND, NC, VDD) of the

ADR0, ADR1, and ADR2 pins during turn on and is latched into a volatile register once the ENABLE pin is

determined to be high and the VDD and VREF has exceeded its POR threshold of 2.4V. Reassigning or

postponing the address capture can be accomplished by holding the ENABLE pin to AGND. For more

information on the operation of these pins, please see the PMBus Address Lines section of this datasheet.

The logic and volatile memory can also be reset with a PMBus write to the MFR_DEVICE_SETUP (D9h) register

into the software reset bit. However, this software reset will not trigger a read of the states of the address pins as

the ENABLE pin or VDD and VREF POR events will.

VDD Sub-Regulator

The LM25056A contains an internal linear sub-regulator which steps down the input voltage to generate a 3.7V

rail used for powering low voltage and low power circuitry. When the input voltage is below 3.7V, VDD will track

VIN. For input voltages 3.3V and below, VDD should be tied directly to VIN to avoid the dropout of the sub-

regulator. The VDD sub-regulator should be used as the pull-up supply for the ADR2, ADR1, and ADR0 pins if

they are to be tied high. It may also be used as the pull-up supply for SMBus signals (SDA, SCL, SMBA). The

VDD sub-regulator is not designed to drive high currents and should not be loaded to drive high current circuits.

The VDD pin is current limited to 50 mA in order to protect the LM25056A in the event of a short. The sub-

regulator requires a ceramic bypass capacitance of 1 µF or greater to be placed as close to VDD as the PCB

layout allows.

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SDA

SCL

SMBA

VREF

DIODE

ADR0

ADR1

ADR2

VDD

DGND AGND

VAUX

ENABLE

VIN VS+ VS-

SMBus

Interface

MMBT3904

POL

REGULATOR

LM25056

+12V

CVDD

VIN

VOUT

CVREF

VDD

CIN

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Additionally, VDD can be driven from an external source to maintain telemetry readings for VIN and temperature

if the VIN drops below its operation point. To do this, use an external 5V supply driving the VDD through a

Schottky diode. This allows for telemetry readings down to VIN=0. A large capacitor (100uF) can also be placed

at on the VDD line to momentarily supply current to the device to similarly maintain telemetry readings that would

normally shutdown and reset the device. Note that when using an external VDD drive, ENABLE will not operate

independently. To use this functionality, simply connect the external VDD source to ENABLE and lower this

source to put the LM25056A into low power mode.

Remote Temperature Sensing

The LM25056A is designed to measure temperature remotely using an MMBT3904 NPN transistor. The base

and collector of the MMBT3904 should be connected to the DIODE pin and the emitter of the MMBT3904

connected to AGND. Place the MMBT3904 near the device whose temperature is to be monitored. In noisy

environments with large currents or switching noise, it is especially important to bring this connection back to

AGND and not just to the nearest ground plane. If the temperature of a pass MOSFET is to be measured, the

MMBT3904 should be placed as close to device as the layout allows. The temperature is measured by means of

a change in an external diode voltage in response to a step in current supplied by DIODE. DIODE sources 9.2

µA but pulses 240 µA once every millisecond in order to measure the diode temperature. Care must be taken in

the PCB layout to keep the parasitic resistance between DIODE and the MMBT3904 low so as not to degrade

the measurement. Additionally, a small 100 pF bypass capacitor can be placed in parallel with the MMBT3904 to

reduce the effects of noise. The temperature can be read using the READ_TEMPERATURE_1 PMBus command

(8Dh). The default warning limit of the LM25056A will cause SMBA to be pulled low if the measured temperature

code exceeds 07D0h. The PMBus will also indicate an over temperature fault if the measured temperature code

exceeds 0960h. These thresholds can be reprogrammed via the PMBus interface using the OT_WARN_LIMIT

(51h) and OT_FAULT_LIMIT (4Fh) commands. If the temperature measurement and protection capability of the

LM25056A is not used the DIODE pin should be grounded.

Application Section

Figure 16. Typical Application Circuit

DESIGN-IN PROCEDURE

(Refer to Figure 16 for Typical Application Circuit) Shown here is the step-by-step procedure for hardware design

of the LM25056A. This procedure refers to section numbers that provide detailed information on the following

design steps. The recommended design-in procedure is as follows:

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SENSE

RESISTOR

VS+ VS-

FROM SYSTEM

INPUT VOLTAGE TO LOAD

SENSE CURRENT PATH

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Current Range, RS:Determine the current range based on the voltage dropped across the sense resistor (RS).

Depending on the GAIN setting, the voltage across the sense resistor to get a full scale reading for the current

measurement should be 30 mV for GAIN=0 and 60 mV for GAIN=1. Use the Equation 1 to determine the value

for RS.

Refer to Programming Guide section: After all hardware design is complete, refer to the programming guide

for a step by step procedure regarding software.

CURRENT RANGE, (RS)

The LM25056A monitors current by measuring the voltage across the sense resistor (RS) connected from VS+ to

VS -. The required resistor value is calculated from:

(1)

where IFS is the expected full scale current range based on the current sense gain setting (GAIN). If the voltage

across RSreaches VS, the current measurement will reach the full scale measurement. As mentioned before, it is

important to limit the current to the full scale reading. While there is internal circuitry intended to maintain the

integrity of the other readings in the telemetry, the ADC and MUX are shared and overranging an input may

compromise the integrity of the other readings.

VScan be set to either 30 mV or 60 mV through software commands. This setting defaults to the sense voltage

full scale of 30 mV (GAIN = 0), or it can be set to 60 mV (GAIN = 1). The value can be set via the PMBus with

the MFR_DEVICE_SETUP (D9h) command, which defaults to the 30 mV setting. Once the current measurement

full scale is known and the VSrange is chosen, calculate the shunt based on that input voltage and maximum

current range. The maximum load current in normal operation can be used to determine the required power

rating for resistor RS.

Connections from RSto the LM25056A should be made using Kelvin techniques. In the suggested layout of

Figure 17, the small pads at the lower corners of the sense resistor connect only to the sense resistor terminals

and not to the traces carrying the high current. With this technique, only the voltage across the sense resistor is

applied to VS+ and VS-, eliminating the voltage drop across the high current solder connections.

Figure 17. Sense Resistor Connections

PC BOARD GUIDELINES

The following guidelines should be followed when designing the PC board for the LM25056A:

• Place the LM25056A close to the board’s input connector to minimize trace inductance from the connector to

following devices.

• Place a small capacitor, CIN, (0.1µF) directly adjacent to the VIN and AGND and DGND pins of the

LM25056A to help minimize transients which may occur on the input supply line. Transients of several volts

can easily occur when the load current is shut off.

• Place a 1 µF capacitor as close as possible to VREF pin.

• Place a 1 µF capacitor as close as possible to VDD pin.

• The sense resistor (RS) should be placed close to the LM25056A. In particular, the traces to the VS+, VS-,

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and VIN pins should be made as low resistance as practical to ensure maximum current and power

measurement accuracy. Connect RSusing the Kelvin techniques shown in Figure 17.

• The high current path from the board’s input to the load and the return path should be parallel and close to

each other to minimize loop inductance.

• The ground connections for the various components around the LM25056A should be connected directly to

each other, and to the LM25056A’s DGND and AGND pins, and then connected to the system ground at one

point. Do not connect the various component grounds to each other through the high current ground line. The

ground of the MMBT3904 should also be connected to the AGND pin to prevent corruption of the temperature

diode measurement.

PMBus Command Support

The device features an SMBus interface that allows the use of PMBus commands to set warn levels, error

masks, and get telemetry on VIN, VAUX, IIN, PIN, and temperature. The supported PMBus commands are shown in

Table 1.

Table 1. Supported PMBus Commands

Number Default

Code Name Function R/W Of Data Value

Bytes

03h CLEAR_FAULTS Clears the status registers and re-arms the black box Send 0

registers for updating. Byte

19h CAPABILITY Retrieves the device capability. R 1 B0h

4Fh OT_FAULT_LIMIT Retrieves or stores over temperature fault limit R/W 2 0960h

threshold.

51h OT_WARN_LIMIT Retrieves or stores over temperature warn limit R/W 2 07D0h

threshold.

57h VIN_OV_WARN_LIMIT Retrieves or stores input over-voltage warn limit R/W 2 0FFFh

threshold.

58h VIN_UV_WARN_LIMIT Retrieves or stores input under-voltage warn limit R/W 2 0000h

threshold.

78h STATUS BYTE Retrieves information about the parts operating status. R 1 01h

79h STATUS_WORD Retrieves information about the parts operating status. R 2 1001h

7Ch STATUS_INPUT Retrieves information about input status. R 1 00h

7Dh STATUS_TEMPERATURE Retrieves information about temperature status. R 1 00h

7Eh STATUS_CML Retrieves information about communications status. R 1 00h

80h STATUS_MFR_SPECIFIC Retrieves information about manufacturer specific R 1 10h

device status.

88h READ_VIN Retrieves input voltage measurement. R 2 0000h

8Dh READ_TEMPERATURE_1 Retrieves temperature measurement. R 2 0000h

99h MFR_ID Retrieves manufacturer ID in ASCII characters (NSC). R 3 4Eh

53h

43h

9Ah MFR_MODEL Retrieves Part number in ASCII characters. R 8 4Ch

(LM25056A). 4Dh

32h

35h

30h

35h

36h

00h

9Bh MFR_REVISION Retrieves part revision letter/number in ASCII (e.g., AA). R 2 41h

41h

D0h MFR_SPECIFIC_00 Retrieves auxiliary voltage measurement. R 2 0000h

MFR_READ_VAUX

D1h MFR_SPECIFIC_01 Retrieves input current measurement. R 2 0000h

MFR_READ_IIN

D2h MFR_SPECIFIC_02 Retrieves input power measurement. R 2 0000h

MFR_READ_PIN

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Table 1. Supported PMBus Commands (continued)

Number Default

Code Name Function R/W Of Data Value

Bytes

D3h MFR_SPEICIFIC_03 Retrieves or stores input current limit warn threshold. R/W 2 0FFFh

MFR_IIN_OC_WARN_LIMIT

D4h MFR_SPECIFIC_04 Retrieves or stores input power limit warn threshold. R/W 2 0FFFh

MFR_PIN_OP_WARN_LIMIT

D5h MFR_SPECIFIC_05 Retrieves maximum input power measurement. R 2 0000h

MFR_READ_PIN_PEAK

D6h MFR_SPECIFIC_06 Resets the contents of the peak input power register to Send 0

MFR_CLEAR_PIN_PEAK zero. Byte

D8h MFR_SPECIFIC_08 Retrieves or stores user SMBA fault mask. R/W 2 0000h

MFR_ALERT_MASK

D9h MFR_SPECIFIC_09 Retrieves or stores information about the LM25056A R/W 1 0000h

MFR_DEVICE_SETUP setup.

DAh MFR_SPECIFIC_10 Retrieves most recent diagnostic and telemetry R 12 0080h

MFR_BLOCK_READ information in a single transaction. 0000h

0000h

DBh MFR_SPECIFIC_11 Exponent value AVGN for number of samples to be R/W 1 00h

MFR_SAMPLES_FOR_AVG averaged, range = 00h to 0Ch .

DCh MFR_SPECIFIC_12 Retrieves averaged input voltage measurement. R 2 0000h

MFR_READ_AVG_VIN

DDh MFR_SPECIFIC_13 Retrieves averaged auxiliary voltage measurement. R 2 0000h

MFR_READ_AVG_VAUX

DEh MFR_SPECIFIC_14 Retrieves averaged input current measurement. R 2 0000h

MFR_READ_AVG_IIN

DFh MFR_SPECIFIC_15 Retrieves averaged input power measurement. R 2 0000h

MFR_READ_AVG_PIN

E0h MFR_SPECIFIC_16 Captures diagnostic and telemetry information which are R 12 0080h

MFR_BLACK_BOX_READ latched when an SMBA occurs after faults have been 0000h

cleared. 0000h

0000h

E1h MFR_SPECIFIC_17 Manufacturer-specific parallel of the STATUS_WORD to R 2 0080h

MFR_DIAGNOSTIC_WORD_READ convey all FAULT/WARN data in a single transaction.

E2h MFR_SPECIFIC_18 Retrieves most recent average telemetry and diagnostic R 12 0080h

MFR_AVG_BLOCK_READ information in a single transaction. 0000h

0000h

E3h MFR_SPECIFIC_19 Retrieves or stores auxiliary over-voltage warn limit R 2 0FFFh

MFR_VAUX_OV_WARN_LIMIT threshold.

E4h MFR_SPECIFIC_20 Retrieves or stores auxiliary under-voltage warn limit R 2 0000h

MFR_VAUX_UV_WARN_LIMIT threshold.

STANDARD PMBus Commands

CLEAR_FAULTS (03h)

The CLEAR_FAULTS command is a standard PMBus command that resets all stored warning and fault flags

and the SMBA signal. If a fault or warning condition still exists when the CLEAR_FAULTS command is issued,

the SMBA signal may not clear or will re-assert almost immediately. This command uses the PMBus send byte

protocol.

CAPABILITY (19h)

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The CAPABILITY command is a standard PMBus command that returns information about the PMBus functions

supported by the LM25056A. This command is read with the PMBus read byte protocol.

Table 2. CAPABILITY Register

Value Meaning Default

B0h Supports Packet Error Check, 400Kbits/sec, Supports SMBus B0h

Alert

OT_FAULT_LIMIT (4Fh)

The OT_FAULT_LIMIT is a standard PMBus command that allows configuring or reading the threshold for the

overtemperature fault detection. Reading and writing to this register should use the coefficients shown in the

Telemetry and Warning Conversion Coefficients Table. Accesses to this command should use the PMBus read

or write word protocol. If the measured temperature exceeds this value, an Overtemperature fault is triggered,

OT Fault flags are set and the SMBA signal is asserted.

Table 3. OT_FAULT_LIMIT Register

Value Meaning Default

0h – 0FFEh Overtemperature Fault Threshold Value 0960h

0FFFh Overtemperature Fault detection disabled n/a

OT_WARN_LIMIT (51h)

The OT_WARN_LIMIT is a standard PMBus command that allows configuring or reading the threshold for the

overtemperature warning detection. Reading and writing to this register should use the coefficients shown in the

Telemetry and Warning Conversion Coefficients Table. Accesses to this command should use the PMBus read

or write word protocol. If the measured temperature exceeds this value, an Overtemperature warning is triggered

and the OT Warning flags are set and the SMBA signal is asserted.

Table 4. OT_WARN_LIMIT Register

Value Meaning Default

0h – 0FFEh Overtemperature Warn Threshold Value 07D0h

0FFFh Overtemperature Warn detection disabled n/a

VIN_OV_WARN_LIMIT (57h)

The VIN_OV_WARN_LIMIT is a standard PMBus command that allows configuring or reading the threshold for

the VIN overvoltage warning detection. Reading and writing to this register should use the coefficients shown in

the Telemetry and Warning Conversion Coefficients Table. Accesses to this command should use the PMBus

read or write word protocol. If the measured value of VIN rises above the value in this register, VIN OV Warn

flags are set and the SMBA signal is asserted.

Table 5. VIN_OV_WARN_LIMIT Register

Value Meaning Default

0h – 0FFEh VIN Overvoltage Warning detection threshold 0FFFh (disabled)

0FFFh VIN Overvoltage Warning disabled n/a

VIN_UV_WARN_LIMIT (58h)

The VIN_UV_WARN_LIMIT is a standard PMBus command that allows configuring or reading the threshold for

the VIN undervoltage warning detection. Reading and writing to this register should use the coefficients shown in

the Telemetry and Warning Conversion Coefficients Table. Accesses to this command should use the PMBus

read or write word protocol. If the measured value of VIN falls below the value in this register, VIN UV Warn flags

are set and the SMBA signal is asserted.

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Table 6. VIN_UV_WARN_LIMIT Register

Value Meaning Default

1h – 0FFFh VIN Undervoltage Warning detection threshold 0000h (disabled)

0000h VIN Undervoltage Warning disabled n/a

STATUS_BYTE (78h)

The STATUS_BYTE is a standard PMBus command that returns the value of a number of flags indicating the

state of the LM25056A. Accesses to this command should use the PMBus read byte protocol. To clear bits in this

Table 7. STATUS_BYTE Definitions

Bit Name Meaning Default

7 BUSY Not supported 0

6 OFF Not supported 0

5 VOUT_OV Not supported 0

4 IOUT_OC Not supported 0

3 VIN_UV An input undervoltage fault has occurred 0

2 TEMPERATURE A temperature fault or warning has occurred 0

1 CML A Communication Fault has occurred 0

0 NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred 1

STATUS_WORD (79h)

The STATUS_WORD is a standard PMBus command that returns the value of a number of flags indicating the

state of the LM25056A. Accesses to this command should use the PMBus read word protocol. To clear bits in

this register, the underlying fault should be cleared and a CLEAR_FAULTS command issued. The INPUT and

VIN UV flags will default to 1 on startup.

Table 8. STATUS_WORD Definitions

Bit Name Meaning Default

15 VOUT Not supported 0

14 IOUT/POUT Not supported 0

13 INPUT An input voltage or current fault has occurred 0

12 MFR A manufacturer specific fault or warning has occurred 1

11 POWER_GOOD# Not supported 0

10 FANS Not supported 0

9 OTHER Not supported 0

8 UNKNOWN Not supported 0

7 BUSY Not supported 0

6 OFF Not supported 0

5 VOUT_OV Not supported 0

4 IOUT_OC Not supported 0

3 VIN_UV An input undervoltage fault has occurred 0

2 TEMPERATURE A temperature fault or warning has occurred 0

1 CML A communication fault has occurred 0

0 NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred 1

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STATUS_INPUT (7Ch)

The STATUS_INPUT is a standard PMBus command that returns the value of the of a number of flags related to

input voltage, current, and power. Accesses to this command should use the PMBus read byte protocol. To clear

bits in this register, the underlying fault should be cleared and a CLEAR_FAULTS command issued.

Table 9. STATUS_INPUT Definitions

Bit Name Meaning Default

7 VIN OV Fault Not supported 0

6 VIN OV Warn An input overvoltage warning has occurred 0

5 VIN UV Warn An input undervoltage warning has occurred 0

4 VIN UV Fault Not supported 0

3 Insufficient Voltage Not supported 0

2 IIN OC Fault Not supported 0

1 IIN OC Warn An input overcurrent warning has occurred 0

0 PIN OP Warn An input overpower warning has occurred 0

STATUS_TEMPERATURE (7Dh)

The STATUS TEMPERATURE is a standard PMBus command that returns the value of the of a number of flags

related to the temperature telemetry value. Accesses to this command should use the PMBus read byte protocol.

To clear bits in this register, the underlying fault should be cleared and a CLEAR_FAULTS command issued.

Table 10. STATUS_TEMPERATURE Definitions

Bit Name Meaning Default

7 OT FAULT An overtemperature fault has occurred 0

6 OT WARN An overtemperature warning has occurred 0

5 UT WARN Not supported 0

4 UT FAULT Not supported 0

3 reserved Not supported 0

2 reserved Not supported 0

1 reserved Not supported 0

0 reserved Not supported 0

STATUS_CML (7Eh)

The STATUS_CML is a standard PMBus command that returns the value of a number of flags related to

communication faults. Accesses to this command should use the PMBus read byte protocol. To clear bits in this

Table 11. STATUS_CML Definitions

Bit Meaning Default

7 Invalid or unsupported command received 0

6 Invalid or unsupported data received 0

5 Packet Error Check failed 0

4 Not supported 0

3 Not supported 0

2 Reserved 0

1 Miscellaneous communications fault has occurred 0

0 Not supported 0

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STATUS_MFR_SPECIFIC (80h)

The STATUS_MFR_SPECIFIC command, is a standard PMBus command that contains manufacturer specific

status information. Accesses to this command should use the PMBus read byte protocol. To clear bits in this

Table 12. STATUS_MFR_SPECIFIC Definitions

Bit Meaning Default

7 Not supported 0

6 Not supported 0

5 Not supported 0

4 Defaults loaded 1

3 Not supported 0

2 Not supported 0

1 A VAUX Overvoltage Warning has occurred 0

0 A VAUX Undervoltage Warning has occurred 0

READ_VIN (88h)

The READ_VIN is a standard PMBus command that returns the 12 bit measured value of the input voltage as

read from the VIN pin. Reading this register should use the coefficients shown in the Telemetry and Warning

Conversion Coefficients Table. Accesses to this command should use the PMBus read word protocol. This value

is also used internally for the VIN Over and Under Voltage Warning detection.

Table 13. READ_VIN Register

Value Meaning Default

0h – 0FFFh Measured value for VIN 0000h

READ_TEMPERATURE_1 (8Dh)

The READ_TEMPERATURE_1 is a standard PMBus command that returns the signed value of the temperature

measured by the external temperature sense diode. Reading this register should use the coefficients shown in

the Telemetry and Warning Conversion Coefficients Table. Accesses to this command should use the PMBus

read word protocol. This value is also used internally for the Over Temperature Fault and Warning detection. This

data has a range of -256°C to + 255°C after the coefficients are applied.

Table 14. READ_TEMPERATURE_1 Register

Value Meaning Default

0h – 0FFFh Measured value for TEMPERATURE 0000h

MFR_ID (99h)

The MFR_ID is a standard PMBus command that returns the identification of the manufacturer. To read the

manufacturer ID, use the PMBus block read protocol.

Table 15. MFR_ID Register

Byte Name Value

0 Number of bytes 03h

1 MFR ID-1 4Eh ‘N’

2 MFR ID-2 53h ‘S’

3 MFR ID-3 43h ‘C’

MFR_MODEL (9Ah)

The MFR_MODEL is a standard PMBus command that returns the part number of the chip. To read the

manufacturer model, use the PMBus block read protocol.

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Table 16. MFR_MODEL Register

Byte Name Value

0 Number of bytes 08h

1 MFR ID-1 4Ch ‘L’

2 MFR ID-2 4Dh ‘M’

3 MFR ID-3 32h ‘2’

4 MFR ID-4 35h ‘5’

5 MFR ID-5 30h ‘0’

6 MFR ID-6 35h ‘5’

7 MFR ID-7 36h ‘6’

8 MFR ID-8 00h

MFR_REVISION (9Bh)

The MFR_REVISION is a standard PMBus command that returns the revision level of the part. To read the

manufacturer revision, use the PMBus block read protocol.

Table 17. MFR_REVISION Register

Byte Name Value

0 Number of bytes 02h

1 MFR ID-1 41h ‘A’

2 MFR ID-2 41h ‘A’

Manufacturer Specific PMBus Commands

MFR_SPECIFIC_00: MFR_READ_VAUX (D0h)

The MFR_READ_VAUX command will report the 12-bit ADC measured auxiliary voltage. Voltages greater than

or equal to 1.199V to AGND will be reported at plus full scale (0FFFh). Voltages less than or equal to 0V

referenced to AGND will be reported as 0 (0000h). Coefficients for the VAUX value are dependent on the value

of the external divider (if used). To read data from the MFR_READ_VAUX command, use the PMBus Read Word

protocol.

Table 18. MFR_READ_VAUX Register

Value Meaning Default

0h – 0FFFh Measured value for AUX input 0000h

MFR_SPECIFIC_01: MFR_READ_IIN (D1h)

The MFR_READ_IIN command will report the 12-bit ADC measured current sense voltage. To read data from

the MFR_READ_IIN command, use the PMBus Read Word protocol. Reading this register should use the

coefficients shown in the Telemetry and Warning Conversion Coefficients Table. Please see the section on

coefficient calculations to calculate the values to use.

Table 19. MFR_READ_IIN Register

Value Meaning Default

0h – 0FFFh Measured value for input current sense voltage 0000h

MFR_SPECIFIC_02: MFR_READ_PIN (D2h)

The MFR_READ_PIN command will report the upper 12-bits of the VIN x IIN product as measured by the 12-bit

ADC. To read data from the MFR_READ_PIN command, use the PMBus Read Word protocol. Reading this

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Table 20. MFR_READ_PIN Register

Value Meaning Default

0h – 0FFFh Value for input current x input voltage 0000h

MFR_SPECIFIC_03: MFR_IIN_OC_WARN_LIMIT (D3h)

The MFR_IIN_OC_WARN_LIMIT PMBus command sets the input overcurrent warning threshold. In the event

that the input current rises above the value set in this register, the IIN Overcurrent flags are set in the status

registers and the SMBA is asserted. To access the MFR_IIN_OC_WARN_LIMIT register, use the PMBus

Read/Write Word protocol. Reading/writing to this register should use the coefficients shown in the Telemetry

and Warning Conversion Coefficients Table.

Table 21. MFR_IIN_OC_WARN_LIMIT Register

Value Meaning Default

0h – 0FFEh Value for input over current warn limit 0FFFh

0FFFh Input over current warning disabled n/a

MFR_SPECIFIC_04: MFR_PIN_OP_WARN_LIMIT (D4h)

The MFR_PIN_OP_WARN_LIMIT PMBus command sets the input overpower warning threshold. In the event

that the input power rises above the value set in this register, the PIN Overpower flags are set in the status

registers and the SMBA is asserted. To access the MFR_PIN_OP_WARN_LIMIT register, use the PMBus

Read/Write Word protocol. Reading/writing to this register should use the coefficients shown in the Telemetry

and Warning Conversion Coefficients Table.

Table 22. MFR_PIN_OP_WARN_LIMIT Register

Value Meaning Default

0h – 0FFEh Value for input over power warn limit 0FFFh

0FFFh Input over power warning disabled n/a

MFR_SPECIFIC_05: MFR_READ_PIN_PEAK (D5h)

The MFR_READ_PIN_PEAK command will report the maximum input power measured since a Power On reset

or the last MFR_CLEAR_PIN_PEAK command. To access the MFR_READ_PIN_PEAK command, use the

PMBus Read Word protocol. Use the coefficients shown in the Telemetry and Warning Conversion Coefficients

Table.

Table 23. MFR_READ_PIN_PEAK Register

Value Meaning Default

0h – 0FFEh Maximum Value for input current x input voltage since reset or 0000h

last clear

MFR_SPECIFIC_06: MFR_CLEAR_PIN_PEAK (D6h)

The MFR_CLEAR_PIN_PEAK command will clear the MFR_READ_PIN_PEAK register. This command uses the

PMBus Send Byte protocol.

MFR_SPECIFIC_08: MFR_ALERT_MASK (D8h)

The MFR_ALERT_MASK is used to mask the SMBA when a specific fault or warning has occurred. Each bit

corresponds to one of the 9 different analog and digital faults or warnings that would normally result in an SMBA

being asserted. When the corresponding bit is high, that condition will not cause the SMBA to be asserted. If that

condition occurs, the registers where that condition is captured will still be updated (STATUS registers,

MFR_DIAGNOSTIC_WORD, OT_FAULT_LIMIT). This register is accessed with the PMBus Read / Write Word

protocol.

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Table 24. MFR_ALERT_MASK Definitions

BIT NAME DEFAULT

15 VAUX UNDERVOLTAGE WARN 0

14 IIN LIMIT WARN 0

13 VIN UNDERVOLTAGE WARN 0

12 VIN OVERVOLTAGE WARN 0

11 Reserved, always set to 0 0

10 OVERTEMPERATURE WARN 0

9 VAUX OVERVOLTAGE WARN 0

8 OVERPOWER LIMIT WARN 0

7 Reserved, always set to 0 0

6 Reserved, always set to 0 0

5 Reserved, always set to 0 0

4 Reserved, always set to 0 0

3 Reserved, always set to 0 0

2 OVERTEMPERATURE FAULT 0

1 CML FAULT (Communications Fault) 0

0 Reserved, always set to 0 0

MFR_SPECIFIC_09: MFR_DEVICE_SETUP (D9h)

The MFR_DEVICE_SETUP command may be used to define operation or reset the LM25056A under host

control. This command is accessed with the PMBus read / write byte protocol.

Table 25. MFR_DEVICE_SETUP Byte Format

Bit Name Meaning

7 Reserved, always set to 0

6 Reserved, always set to 0

5 Reserved, always set to 0 GAIN = 0, Low setting (30mV)

4 Current sense gain GAIN = 1, High setting (60mV)

3 Reserved, always set to 0

2 Reserved, always set to 0

1 Reserved, always set to 0 0 = Default

0 Software reset 1 = Reset

Within this command byte, the current sense gain bit changes the range and coefficients used for current and

power measurements as well as relevant warning registers. The software reset bit is used to reset the

LM25056A. Writing a 1 to this bit will reset the device back to its default startup values.

MFR_SPECIFIC_10: MFR_BLOCK_READ (DAh)

The MFR_BLOCK_READ command concatenates the MFR_DIAGNOSTIC_WORD_READ with input telemetry

information (IIN, VAUX, VIN, PIN) as well as READ_TEMPERATURE_1 to capture all of the operating

information of the LM25056A in a single SMBus transaction. The block is 12 bytes long with telemetry

information being sent out in the same manner as if an individual READ_XXX command had been issued (shown

below). The contents of the block read register are updated every clock cycle (85 ns) as long as the SMBus

interface is idle. MFR_BLOCK_READ also specifies that the VIN, VAUX, IIN and PIN measurements are all time-

aligned whereas there is a chance they may not be if retrieved with individual PMBus commands.

The Block Read command is read via the PMBus block read protocol.

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Table 26. MFR_BLOCK_READ Register Format

Byte Count (always 12) (1 byte)

DIAGNOSTIC WORD (1 Word)

IIN_BLOCK (1 Word)

VAUX_BLOCK (1 Word)

VIN_BLOCK (1 Word)

PIN_BLOCK (1 Word)

TEMP_BLOCK (1 Word)

MFR_SPECIFIC_11: MFR_SAMPLES_FOR_AVG (DBh)

The MFR_SAMPLES_FOR AVG is a manufacturer specific command for setting the number of samples used in

computing the average values for IIN, VIN, VAUX, PIN. The decimal equivalent of the AVGN nibble is the power

of 2 samples (e.g. AVGN=12 equates to 4096 samples used in computing the average). The LM25056A supports

average numbers of 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096. The MFR_SAMPLES_FOR_AVG

number applies to average values of IIN, VIN, VAUX, PIN simultaneously. The LM25056A uses simple

averaging. This is accomplished by summing consecutive results up to the number programmed, then dividing by

the number of samples. Averaging is calculated according to the following sequence:

Y = (X(N) + X(N-1) + ... + X(0)) / N (2)

When the averaging has reached the end of a sequence (for example, 4096 samples are averaged), then a

whole new sequence begins that will require the same number of samples (in this example, 4096) to be taken

before the new average is ready.

Table 27. MFR_SAMPLES_FOR_AVERAGE

AVGN N = 2AVGN Averaging/Register Update Period

(ms)

0000 1 1

0001 2 2

0010 4 4

0011 8 8

0100 16 16

0101 32 32

0110 64 64

0111 128 128

1000 256 256

1001 512 512

1010 1024 1024

1011 2048 2048

1100 4096 4096

Note that a change in the MFR_SAMPLES_FOR_AVG register will not be reflected in the average telemetry

measurements until the present averaging interval has completed. The default setting for AVGN is 0000 and

therefore the average telemetry will mirror the instantaneous telemetry until a value higher than zero is

programmed.

The MFR_SAMPLES_FOR_AVG register is accessed via the PMBus read / write byte protocol.

Table 28. MFR_SAMPLES_FOR_AVG Register

Value Meaning Default

0h – 0Ch Exponent for number of samples to average over 00h

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MFR_SPECIFIC_12: MFR_READ_AVG_VIN (DCh)

The MFR_READ_AVG_VIN command will report the 12-bit ADC measured input average voltage. If the data is

not ready, the returned value will be the previous averaged data. However, if there is no previously averaged

data the default value (0000h) will be returned. This data is read with the PMBus Read Word protocol. This

Table 29. MFR_READ_AVG_VIN Register

Value Meaning Default

0h – 0FFFh Average of measured values for input voltage 0000h

MFR_SPECIFIC_13: MFR_READ_AVG_VAUX (DDh)

The MFR_READ_AVG_AUX command will report the 12-bit ADC measured auxiliary average voltage. If the data

is not ready, the returned value will be the previous averaged data. However, if there is no previously averaged

data the default value (0000h) will be returned. This data is read with the PMBus Read Word protocol. This

Table 30. MFR_READ_AVG_VAUX Register

Value Meaning Default

0h – 0FFFh Average of measured values for auxiliary voltage 0000h

MFR_SPECIFIC_14: MFR_READ_AVG_IIN (DEh)

The MFR_READ_AVG_IIN command will report the 12-bit ADC measured current sense average voltage. If the

data is not ready, the returned value will be the previous averaged data. However, if there is no previously

averaged data the default value (0000h) will be returned. This data is read with the PMBus Read Word protocol.

This register should use the coefficients shown in the Telemetry and Warning Conversion Coefficients Table.

Table 31. MFR_READ_AVG_IIN Register

Value Meaning Default

0h – 0FFFh Average of measured values for current sense voltage 0000h

MFR_SPECIFIC_15: MFR_READ_AVG_PIN (DFh)

The MFR_READ_AVG_PIN command will report the upper 12-bits of the average VIN x IIN product as measured

by the 12-bit ADC. If the data is not ready, the returned value will be the previous averaged data. However, if

there is no previously averaged data the default value (0000h) will be returned. This data is read with the PMBus

Read Word protocol. This register should use the coefficients shown in the Telemetry and Warning Conversion

Coefficients Table.

Table 32. MFR_READ_AVG_PIN Register

Value Meaning Default

0h – 0FFFh Average of measured value for input voltage x input current sense 0000h

voltage

MFR_SPECIFIC_16: MFR_BLACK_BOX_READ (E0h)

The MFR_BLACK_BOX_READ command retrieves the MFR_BLOCK_READ data which was latched in at the

first assertion of SMBA. It is re-armed with the CLEAR_FAULTS command. It is the same format as the

MFR_BLOCK_READ registers, the only difference being that its contents are updated with the SMBA edge

rather than the internal clock edge. This command is read with the PMBus Block Read protocol.

MFR_SPECIFIC_17: MFR_DIAGNOSTIC_WORD_READ (E1h)

The MFR_DIAGNOSTIC_WORD_READ PMBus command will report all of the LM25056A faults and warnings in

a single read operation. The standard response to the assertion of the SMBA signal of issuing multiple read

requests to various status registers can be replaced by a single word read to the

MFR_DIAGNOSTIC_WORD_READ register. The MFR_DIAGNOSTIC_WORD_READ command should be read

with the PMBus Read Word protocol. The MFR_DIAGNOSTIC_WORD_READ register is also returned in the

MFR_BLOCK_READ, MFR_BLACK_BOX_READ, and MFR_AVG_BLOCK_READ operations.

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Table 33. MFR_DIAGNOSTIC_WORD_READ Format

Bit Name Meaning Default

15 Reserved 0

14 MFR_IIN_OC_WARN or MFR_PIN_OP_WARN Input Overcurrent or Overpower Warning 0

13 VIN_UV_WARN Input Undervoltage Warning 0

12 VIN_OV_WARN Input Overvoltage Warning 0

11 Reserved 0

10 OT_WARN Overtemperature Warning 0

9 MFR_VAUX_UNDERVOLTAGE_WARN VAUX Undervoltage Warning 0

8 MFR_VAUX_OVERVOLTAGE_WARN VAUX Overvoltage Warning 0

7 CONFIG_PRESET 1

6 Reserved 0

5 Reserved 0

4 Reserved 0

3 Reserved 0

2 OT__FAULT Over Temperature Fault 0

1 CML_FAULT Communications Fault 0

0 Reserved 0

MFR_SPECIFIC_18: MFR_AVG_BLOCK_READ (E2h)

The MFR_AVG_BLOCK_READ command concatenates the DIAGNOSTIC_WORD with input average telemetry

information (IIN, VAUX, VIN, PIN) as well as TEMPERATURE to capture all of the operating information of the

part in a single PMBus transaction. The block is 12 bytes long with telemetry information being sent out in the

same manner as if an individual READ_AVG_XXX command had been issued (shown below).

AVG_BLOCK_READ also specifies that the VIN, VAUX, IIN, and PIN measurements are all time-aligned

whereas there is a chance they may not be if read with individual PMBus commands. To read data from the

AVG_BLOCK_READ command, use the SMBus Block Read protocol.

Table 34. MFR_AVG_BLOCK_READ Register Format

Byte Count (always 12) (1 byte)

DIAGNOSTIC WORD (1 word)

AVG_IIN (1 word)

AVG_VAUX (1 word)

AVG_VIN (1 word)

AVG_PIN (1 word)

TEMPERATURE (1 word)

MFR_SPECIFIC_19: VAUX_OV_WARN_LIMIT (E3h)

The VAUX_OV_WARN_LIMIT command allows configuring or reading the threshold for the VAUX overvoltage

warning detection. Reading and writing to this register should use the coefficients shown in the Telemetry and

Warning Conversion Coefficients Table. Accesses to this command should use the PMBus read or write word

protocol. If the measured value of VAUX rises above the value in this register, VAUX OV Warn flags are set and

the SMBA signal is asserted.

Table 35. VAUX_OV_WARN_LIMIT Register

Value Meaning Default

0h – 0FFEh VAUX Overvoltage Warning detection threshold 0FFFh (disabled)

0FFFh VAUX Overvoltage Warning disabled n/a

Product Folder Links: LM25056A

S/H

MUX ADC

IIN

VAUX

DIODE

READ_VIN 88h

MFR_READ_IIN D1h

MFR_READ_PIN D2h

MFR_READ_VAUX D0h

READ_TEMPERATURE_1 8Dh

VIN_UV_WARN_LIMIT 58h

VIN_OV_WARN_LIMIT 57h CMP

CMP VIN_UV WARNING

STATUS_INPUT 7Ch

STATUS_BYTE 78h

VIN_OV WARNING

STATUS_INPUT 7Ch

MFR_IIN_OC_WARN_LIMIT D3h

MFR_READ_AVG_VIN DCh

MFR_SAMPLES_FOR_AVG DBh

MFR_READ_AVG_IIN DEh

READ_AVG_PIN DFh

CMP IIN_OC WARNING

STATUS_INPUT 7Ch

MFR_PIN_OP_WARN_LIMIT D4h CMP PIN_OP WARNING

STATUS_INPUT 7Ch

MFR_VAUX_OV_WARN_LIMIT E3h

VAUX_UV WARNING

STATUS_MFR_SPECIFIC 80h

CMP OT_WARNING_LIMIT

STATUS_WORD 79h

STATUS_TEMPERATURE 7Dh

WARNING

SYSTEM

DATA

OUTPUT

WARNING

LIMITS

AVERAGED

DATA

READ_PIN_PEAK D5h

CLEAR_PIN_PEAK D6h

PEAK-HOLD

To load

PMBus Interface

READ_AVG_VAUX DDh

OT_WARNING_LIMIT 51h

VS+ VS-

VIN

CMP

OT_FAULT_LIMIT 4Fh OT_FAULT_LIMIT

STATUS_WORD 79h

STATUS_TEMPERATURE 7Dh

+12V

CMP

MFR_VAUX_UV_WARN_LIMIT E4h

VAUX_OV WARNING

STATUS_MFR_SPECIFIC 80h

MFR_DIAGNOSTIC_WORD_READ E1h

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MFR_SPECIFIC_20: VAUX_UV_WARN_LIMIT (E4h)

The VAUX_UV_WARN_LIMIT command allows configuring or reading the threshold for the VAUX undervoltage

warning detection. Reading and writing to this register should use the coefficients shown in the Telemetry and

Warning Conversion Coefficients Table. Accesses to this command should use the PMBus read or write word

protocol. If the measured value of VAUX falls below the value in this register, VAUX UV Warn flags are set and

the SMBA signal is asserted.

Table 36. VAUX_UV_WARN_LIMIT Register

Value Meaning Default

1h – 0FFFh VAUX Undervoltage Warning detection threshold 0000h (disabled)

0000h VAUX Undervoltage Warning disabled n/a

Figure 18. Command/Register and Alert Flow Diagram

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Reading and Writing Telemetry Data and Warning Thresholds

All measured telemetry data and user programmed warning thresholds are communicated in 12 bit two’s

compliment binary numbers read/written in 2 byte increments conforming to the Direct format as described in

section 8.3.3 of the PMBus Power System Management Protocol Specification 1.1 (Part II). The organization of

the bits in the telemetry or warning word is shown in Table 37, where Bit_11 is the most significant bit (MSB) and

Bit_0 is the least significant bit (LSB). The decimal equivalent of all warning and telemetry words are constrained

to be within the range of 0 to 4095, with the exception of temperature. The decimal equivalent value of the

temperature word ranges from 0 to 65535.

Table 37. Telemetry and Warning Word Format

Byte B7 B6 B5 B4 B3 B2 B1 B0

1 Bit_7 Bit_6 Bit_5 Bit_4 Bit_3 Bit_2 Bit_1 Bit_0

2 0 0 0 0 Bit_11 Bit_10 Bit_9 Bit_8

Conversion from direct format to real world dimensions of current, voltage, power, and temperature is

accomplished by determining appropriate coefficients as described in section 7.2.1 of the PMBus Power System

Management Protocol Specification 1.1 (Part II). According to this specification, the host system converts the

values received into a reading of volts, amperes, watts, or other units using the following relationship:

Where:

•X: the calculated "real world" value (volts, amps, watt, etc.)

•m: the slope coefficient

•Y: a two byte two's complement integer received from device

•b: the offset, a two byte, two's complement integer

•R: the exponent, a one byte two's complement integer

R is only necessary in systems where m is required to be an integer (for example, where m may be stored

in a register in an integrated circuit). In those cases, R only needs to be large enough to yield the desired

accuracy. (3)

Table 38. Telemetry and Warning Conversion Coefficients

Commands Condition Format Number of m b R Units

Data Bytes

READ_VIN, MFR_READ_AVG_VIN, DIRECT 2 16296 1343 -2 V

VIN_OV_WARN_LIMIT

VIN_UV_WARN_LIMIT

MFR_READ_VAUX, MFR_READ_AVG_VAUX, DIRECT 2 3416 -4 0 V

MFR_VAUX_OV_WARN_LIMIT

MFR_VAUX_UV_WARN_LIMIT

(1)MFR_READ_IIN, GAIN = 0 DIRECT 2 13797 -1833 -2 A

MFR_IIN_OC_WARN_LIMIT,

MFR_READ_AVG_IIN ,

(1)MFR_READ_IIN, GAIN = 1 DIRECT 2 6726 -537 -2 A

MFR_IIN_OC_WARN_LIMIT,

MFR_READ_AVG_IIN ,

(1)MFR_READ_PIN, GAIN = 0 DIRECT 2 5501 -2908 -3 W

MFR_PIN_OP_WARN_LIMIT,

MFR_READ_PIN_PEAK,

MFR_READ_AVG_PIN

(1)MFR_READ_PIN, GAIN = 1 DIRECT 2 26882 -5646 -4 W

MFR_PIN_OP_WARN_LIMIT,

MFR_READ_PIN_PEAK,

MFR_READ_AVG_PIN

(1) * The coefficients relating to current/power measurements and warning thresholds shown in Table 38 are normalized to a sense resistor

(RS) value of 1mΩ. In general, the current/power coefficients can be calculated using the relationships shown in Table 39.

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Table 38. Telemetry and Warning Conversion Coefficients (continued)

Commands Condition Format Number of m b R Units

Data Bytes

READ_TEMPERATURE_1, DIRECT 2 1580 -14500 -2 °C

OT_FAULT_LIMIT, OT_WARN_LIMIT

Table 39. Current and Power Telemetry and Warning Conversion Coefficients (RSin mΩ)

Commands Condition Format Number of m b R Units

Data Bytes

*MFR_READ_IIN, GAIN = 0 DIRECT 2 13797 x RS-1833 -2 A

MFR_IIN_OC_WARN_LIMIT,

MFR_READ_AVG_IIN ,

*MFR_READ_IIN, GAIN = 1 DIRECT 2 6726 x RS-537 -2 A

MFR_IIN_OC_WARN_LIMIT,

MFR_READ_AVG_IIN ,

*MFR_READ_PIN, GAIN = 0 DIRECT 2 5501 x RS-2908 -3 W

MFR_PIN_OP_WARN_LIMIT,

MFR_READ_PIN_PEAK,

MFR_READ_AVG_PIN

*MFR_READ_PIN, GAIN = 1 DIRECT 2 26882 x RS-5646 -4 W

MFR_PIN_OP_WARN_LIMIT,

MFR_READ_PIN_PEAK,

MFR_READ_AVG_PIN

Care must be taken to adjust the exponent coefficient, R, such that the values of m and b remain within the

range of -32768 to +32767. For example, if a 5 mΩsense resistor is used, the correct coefficients for the

MFR_READ_IIN command with GAIN = 0 would be m = 3363, b = -537, R = -1.

A Note on the "b" Coefficient

Since b coefficients represent offset, for simplification b is set to zero in the following discussions.

Reading Current

The current register actually displays a value equivalent to a voltage across the user specified sense resistor, RS.

The coefficients enable the data output to be converted to amps. The values shown in the example are based on

having the device programmed for a 30 mV current sense range (GAIN = 0). In the 30 mV range, the LSB value

is 7.25 µV and the full scale range is 29.68 mV. In the 60 mV current sense range (GAIN = 1), the LSB value is

14.87 µV and the full scale range in 60.88 mV.

Step Example

1. Determine full scale current and shunt value based on 29.68 mV Example: Application with 250 µΩshunt.

across shunt at full scale.Use either:

(5)

(4)

or:

2. Determine m':

(7)

(6)

3. Determine exponent R necessary to set m' to integer value m: Select R to provide integer value of m:

(8) (9)

R = -2

m = 3450

4. Final values R = -2

b = 0

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PIN = IIN x VIN

4095

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Reading Input Voltage

Coefficients for VIN are consistent between read telemetry measurements (e.g., READ_VIN, READ_AVG_VIN)

and warning thresholds (e.g., VIN_OV_WARN_LIMIT, VIN_UV_WARN_LIMIT). Input voltage values are

read/written in Direct format with 12-bit resolution and a 6.14 mV LSB. An example of calculating the PMBus

coefficients for input voltage is shown below. Reading the auxiliary voltage (e.g. MFR_READ_VAUX,

MFR_READ_AVG_VAUX) and setting the warning threshold (e.g. MFR_VAUX_UV_WARN_LIMIT) is done in

similar manner with different coefficients provided in Table 38.

Step Example

1. Determine m' based on full scale analog input and full scale digital

range: (11)

(10)

2. Determine exponent R necessary to set m' to integer value m with Select R to provide 5 digit accuracy for the integer value of m (which

desired accuracy: would be 16295 in this example):

(12) (13)

R = -2

m = 16295

3. Final values R = -2

b =0

Reading Power

The power calculation of the LM25056A is a relative power calculation meaning that full scale of the power

power register has the following relationship based on decimal equivalents of the register contents:

(14)

For this reason power coefficients will also vary depending on the shunt value and must be calculated for each

application. The power LSB will vary depending on shunt value according to 374 mW/RSfor the GAIN=1 range or

182 mW/RSfor the GAIN=0 range.

Step Example

1. Determine full scale power from known full scale of input current Example: Application with 250 µΩshunt.

and input voltage (16)

(15)

2. Determine m':

(18)

(17)

3. Optional: Determine exponent R necessary to set m' to integer Select R (in this case selected to provide 4 digit accuracy for the

value m with desired accuracy: integer value of m):

(19) (20)

R = -4

m = 13728

4. Final values R = -4

b = 0

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Determining Telemetry Coefficients Empirically with Linear Fit

The coefficients for telemetry measurements and warning thresholds presented in Table 38 are adequate for the

majority of applications. Current and power coefficients must be calculated per application as they are dependent

on the value of the sense resistor, RS, used. Table 39 provides the equations necessary for calculating the

current and power coefficients for the general case. The small signal nature of the current measurement make it

and the power measurement more susceptible to PCB parasitics than other telemetry channels. This may cause

slight variations in the optimum coefficients (m, b, R) for converting from Direct format digital values to real-world

values (e.g., amps and watts). The optimum coefficients can be determined empirically for a specific application

and PCB layout using two or more measurements of the telemetry channel of interest. The current coefficients

can be determined using the following method:

1. While the LM25056A is in normal operation measure the voltage across the sense resistor using kelvined

test points and a high accuracy DVM while controlling the load current. Record the integer value returned by

the MFR_READ_AVG_IIN command (with the MFR_SAMPLES_FOR_AVG set to a value greater than 0) for

two or more voltages across the sense resistor. For best results, the individual MFR_READ_AVG_IIN

measurements should span nearly the full scale range of the current (For example, voltage across RSof 5mV

and 20mV).

2. Convert the measured voltages to currents by dividing them by the value of RS. For best accuracy the value

of RSshould be measured. Table 40 assumes a sense resistor value of 5 mΩ.

Table 40. Measurements for linear fit determination of current coefficients:

Measured voltage across Measured Current (A) READ_AVG_IIN

RS(V) (integer value)

0.005 1 672

0.01 2 1362

0.02 4 2743

3. Using the spreadsheet or math program of your choice determine the slope and the y-intercept of the

returned by the MFR_READ_AVG_IIN command values versus the measured current. For the data shown in

Table 39:

(a) MFR_READ_AVG_IN value = slope x (Measured Current) + (y-intercept)

(b) slope = 690.4

4. To determine the ‘m’ coefficient, simply shift the decimal point of the calculated slope to arrive at at integer

with a suitable number of significant digits for accuracy (typically 4) while staying with the range of -32768 to

+32767. This shift in the decimal point equates to the ‘R’ coefficient. For the slope value shown above, the

decimal point would be shifted to the right once hence R= -1.

5. Once the ‘R’ coefficient has been determined, the ‘b’ coefficient is found by multiplying the y-intercept by 10-

R. In this case the value of b= -185.

(a) Calculated Current Coefficients:

(b) m= 6904

(d) R= -1

Where:

•X: the calculated "real world" value (volts, amps, watts, temperature)

•m: the slope coefficient, is the two byte, two's complement integer

•Y: a two byte two's complement integer received from device

•b: the offset, a two byte, two's complement integer

•R: the exponent, a one byte two's complement integer (21)

Step 5 can be repeated to determine the coefficients of any telemetry channel simply by substituting measured

current for some other parameter (e.g., power, voltage, etc.).

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Writing Telemetry Data

There are several locations that will require writing data if their optional usage is desired. Use the same

coefficients previously calculated for your application, and apply them using this method as prescribed by the

PMBus™ revision section 7.2.2 "Sending a Value"

where

•X: the calculated "real world" value (volts, amps, watts, temperature)

•m: the slope coefficient, is the two byte, two's complement integer

•Y: a two byte two's complement integer to send to the device

•b: the offset, a two byte, two's complement integer

•R: the exponent, a one byte two's complement integer (22)

PMBus Address Lines (ADR0, ADR1, ADR2)

The three address lines are to be set high (connect to VDD), low (connect to GND), or open to select one of 27

addresses for communicating with the LM25056A. These lines are read after the ENABLE pin is returned high,

and the VDD and VREF are out of a POR condition. Table 41 depicts 7-bit addresses (eighth bit is read/write

bit):

Table 41. Device Addressing

ADR2 ADR1 ADR0 Decoded Address

Z Z Z 40h

Z Z 0 41h

Z Z 1 42h

Z 0 Z 43h

Z 0 0 44h

Z 0 1 45h

Z 1 Z 46h

Z 1 0 47h

Z 1 1 10h

0 Z Z 11h

0 Z 0 12h

0 Z 1 13h

0 0 Z 14h

0 0 0 15h

0 0 1 16h

0 1 Z 17h

0 1 0 50h

0 1 1 51h

1 Z Z 52h

1 Z 0 53h

1 Z 1 54h

1 0 Z 55h

1 0 0 56h

1 0 1 57h

1 1 Z 58h

1 1 0 59h

1 1 1 5Ah

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SCL

VIH

VIL

VIH

VIL

P S S P

SDA tHD;DAT

tSU;STO

tHD;STA

tSU;STA

tSU;DAT

tHIGH

tBUF

tLOW

tRtF

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SMBus Communications Timing Requirements

Figure 19. SMBus Timing Diagram

Table 42. SMBus Timing Definition

Symbol Parameter Limits Units Comments

Min Max

fSMB SMBus Operating Frequency 10 400 kHz

tBUF Bus free time between Stop and Start Condition 1.3 µs

tHD:STA Hold time after (Repeated) Start Condition. After this 0.6 µs

period, the first clock is generated.

tSU:STA Repeated Start Condition setup time 0.6 µs

tSU:STO Stop Condition setup time 0.6 µs

tHD:DAT Data hold time 300 ns

tSU:DAT Data setup time 100 ns

tTIMEOUT Clock low time-out 25 35 ms See(1)

tLOW Clock low period 1.5 µs

tHIGH Clock high period 0.6 µs See(2)

tLOW:SEXT Cumulative clock low extend time (slave device) 25 ms See(3)

tLOW:MEXT Cumulative low extend time (master device) 10 ms See(4)

tFClock or Data Fall Time 20 300 ns See(4)(5)

tRClock or Data Rise Time 20 300 ns See(6)(5)

(1) Devices participating in a transfer will timeout when any clock low exceeds the value of tTIMEOUT,MIN of 25 ms. Devices that have

detected a timeout condition must reset the communication no later than tTIMEOUT,MAX of 35 ms. The maximum value must be adhered

to by both a master and a slave as it incorporates the cumulative stretch limit for both a master (10ms) and a slave (25ms).

(2) tHIGH MAX provides a simple method for devices to detect bus idle conditions.

(3) tLOW:SEXT is the cumulative time a slave device is allowed to extend the clock cycles in one message from the initial start to the stop. If a

slave exceeds this time, it is expected to release both its clock and data lines and reset itself.

(4) tLOW:MEXT is the cumulative time a master device is allowed to extend its clock cycles within each byte of a message as defined from

start-to-ack, ack-to-ack, or ack-to-stop.

(5) Fall time is defined as: tF= 0.9 VDD to (VILMAX – 0.15)

(6) Rise time is defined as: tR= ( VILMAX – 0.15) to (VIHMIN + 0.15)

SMBA Response

The SMBA effectively has two masks:

1. The Alert Mask Register at D8h, and

2. The ARA Automatic Mask.

Product Folder Links: LM25056A

Alert Mask D8h

From PMBus

From other

fault inputs

ARA Auto Mask

Set

Clear

Fault Condition

ARA Operation Flag Succeeded

Clear Fault Command Received

SMBAlert

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The ARA Automatic Mask is a mask that is set in response to a successful ARA read. An ARA read operation

returns the PMBus™ address of the lowest addressed part on the bus that has its SMBA asserted. A successful

ARA read means that THIS part was the one that returned its address. When a part responds to the ARA read, it

releases the SMBA signal. When the last part on the bus that has an SMBA set has successfully reported its

address, the SMBA signal will de-assert.

The way that the LM25056A releases the SMBA signal is by setting the ARA Automatic mask bit for all fault

conditions present at the time of the ARA read. All status registers will still show the fault condition, but it will not

generate and SMBA on that fault again until the ARA Automatic mask is cleared by the host issuing a Clear Fault

command to this part. This should be done as a routine part of servicing an SMBA condition on a part, even if the

ARA read is not done. Figure 20 depicts a schematic version of this flow.

Figure 20. Typical Flow Schematic for SMBA Fault

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REVISION HISTORY

Changes from Original (April 2013) to Revision A Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 32

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PACKAGE OPTION ADDENDUM

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Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM25056APSQ/NOPB NRND WQFN NHZ 24 1000 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L25056A

LM25056APSQE/NOPB NRND WQFN NHZ 24 250 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L25056A

(1) The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance

do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may

reference these types of products as "Pb-Free".

RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.

Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based

flame retardants must also meet the <=1000ppm threshold requirement.

(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation

of the previous line and the two combined represent the entire Device Marking for that device.

(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish

value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information

provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and

continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.

TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

PACKAGE OPTION ADDENDUM

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Addendum-Page 2

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

LM25056APSQ/NOPB WQFN NHZ 24 1000 178.0 12.4 4.3 5.3 1.3 8.0 12.0 Q1

LM25056APSQE/NOPB WQFN NHZ 24 250 178.0 12.4 4.3 5.3 1.3 8.0 12.0 Q1

PACKAGE MATERIALS INFORMATION

www.ti.com 30-Apr-2018

Pack Materials-Page 1

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LM25056APSQ/NOPB WQFN NHZ 24 1000 210.0 185.0 35.0

LM25056APSQE/NOPB WQFN NHZ 24 250 210.0 185.0 35.0

PACKAGE MATERIALS INFORMATION

www.ti.com 30-Apr-2018

Pack Materials-Page 2

MECHANICAL DATA

NHZ0024B

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SQA24B (Rev A)

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