SDA

SCL

SMBA

VREF

DIODE

ADR0

ADR1

ADR2

VDD

DGND

AGND

VAUX

ENABLE

VIN

VS+

VS-

SMBus

Interface

MMBT3904

POL

REGULATOR

LM25056

+12V

VDD

NC

NC

LM25056

www.ti.com

SNVS784A – JANUARY 2012 – REVISED APRIL 2013

LM25056 System Power Measurement IC with PMBus

Check for Samples: LM25056

1

FEATURES

APPLICATIONS

234

•

Input Voltage Range: 3V to 17V

•

Server Backplane Systems

•

•

Base Station Power Distribution Systems

Command Structure

•

Subsystem Power Measurement

•

Remote Temperature Sensing with

Programmable Warning and Shutdown

DESCRIPTION

Thresholds

The LM25056 combines high performance analog

and digital technology with a PMBus™ compliant

•

12-bit Resolution and 1 kHz Sampling Rate

operating conditions of electrical systems including

•

True Input Power Measurement Using

computing and storage blades connected to a

backplane power bus. The LM25056 continuously

Accurately Averages Dynamic Power Readings

supplies

real-time

power,

voltage,

current,

and

temperature data to the system management host via

•

the SMBus interface.

Programmable Interval Ranging from 0.001 to

4 Seconds

The LM25056 monitoring block captures both real-

time and average values of subsystem operating

•

User Programmable WARN and FAULT

Thresholds with SMBA Notification

power.

Accurate

power

measurement

is

•

Black Box Capture of Telemetry

accomplished by measuring the product of the input

Measurements and Device Status Triggered by

voltage

and

current

through

a

shunt

resistor.

WARN and FAULT Conditions

LM25056

current

measurement

has

a

±1.5%

•

Full Featured Application Development

accuracy over the temperature range of -40°C to

Software

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

box (Telemetry/Fault Snapshot) function captures and

•

WQFN-24 Package

stores telemetry data and device status in the event

of a warning or a fault.

Typical Application Schematic

1

Please 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.

2

SMBus is a trademark of Intel Corporation.

3

PMBus is a trademark of SMIF, Incorporated.

4

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2012–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.