1FEATURES
234• Input Voltage Range: 3V to 17V
• I2C/SMBus Interface with PMBus Compliant
Command Structure
• Remote Temperature Sensing with
Programmable Warning and Shutdown
Thresholds
• Real Time Monitoring of VIN, IIN, PIN, VAUX with
12-bit Resolution and 1 kHz Sampling Rate
• Current Measurement Error: ±0.5%: +10°C to
+85°C
• Voltage Measurement Error: ±1.0%: +10°C
to+85°C
• Power Measurement Error: ±1.5%: +10°C to
+85°C real•
True Input Power Measurement Using
Simultaneous Sampling of V IN and IIN Accurately Averages Dynamic Power Readings
• Averaging of VIN, IIN, PIN, and VAUX Over
Programmable Interval Ranging from 0.001 to
4 Seconds
• User Programmable WARN and FAULT
Thresholds with SMBA Notification
• Black Box Capture of Telemetry
Measurements and Device Status Triggered by
WARN and FAULT Conditions
• Full Featured Application Development
Software
• WQFN-24 Package

APPLICATIONS
• Server Backplane Systems
• Base Station Power Distribution Systems
• Subsystem Power Measurement

DESCRIPTION
The LM25056A combines high performance analog
and digital technology with a PMBus™ compliant
SMBus™/I2C interface to accurately measure the
operating conditions of electrical systems including
computing and storage blades connected to a
backplane power bus. The LM25056A continuously
supplies real-time power, voltage, current, and
temperature data to the system management host via
the SMBus interface.
The LM25056A monitoring block captures both real•
time and average values of subsystem operating
parameters (VIN, IIN, PIN, VAUX) as well as peak
power. Accurate power measurement is
accomplished by measuring the product of the input
voltage and current through a shunt resistor.
LM25056A current measurement has a ±0.5%
accuracy over the temperature range of +10°C to
+85°C with operation from -40°C to +125°C. A black
box (Telemetry/Fault Snapshot) function captures and
stores telemetry data and device status in the event
of a warning or a fault.