4-Channel PMBus Power System Manager Featuring Accurate Input Current and Energy Measurement
The LTC®2975 is a 4-channel Power System Manager used to sequence, trim (servo), margin, supervise, manage faults, provide telemetry and create fault logs.
PMBus commands support power supply sequencing, precision point-of-load voltage adjustment and margining. DACs use a proprietary soft-connect algorithm to minimize supply disturbances. Supervisory functions include over and under current, voltage and temperature threshold limits for four power supply output channels as well as over and under voltage threshold limits for a single power supply input channel. Programmable fault responses can disable the power supplies with optional retry after a fault is detected. Faults that disable a power supply can automatically trigger black box EEPROM storage of fault status and associated telemetry.
An internal 16-bit ADC monitors four output voltages, four output currents, four external temperatures, input voltage and current, and die temperature. Input power, energy, and output power is also calculated. A programmable watchdog timer monitors microprocessor activity for a stalled condition and resets the microprocessor if necessary.
A single wire bus synchronizes power supplies across multiple LTC Power System Management (PSM) devices. Configuration EEPROM supports autonomous operation without additional software.
Applications
- Computers and Network Servers
- Industrial Test and Measurement
- High Reliability Systems
- Video and Medical Imaging

Features
Order Custom Programmed Parts
Sequence, Trim, Margin and Supervise Four Power Supplies
Manage Faults, Monitor Telemetry and Create Fault Logs
PMBus™ Compliant Command Set
Supported by LTpowerPlay™ GUI
Margin or Trim Supplies to Within 0.25% of Target
Monitor Input Current (±1%) and Accumulate Energy
Fast OV/UV and OC Supervisors Per Channel
Coordinate Sequencing and Fault Management Across Multiple LTC PSM Devices
Automatic Fault Logging to Internal EEPROM
Operate Autonomously Without Additional Software
External Temperature and Input Voltage Supervisors
Accurate Monitoring of Four Output Voltages, Four Output Currents, Four External Temperatures, Input Voltage and Current, and Internal Die Temperature
I2C/SMBus Serial Interface
Can Be Powered from 3.3V, or 4.5V to 15V
Pin-Compatible to the LTC2974
Available in 64-Lead 9mm × 9mm QFN Package