Four-Channel PMBus Power System Manager with Input Energy Monitoring for Comprehensive Power System Management

Systems with multiple power rails are becoming more efficient, but increasingly complex and difficult to design. In such systems, operating costs and complexity have shifted the power system design paradigm. To adapt, groups of power supplies need to be controlled and monitored to manage efficiency, to coordinate sequencing, and to measure power and energy consumption. Wide supply tolerances force higher average supply voltages, increasing energy consumption. Unmonitored supply rails make inefficiencies difficult to find. When something goes wrong in a complex power system, it can be very difficult to identify root cause and correct the problem. Our Power System Managers trim supplies to improve efficiency, monitor supply rails to help identify inefficiencies, and supervise voltages, currents and temperatures. For abnormal events, faults are generated and relevant system information is stored to an EEPROM fault log to help with system debug.

The LTC2975 is a four-channel PMBus Power System Manager with input energy monitoring for comprehensive power system management. It belongs to a family of Power System Management (PSM) devices designed to transform virtually any group of DC/DC converters, LDOs and regulators into a high performance power supply system controlled and monitored by PMBus compliant commands over an I2C/SMBus digital serial interface. As a Power System Manager, the LTC2975 turns four output supply rails into a managed power system capable of trimming each rail to within 0.25% of target, sequencing supplies, supervising the supply outputs while managing any faults, and monitoring telemetry data from accurate output voltage, current, and temperature measurements. The LTC2975 also adds 4.5V to 15V intermediate bus input voltage, current, power and energy measurement read-back to the product family’s capabilities.