The LTC2978 is an octal, PMBus compliant power supply monitor, supervisor, sequencer and margin controller. PMBus functions include warning and fault OV/UV threshold pairs for eight output channels and one input channel. Programmable fault response allows the power supplies to be disabled with optional retry after a fault has been detected. PMBus reads allow eight output voltages and one input voltage to be monitored. In addition, odd numbered channels can substitute sense resistor voltage measurements for output voltage measurements. PMBus commands support power supply sequencing and precision point-of-load voltage servo to one of three programmed values: margin high, margin low and nominal. A programmable watchdog timer monitors microprocessor activity for a stalled condition and resets the micro if necessary. The 1-wire synchronization bus supports power supply sequencing across multiple LTC2978 devices. User programmable parameters can be stored in EEPROM. Voltage supervisor, voltage monitor and temperature faults can also be logged to EEPROM.