The LTC2970 is a dual power supply monitor and margining controller with an SMBus compatible I2C bus interface. A low-drift, on-chip reference and 14-bit A/D converter allow precise measurements of supply voltages, load currents or internal die temperature. Fault management allows ALERT to be asserted for configurable over and under voltage fault conditions. Two voltage buffered, 8-bit IDACs allow highly accurate programming of DC/DC converter output voltages. The IDACs can be configured to automatically servo the power supplies to the desired voltages using the ADC. The LTC2970-1 adds a tracking feature that can be used to turn multiple power supplies on or off in a controlled manner.