A voltage regulator controller includes a first pin for receiving aggregate temperature information from a plurality of power stages, a plurality of second pins each for receiving phase current information from one of the power stages, control circuitry for controlling the power stages, detection circuitry for detecting signal levels at the first and second pins, and fault analysis circuitry for identifying the type of reported fault and the power stage that reported the fault based on the detected signal levels at the first and second pins and state information accessible by the controller. Aggregate temperature information is reported at the first pin in a first nominal range, and phase current information is reported at each of the second pins in a second nominal range. Each reported fault type has a unique fault signature at the first and second pins, which is outside at least one of the nominal ranges.