Semiconductor burn-in machine power regulator having multiple power modes

A method of operating a power regulator for a testing stage of a semiconductor burn-in board, the power regulator comprising:

• a plurality of power supplies, each power supply comprising:
• a pulse width modulator controller;
• a pulse width modulator;
• a power control circuit;
• and
• an error signal selector;
• and
• a power regulator controller,
• the method comprising:
• sending a control select signal to each of the plurality of power supplies based on a power mode using the power regulator controller;
• and
• at each power supply:
• producing a pulse width modulator control signal based on an error input using the pulse width modulator controller;
• producing a power output based on the pulse width modulator control signal using the pulse width modulator;
• outputting a measured error signal based on a difference between a measured parameter of the power output and a parameter setpoint using the power control circuit;
• and
• outputting as the error input to the pulse width modulator controller either the measured error signal or the measured error signal received from one of the other power supplies based on the control select signal using the error signal selector.