A power supply circuit contains a plurality of DC-DC converter control loops that provide respectively different control signals. A plurality of output driver stages of given current drive capabilities have their inputs programmably connectable via a set of switches to control signals that may be generated by any of the converter control loops. The output of each output driver stage is externally selectively connectable to any of plural output voltage ports, so that each output voltage port is capable of supplying any of the respectively different output voltages associated with the voltage control signals generated by the DC-DC converter control loops, and has an output current capability that depends upon which output driver stages are coupled to it.