Abstract: A technique for operating a common emitter circuit from a plurality of supply voltages. In one embodiment, a current mirror includes a plurality of diode-connected transistors each connected between a source of current and associated supply voltages. Corresponding current mirrors are each connected between an output terminal associated supply voltage leads, thereby providing an output current mirrored from the soure of current, regardless of which of the supply voltages are activated, and regardless of their particular levels. In another embodiment, a regulator includes an output transistor having a plurality of current handling terminals, each connected to an associated supply voltage, and a second current handling terminal coupled to an output terminal.