Abstract: Regulator circuits and regulation techniques that provide sufficient power for a given load requirement even where no single power supply in the system is adequate to satisfy the given load requirement. Circuits and techniques according to the invention use multiple switching regulators having inputs at different voltages and having a single combined output. A current-sense circuit allocates power provided to the output by the switching regulators such that each switching regulator provides a portion of the total output current, and therefore, power to the switching regulator.