Abstract: A fail-safe power supply for providing operating potential to a first, e.g. drain, electrode of a device, such as a gallium-arsenide field effect transistor (GaAsFET) and the like, only if operating potential, of an opposite polarity, is previously applied to another, e.g. gate, electrode of the device. A DC-to-DC converter is powered by the gate electrode potential to provide drain electrode potential only when gate electrode is present. Both the gate and drain potentials may be electronically regulated. The DC-to-DC converter and the dual regulators may be fully integratable into a single four-lead integrated circuit.