Bipolar supply voltage generator and semiconductor device for same

Abstract

A reduced-size bipolar supply voltage generator which produces a positive and negative voltages from a unipolar power source. A single inductor is employed for current switching operation, where electric energy supplied from a power source is stored in magnetic form, and the stored magnetic energy is released as electric energy. A first and second diodes are connected to first and second ends of the inductor, respectively. The inductor is grounded at the first end via a first switch, while its second end is connected to the power source via a second switch. A switching controller activates both switches to energize the inductor. It then deactivates the first switch alone, thus directing the inductor's energy to the positive voltage output through the first diode. The controller may turn off the second switch alone after energizing the inductor. The stored energy now appears at the negative voltage output through the second diode.

Dependencies are inferred from the claim text.