Patent ID: 7166992
Filing Date: 2007-01-23
Classification: H02M,Y02B

Abstract:
1. A power supply control device which performs complementary on/off control of a first switching element and a second switching element which are coupled in series between an voltage input terminal and a reference potential terminal, allows current to flow through an inductance element coupled to a node coupling said first and second switching elements, thereby converting a voltage being applied to said voltage input terminal into a voltage which is output, includes a reverse current detection circuit to detect a reverse current state of said second switching element, and has a reverse current prevention function which prevents said second switching element from being turned on for a period during which said second switching element is to be turned on when the reverse current detection circuit detects the reverse current state, wherein said second switching element comprises a plurality of transistors coupled in parallel and the plurality of transistors are controlled so that more transistors will be kept off during a lighter load.