The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 1997
Filed:
May. 22, 1996
Tetushi Otake, Tokyo, JP;
Toko, Inc., Tokyo, JP;
Abstract
A switching power supply in which high efficiency is obtained by further reducing a loss occurring in a PNP type transistor as a rectifying element, particularly in case of making a switching frequency higher. Further, the switching power supply is a boost/buck converter in which an application range of an input voltage is broadened by causing a circuit not to perform intermittent operation when the voltage V.sub.IN is higher than an output voltage V.sub.o. One end of a choke coil L1 is connected to an input terminal 1 and another end thereof is connected to an emitter of a PNP type transistor Q2 as a rectifying element. A base of transistor Q2 is connected to a collector of a driving transistor Q3 via a resistor R4. The base of the driving transistor Q3 is connected to another end of the choke coil L1 via a series circuit of a capacitor C3 and a resistor R3. Further, the base of the transistor Q2 is connected to one end of the input terminal side of the choke coil via an auxiliary bias circuit 4 or an impedance circuit 5.