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:
May. 23, 1995
Filed:
Aug. 03, 1994
Antonius A Marinus, Eindhoven, NL;
Henricus C Buthker, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Switched-mode power supplies in which a series arrangement of a bipolar transistor and a MOS field effect transistor is used are known and referred to as cascode circuits. In these circuits the bipolar transistor is switched (with the MOS field effect transistor) via the emitter instead of with the base. Since the collector current of the bipolar transistor may vary over a large range, the base should be proportionally driven to prevent the bipolar transistor from getting either above or below its normal operating range. By making use of an extra winding on a transformer arranged in series with the cascode circuit, a non-dissipative proportional drive of the base of the bipolar transistor is obtained. The extra winding is coupled to the base via an inductance.