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:
Jan. 31, 2012
Filed:
Sep. 09, 2009
Shu Hung Chung, Hong Kong, HK;
Tin Ho LI, Kowloon, HK;
Shu Hung Chung, Hong Kong, HK;
Tin Ho Li, Kowloon, HK;
City University of Hong Kong, Hong Kong, HK;
Abstract
A passive lossless snubber cell for a switched-mode power converter comprises an energy absorbing circuit and an energy resetting circuit coupled to said energy absorbing circuit. The energy absorbing circuit is arranged to release energy stored in a snubber capacitor of the energy absorbing circuit to a storage capacitor of the energy resetting circuit through a resonant pathway of the snubber cell in response to a first switching action of a power converter transistor switch. The energy resetting circuit is arranged to release the energy stored therein to a part of a circuit of the power converter in response to a second switching action of the power converter transistor switch, the second switching action being a successive action to the first switching action. The passive lossless snubber cell has several advantages over existing snubbering techniques. First, it provides zero-current-switching (ZCS) and zero-voltage-switching (ZVS) conditions for turning on and off, respectively, the switch over a wide load range. Second, it does not introduce extra voltage stress on the switch. Third, by taking the ripple current through the switch into account, the peak switch current during the snubber resonance period is designed to be less than the designed switch current without the snubber. Hence, the proposed snubber does not introduce extra current stress on the switch.