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. 30, 1999
Filed:
Nov. 03, 1998
Bing Fong Ma, Sunnyvale, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
A boost DC-DC converter with a synchronous composite rectifier is presented. The boost DC-DC converter limits inductive in-rush current, includes a shutdown mode, operates also in step-down mode, and can be fabricated using conventional bipolar processes. The composite rectifier includes a power NPN transistor and a lateral PNP transistor. During converter start-up and in step-down mode (when the output voltage is less than the input voltage), the lateral PNP transistor drives the power NPN transistor. The lateral PNP transistor is biased such that inductive volt-second balance can be maintained, limiting in-rush current. In boost mode (when the output voltage is higher than the input voltage), the lateral PNP transistor is disabled and the power transistor is driven into saturation. Again, inductive volt-second balance can be maintained.