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:
Oct. 24, 1995
Filed:
Nov. 30, 1993
Richard R Garcia, Plano, TX (US);
Pradhuman S Zaveri, Plano, TX (US);
AT&T Corp., Murray Hill, NJ (US);
Abstract
A switching boost type voltage regulator includes a resonant snubber network connected in parallel with its FET power switch. The snubber includes a FET auxiliary switch that is connected and turned on in order to reduce the voltage across the FET power switch to a zero level at its turn-on transition. A driver circuit, driven by a voltage regulating pulse width modulation (PWM) pulse, initially turns on the FET auxiliary switch to reduce a voltage across the FET power switch and then turns on the FET power switch when the voltage across drops below a threshold level. The FET auxiliary switch is turned off when the FET power switch is turned on. A latch circuit insures the complimentary states of these two switches. The snubber circuit is disabled a near to zero voltage regardless of line and load levels and hence the power dissipation in the snubber is significantly reduced.