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:
Aug. 22, 1989
Filed:
Jan. 30, 1989
Douglas B Osborn, Kokomo, IN (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
A snubber circuit comprising two stages regulates the gate current of a MOSFET in relation to the drain voltage at turnoff to clamp transient inductive voltages to a nondestructive level. At the onset of the turnoff, a current source is activated to discharge the gate capacitance, and the snubber controls the magnitude of such current in relation to the sensed drain voltage to stabilize the drain voltage at a nondestructive level. When the drain voltage approaches its limit value, a current injection circuit supplies additional current to the gate to sustain the MOSFET conduction, again in relation to the sensed drain voltage. When the inductive energy stored in the load is substantially dissipated, the drain voltage falls; at such point, the current injection circuit is disabled and the conduction of the current source is increased to complete the turnoff of the MOSFET.