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:
Feb. 21, 1995
Filed:
Oct. 28, 1993
Brian D Meyer, Scottsdale, AZ (US);
David M Heminger, Mesa, AZ (US);
Joseph H Slaughter, III, Chandler, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
An optically isolated N-channel MOSFET driver turns on a MOSFET device in response to an optical input signal to drive a load. The turn-on time of the MOSFET is enhanced by a current boost circuit. As the MOSFET transcends to an on state and delivers current to the load, the voltage across the device diminishes and causes the current boost circuit to become inactive thus reducing to zero the current drain consumed by the current boost circuit. A photovoltaic array maintains the MOSFET operation. An optically isolated SCR is respondent to the absence of a light signal to turn off the MOSFET. Furthermore, the optical decoupling of the SCR, between the gate and source of the MOSFET device, is arranged to provide enhanced noise immunity. A voltage clamping circuit coupled between the gate and source of the MOSFET device provides additional protection to the device from large over voltages.