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:
Apr. 09, 1991
Filed:
Apr. 24, 1989
Gary V Fay, Scottsdale, AZ (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
An improved semiconductor AC switch is described having internal bias generation for the power MOSFET switches and isolated control input. Dual power MOSFETS with substrate diodes are connected in series between source and load. DC gate bias for the MOSFETS is derived from an internal power supply containing energy storage which charges from the line, typically every half cycle. The gates of the power MOSFETS are tied to the internal bias generator through a voltage divider network containing a variable resistance controlled by an optical input signal. The internal energy storage may be a capacitor or solid state battery, preferably a monolithic thick or thin film battery. No transformers or external control bias generators are required and the resulting switch is particularly simple and compact.