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:
Jun. 08, 1993
Filed:
Dec. 28, 1989
Applicant:
Inventor:
Colin Harris, New Westminster, CA;
Assignee:
Mitel Corporation, Ontario, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ; H02H / ;
U.S. Cl.
CPC ...
361 90 ; 361 56 ;
Abstract
A latchup and electrostatic discharge protection circuit for an analog reference or bias voltage power supply input connected between an input power providing terminal of the power supply and a power rail of a CMOS integrated circuit having a parasitic latch device. The protection circuit comprised of three field effect transistors close-circuits a path from the power supply input to the power rail for normal power supply conditions and open-circuits the path for excessively positive and negative voltages at the power supply input, thereby safeguarding the CMOS integrated circuit from currents resulting from the excessive positive and negative voltages.