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:
Sep. 12, 2000
Filed:
May. 09, 1997
John A Fifield, Underhill, VT (US);
Lawrence G Heller, South Burlington, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A self biased differential amplifier has a switching point accurately set according to a reference voltage. DC hysteresis is provided, by a circuit internal to the differential amplifier. The amplifier has an input circuit having first and second series connected transistors, wherein the beta ratio of these first and second transistors is changed by enabling an additional transistor of a hysteresis circuit according to an output state of the differential amplifier. When the output state is 'high', the switching point is decreased in order that temporary small drops (due to noise or glitches) in the input signal are ignored. Conversely, when the output state is 'low', the switching point is increased in order that temporary small increases in the input signal are ignored.