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:
Dec. 12, 1989
Filed:
Jan. 21, 1988
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A differential amplifier (10) having a circuit (18) which images or simulates the bias current flowing in an input stage (34) of the differential amplifier (10) is disclosed. This image circuit (18) resembles a differential amplifier input stage, couples to the signal inputs (28, 30) of the differential amplifier (10), and provides an output signal that reflects such bias current. One embodiment of the present invention feeds this output signal back to the differential amplifier input stage (34) to improve regulation of a constant current source (26). Another embodiment uses this signal to switch current from an external source (86) to the differential amplifier input stage (34) when a constant current source (26) within the differential amplifier input stage (34) fails to maintain a constant current supply.