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:
Aug. 01, 1989
Filed:
May. 02, 1988
Michael L Low, Old Bridge, NJ (US);
Jack Craft, Bridgewater, NJ (US);
RCA Licensing Corp., Princeton, NJ (US);
Abstract
A first pair of transistors, Q721 and Q723, operating, each, as an emitter follower, has a relatively low emitter current. The emitter followers drive corresponding base electrodes of transistors of a second pair of transistors, Q148 and Q149, coupled as a differential amplifier. A current gain compensating transistor Q726 has a current gain that tracks current gain variations of each of the transistors of the second pair. A base electrode current of the compensating transistor and a second current i.sub.Q727 that is unaffected by current gain variations are summed. The summed current is coupled via transistors Q722 and Q724 of a current mirror arrangement to first and second junction terminals, 610e and 610f. The junction terminals are coupled between the respective emitter electrodes of the emitter followers and the base electrodes of the second pair. Currents generated by the current mirror arrangement compensate for variations in the base currents in the transistors of the second pair so as to maintain the emitter currents in the emitter followers substantially unaffected by these variations.