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:
Feb. 14, 1995
Filed:
Dec. 10, 1993
Paul A Moore, Seaford, GB;
Anthony R Cusdin, Horley, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A transconductance amplifier comprises first and second input transistors having base electrodes to which an input voltage (Vi) is applied. A constant current source is connected to the emitters of the input transistors. Outputs are derived from their collector electrodes. A tapped impedance having two or more segments (R0 to RN,RN to R0) is connected between the base electrodes of the input transistors. The base electrodes of a plurality of further transistors are connected to respective taps of the tapped impedance. The emitter areas of these further transistors increase from each end of the tapped impedance towards the center of the tapped impedance. The emitters of the further transistors are connected to the current source and the collectors are connected to a junction which is connected to means for computing the combined base currents of the further transistors from the combined collector currents at said junction. The computed current is supplied by a current mirror circuit to the center of the tapped impedance to pull up the voltage at the center. The tapped impedance can have an increased resistance without unduly loading a preceding stage.