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. 15, 2000
Filed:
Dec. 31, 1998
Michael J Callahan, Jr, Austin, TX (US);
STMicrolectronics, Inc., Carrollton, TX (US);
Abstract
An integrated circuit includes a transconductance circuit having a bias current generator coupled to a power supply. The bias current generator may include a current mirror circuit having an input and an output, where a current at the output is proportional to a current at the input. A first constant current source in the transconductance circuit has a first electrode coupled to the power supply. The transconductance circuit also includes first and second transistors and a diode. The diode is forward biased by the bias current generator. The first transistor has a collector coupled to a second electrode of the first constant current source and to a signal output. The second transistor has a drain coupled to an emitter of the first transistor, a source coupled to a reference voltage and a gate coupled to a signal input. The diode has an anode coupled to a base of the first transistor and a cathode coupled to a constant voltage source. The current through the diode results in a drain-source voltage of the second transistor being constant. As a result, the transconductance circuit operation is linearized, and distortion due to drain-source voltage variation in the second transistor is reduced.