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. 11, 1992
Filed:
Dec. 05, 1991
Applicant:
Inventors:
Randal R Gingrich, Belleville, MI (US);
Nicholas L Difiore, Farmington Hills, MI (US);
Assignee:
Ford Motor Company, Dearborn, MI (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H03G / ; H03F / ;
U.S. Cl.
CPC ...
330295 ; 330-2 ; 330 84 ; 330282 ;
Abstract
A multichannel amplifier employs field-effect transistors to vary the gain of operational amplifiers in each respective channel. Gain matching of the respective channels is obtained by providing each channel with a respective DC bias voltage which compensates for differences in pinch-off voltage of the field-effect transistors. The invention permits the use of inexpensive, unmatched JFETs in the amplifier. Close gain tracking achieves very accurate stereo imaging in an audio system.