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:
Nov. 19, 2002
Filed:
Sep. 15, 2000
Moshe Gerstenhaber, Newton, MA (US);
Chau C. Tran, Malden, MA (US);
Mark Fazio, Winchester, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A current compensation circuit for an amplifier, for example an operational amplifier, having input and output stages coupled at a high-impedance node, compensates for any modulation of current occurring at the high-impedance node. Particularly, the compensation circuit of the present invention reduces the error current at the high-impedance node resulting from a mismatch in beta between PNP and NPN transistors in the output stage, and reduces any error current resulting from the Early voltage effects of transistors in the output stage. In this manner, the present invention serves to substantially isolate the amplifier input stage from the output load, and from any beta mismatch or Early voltage effects in the transistors of the output stage, resulting in greatly improved open-loop gain.