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:
Mar. 07, 2000
Filed:
Jun. 15, 1998
Anthony R Bonaccio, Shelburne, VT (US);
Michel S Michail, Poughkeepsie, NY (US);
W David Pricer, Charlotte, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An operational amplifier with two differential input stages is used to separately achieve low offset voltage and broad bandwidth characteristics. One input stage addresses dc and low frequency signals while the other addresses broadband frequencies. All transistors forming the dc stage are biased in the sub-threshold region. Following the two differential input stages, the signal paths are recombined in a capacitive cross-over network that provides outputs for subsequent amplification. The cross over frequency is adjustable from 15 kHz to 50 kHz using small practical values for the cross-over capacitor. The gain balance between the two input stages is adjustable by resistors and/or predetermined width/length ratios of the operational amplifier transistors.