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. 10, 1999
Filed:
Aug. 04, 1997
Hajime Andoh, Shiga, JP;
Denny Duan Tang, Saratoga, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A low-power dual-g.sub.m differential operational transconductance amplifier (OTA) having a differential input for improved common-mode noise rejection, a high transconductance for power savings, and circuitry for controlling its output conductance. The OTA includes a pair of input inverters for receiving differential input signals, a common-mode voltage control circuit for controlling the DC voltage levels of the inverters, and a Q-control circuit for adjusting the OTA's output conductance. The common-mode voltage control circuit has a pair of compensating current sources and a feedback loop acting as a high-gain amplifier. The high-gain amplifier has a pair of comparators for respectively comparing the DC voltage levels of the inverter outputs with a reference voltage. The Q-control circuit includes a current source coupled to a crossed-coupled NMOS transistor pair such that the OTA's output conductance may be controlled by adjusting the current source.