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:
Oct. 15, 1991
Filed:
Jul. 31, 1990
Krishnaswamy Nagaraj, Piscataway, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A class AB CMOS amplifier stage is disclosed having well-controlled low quiescent current and good phase stability. A first FET in a complementary push-pull output stage is driven directly by an input signal biased so that such FET conducts a small quiescent current. The second FET in the output stage is driven through a level shifting circuit. The quiescent current in the level-shifting circuit is controlled by a reference voltage. The FETs in the output stage, the level-shifting circuit and the reference-voltage generator are sized with respect to each other to determine the relative magnitudes of quiescent currents and the overall gain of the circuit. The operation of the circuit is essentially independent of process-induced variables and power-supply fluctuations. The FETs in the level-shifting stage can have relatively low impedances for good phase response property.