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:
Apr. 29, 2003
Filed:
Nov. 27, 2001
John M. Muza, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A single-ended, ultra low voltage class AB power amplifier ( ) including an input gain stage ( ), output gain stage ( ), a quiescent current control circuit ( ) and a output stage bias reference circuit ( ). The input gain stage ( ) includes differential inputs (IN , IN ) and differential outputs (A , B ). The output stage ( ), having control transistors, connects to each differential output (A , B ) of the input stage ( ). and a quiescent current control circuit ( ) deriving common mode feedback control signal (V ) from the differential outputs (A , B ) and voltage bias node (D ). A quiescent current control circuit ( ) derives the common mode feedback control signal (V ) to maintain the voltage of the input gain stage transistors (M , M ) at a desired level. The quiescent current control circuit ( ) uses the bias voltage (V ) supplied by an output stage bias reference ( ) coupled thereto for generating the control signal (V ) to be applied to the gates of the input stage transistors (M , M ), thereby maintaining the quiescent current of the output transistors (M , M ) at a desired value.