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. 13, 2001
Filed:
Feb. 22, 2000
James R. Hellums, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A circuit for reducing speaker “pops” and “clicks” during power on and power off transitions of an op amp driver. The circuit includes an op amp,having a first input terminal adapted to be coupled to an input signal and a second input terminal adapted to be coupled to a reference potential. A speaker,is capacitively coupled to the output terminal of the op amp,. Also included are a first current source,for coupling a first bias current to the op amp, and a second current source,for coupling a second bias current to the op amp, the first bias current being much greater than said second bias current. A switch,, coupled between the op amp,and the first current source,, is responsive to a mode control signal PWDN(bar) for enabling and inhibiting flow of the first bias current to the op amp,. In a preferred embodiment, the op amp is an integrated circuit device, and is a metal oxide semiconductor (MOS) circuit.