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. 29, 2006
Filed:
May. 15, 2001
Brian A. Baker, Raleigh, NC (US);
Mark A. Casparian, Raleigh, NC (US);
Kenneth S. Seethaler, Raleigh, NC (US);
Gregory J. Zandt, Semora, NC (US);
Brian A. Baker, Raleigh, NC (US);
Mark A. Casparian, Raleigh, NC (US);
Kenneth S. Seethaler, Raleigh, NC (US);
Gregory J. Zandt, Semora, NC (US);
Lenovo (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A method of powering an audio output device of a computer system, by determining whether a passive or active audio output device is connected to an audio output jack of the computer system and, based on this determination, providing an appropriate power level to the audio output jack. For example, if the determination is made that a passive audio output device is connected to the audio output jack, then a 3-watt power signal is applied to the audio output jack, but if the determination is made that an active audio output device is connected to the audio output jack, then a ¼-watt power signal is applied to the audio output jack. The type of audio output device present may be determined by sensing an impedance at the audio output jack. This sensing may be performed by comparing a load voltage associated with the impedance to a reference voltage. The output of a switch device (multiplexer) having a first input from an AC97 audio codec and headphone amplifier and a second input from a passive speaker amplifier is selectively controlled by the sensing circuit.