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. 06, 2002
Filed:
Jul. 06, 2000
Applicant:
Inventor:
Thomas Joseph O'Brien, Limerick, PA (US);
Assignee:
STMicroelectronics, Inc., Carrollton, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 3/38 ;
U.S. Cl.
CPC ...
H03F 3/38 ;
Abstract
The invention provides a method and apparatus for the modulation of more than one channel of audio in a digital amplification system. In the preferred embodiment of the invention, pulse width modulator outputs are staggered in time such that at idle only one channel switches states at a time. This is done to provide an even draw from the power supply, assuming that the same supply is used for the multiple channels. For example, in a two channel system, the idle state of the pulse width modulator for the first channel is 90 degrees out of phase with the pulse width modulator output of the second channel.