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:
Feb. 05, 2002
Filed:
Mar. 16, 2000
John Laurence Melanson, Austin, TX (US);
Audio Logic, Inc., Boulder, CO (US);
Abstract
The digital amplifier of the present invention comprises a delta sigma noise shaper feeding a pulse wave modulator (PWM) which drives a load such as a speaker. The amplifier includes circuitry to measure the voltage coming out of the power supply in the circuit, and using this measurement as a control signal to modify the feedback path and direct path of the noise shaper, in order to correct the pulse width output to compensate for the varying power supply voltages. The amplifier may also include circuitry to correct for the nonlinear effects of pulse wave modulation, by correcting the feedback applied to one stage of the noise shaper such that it is nontrivially different from the feedback applied to another stage.