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. 21, 2006
Filed:
May. 14, 2004
Lars Risbo, Copenhagen, DK;
Claus N. Neesgaard, Plano, TX (US);
Lars Risbo, Copenhagen, DK;
Claus N. Neesgaard, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A class-D amplifier circuit (') providing improved open-loop error for base-band frequencies, such as the audio band, is disclosed. The amplifier circuit (′) includes a comparator () for generating a pulse-width-modulated output signal that is applied to an output power stage (). An LC filter () is at the output of the power stage (). The amplifier circuit (′) includes a loop filter having multiple feedback loop paths, with at least one feedback loop path coupled to the output of the power stage (), and optionally, at least one feedback loop path coupled to the output of the LC filter (). The transfer function (H(s)) of the loop filter has a real part that has a much steeper slope (on the order of 80 dB/decade) at frequencies above the pulse-width-modulation switching frequency than the slope of its magnitude characteristic at frequencies below this switching frequency.