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:
Jun. 12, 2007
Filed:
Mar. 02, 2004
Guillaume DE Cremoux, Nijmegen, FR;
Insun Van Loo, Nijmegen, NL;
Guillaume De Cremoux, Nijmegen, FR;
Insun Van Loo, Nijmegen, NL;
NXP B.V., Eindhoven, NL;
Abstract
A three state class D amplifier () comprising a first signal path () and a second signal path (') substantially identical with the first signal path (). Each of the signal paths (′) comprises respective first and second low-pass filter means (′) coupled to respective input signals (Vn, Vp) provided by input means (Inp, In, Ip), first and second ends (A, B) of a load () and to an pulse generator () providing a signal having a frequency substantially higher than a frequency of the input signals (Vn, Vp) for generating respective first and second low-pass filtered signals (SUP, SDW). The low-pass filtered signals (SUP, SDW) are inputted to respective comparing means (′). The comparing means (′) are coupled to a threshold generator () coupled to the input means (Inp, In, Ip) and to first and second reference signals (Vmax, Vmin) representing an estimation of a maximum and a minimum signal value through the load () and generating an alternating threshold signal (THRES) that is inverse proportional to a difference between the first and second input signals (Vn, Vp) for maintaining a relative high gain of the amplifier in an idle state.