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.

Date of Patent:
Feb. 21, 2017

Filed:

Mar. 01, 2016
Applicant:

Stmicroelectronics (Shenzhen) R&d Co. Ltd, Shenzhen, CN;

Inventors:

Ru Feng Du, Shenzhen, CN;

Qi Yu Liu, Shenzhen, CN;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 1/02 (2006.01); H03F 3/217 (2006.01); H03F 3/21 (2006.01); H03F 3/185 (2006.01); H03G 3/34 (2006.01); H04R 3/00 (2006.01); H03F 1/30 (2006.01); H03F 3/183 (2006.01);
U.S. Cl.
CPC ...
H03F 1/0205 (2013.01); H03F 1/305 (2013.01); H03F 3/183 (2013.01); H03F 3/185 (2013.01); H03F 3/211 (2013.01); H03F 3/2171 (2013.01); H03F 3/2173 (2013.01); H03G 3/348 (2013.01); H04R 3/002 (2013.01); H03F 2200/03 (2013.01); H03F 2200/351 (2013.01); H03F 2203/21106 (2013.01);
Abstract

A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.


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