Invention Grant
- Patent Title: Methods and circuits to reduce pop noise in an audio device
- Patent Title (中): 减少音频设备弹奏噪音的方法和电路
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Application No.: US14478531Application Date: 2014-09-05
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Publication No.: US09306523B2Publication Date: 2016-04-05
- Inventor: Ru Feng Du , Qi Yu Liu
- Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd.
- Applicant Address: CN Shenzhen
- Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
- Current Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
- Current Assignee Address: CN Shenzhen
- Agency: Gardere Wynne Sewell LLP
- Priority: CN201310422290 20130912
- Main IPC: H04R3/00
- IPC: H04R3/00 ; H03G3/34

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.
Public/Granted literature
- US20150071464A1 METHODS AND CIRCUITS TO REDUCE POP NOISE IN AN AUDIO DEVICE Public/Granted day:2015-03-12
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