发明授权
- 专利标题: Methods and circuits to reduce pop noise in an audio device
- 专利标题(中): 减少音频设备弹奏噪音的方法和电路
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申请号: US15057552申请日: 2016-03-01
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公开(公告)号: US09577579B2公开(公告)日: 2017-02-21
- 发明人: Ru Feng Du , Qi Yu Liu
- 申请人: STMicroelectronics (Shenzhen) R&D Co. Ltd
- 申请人地址: CN Shenzhen
- 专利权人: STMicroelectronics (Shenzhen) R&D Co. Ltd
- 当前专利权人: STMicroelectronics (Shenzhen) R&D Co. Ltd
- 当前专利权人地址: CN Shenzhen
- 代理机构: Gardere Wynne Sewell, LLP
- 优先权: CN201310422290 20130912
- 主分类号: H03F1/02
- IPC分类号: H03F1/02 ; H03F3/217 ; H03F3/21 ; H03F3/185 ; H03G3/34 ; H04R3/00 ; H03F1/30 ; H03F3/183
摘要:
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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