Invention Grant
- Patent Title: Prevention of audio pop in a digital audio device
- Patent Title (中): 预防数字音频设备中的音频流行音乐
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Application No.: US12499936Application Date: 2009-07-09
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Publication No.: US08315408B2Publication Date: 2012-11-20
- Inventor: Rupinder Judge , Tie Liu , Robert Peruzzi , Richard Verney
- Applicant: Rupinder Judge , Tie Liu , Robert Peruzzi , Richard Verney
- Applicant Address: US DE Wilmington
- Assignee: Agere Systems LLC
- Current Assignee: Agere Systems LLC
- Current Assignee Address: US DE Wilmington
- Agency: Mendelsohn, Drucker & Associates, P.C.
- Agent Yuri Gruzdkov; Steve Mendelsohn
- Main IPC: H04B15/00
- IPC: H04B15/00 ; H04B27/00 ; H03F99/00 ; H02B1/00

Abstract:
An electronic audio device with a digital audio output channel in which an amplifier output voltage is gradually ramped up and down to avoid causing a popping sound when the device is turned on and off. This is accomplished without employing any additional hardware, by incrementally changing a digital input word applied to a digital audio source, such as a DSP, so as to gradually change the amplifier output voltage between a minimum, such as zero volts, and a DC working voltage. On powering up, the amplifier is only turned on after the digital word is applied, but while it still results in a minimum amplifier output, and on powering down the amplifier is turned off after it's output has been ramped down, but before removing the digital input word. Sources and output channels can also be switched over by powering down, and then powering up, following the same method.
Public/Granted literature
- US20090275322A1 PREVENTION OF AUDIO POP IN A DIGITAL AUDIO DEVICE Public/Granted day:2009-11-05
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