Invention Grant
US08525710B1 Audio amplifier offset reduction using digital input/output comparisons
有权
使用数字输入/输出比较的音频放大器偏移量减少
- Patent Title: Audio amplifier offset reduction using digital input/output comparisons
- Patent Title (中): 使用数字输入/输出比较的音频放大器偏移量减少
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Application No.: US12750973Application Date: 2010-03-31
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Publication No.: US08525710B1Publication Date: 2013-09-03
- Inventor: Robin Matthew Tsang , Eric J. Swanson , John L. Melanson , John Christopher Tucker
- Applicant: Robin Matthew Tsang , Eric J. Swanson , John L. Melanson , John Christopher Tucker
- Applicant Address: US TX Austin
- Assignee: Cirrus Logic, Inc.
- Current Assignee: Cirrus Logic, Inc.
- Current Assignee Address: US TX Austin
- Agency: Mitch Harris, Atty at Law, LLC
- Agent Andrew Mitch Harris
- Main IPC: H03M1/06
- IPC: H03M1/06 ; H03M1/66 ; H03F99/00

Abstract:
An offset correction circuit removes DC offset from an analog audio output signal by comparing transitions of digital audio values to which the analog output signal is related to the output of a monitor that monitors the analog output signal. The monitor may be a zero-crossing detector and the transitions of the digital signal that are compared may be transitions of the most-significant bit (MSB) of the digital audio values. A filtering algorithm or filter circuit may be used to average a result of the comparison of the transitions, so that the offset is slowly and accurately removed. A chopped or autozero comparator may be used to further reduce error in the offset determination.
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