发明申请
- 专利标题: Loop filter for class D amplifiers
- 专利标题(中): D类放大器的环路滤波器
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申请号: US10846281申请日: 2004-05-14
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公开(公告)号: US20050017799A1公开(公告)日: 2005-01-27
- 发明人: Lars Risbo , Claus Neesgaard
- 申请人: Lars Risbo , Claus Neesgaard
- 申请人地址: US TX Dallas
- 专利权人: Texas Instruments Incorporated
- 当前专利权人: Texas Instruments Incorporated
- 当前专利权人地址: US TX Dallas
- 主分类号: H03F3/217
- IPC分类号: H03F3/217 ; H03F3/38
摘要:
A class-D amplifier circuit (30; 30′) providing improved open-loop error for base-band frequencies, such as the audio band, is disclosed. The amplifier circuit (30; 30′) includes a comparator (35) for generating a pulse-width-modulated output signal that is applied to an output power stage (37). An LC filter (32) is at the output of the power stage (37). The amplifier circuit (30; 30′) includes a loop filter having multiple feedback loop paths, with at least one feedback loop path coupled to the output of the power stage (37), and optionally, at least one feedback loop path coupled to the output of the LC filter (32). The transfer function (Hmae(s)) of the loop filter has a real part that has a much steeper slope (on the order of 80 dB/decade) at frequencies above the pulse-width-modulation switching frequency than the slope of its magnitude characteristic at frequencies below this switching frequency.
公开/授权文献
- US07002406B2 Loop filter for class D amplifiers 公开/授权日:2006-02-21
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