发明授权
- 专利标题: Dual-loop phase-locked loop
- 专利标题(中): 双回路锁相环
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申请号: US969100申请日: 1997-11-13
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公开(公告)号: US5854575A公开(公告)日: 1998-12-29
- 发明人: Alan S. Fiedler , Daniel J. Baxter
- 申请人: Alan S. Fiedler , Daniel J. Baxter
- 申请人地址: CA Milpitas
- 专利权人: LSI Logic Corporation
- 当前专利权人: LSI Logic Corporation
- 当前专利权人地址: CA Milpitas
- 主分类号: H03L7/093
- IPC分类号: H03L7/093 ; H03L7/107 ; H03L7/08
摘要:
An integrated circuit phase-locked loop includes a phase/frequency detector, a charge pump, and a voltage-controlled oscillator (VCO) which are coupled together in series. The VCO has first and second VCO control inputs, and has a VCO output which is coupled to the phase/frequency detector. An off-chip loop filter input is coupled between the charge pump and the first VCO control input for coupling to an off-chip loop filter. An on-chip loop filter is coupled between the first VCO control input and the second VCO control input. The VCO has a lower voltage-to-frequency gain from the first VCO control input to the VCO output than from the second VCO control input to the VCO output.
公开/授权文献
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