发明申请
- 专利标题: Phase-locked loop oscillator with counter bypass
- 专利标题(中): 带旁路的锁相环振荡器
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申请号: US10207575申请日: 2002-07-29
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公开(公告)号: US20040017263A1公开(公告)日: 2004-01-29
- 发明人: Darrell Livezey
- 主分类号: H03B005/32
- IPC分类号: H03B005/32
摘要:
A phase-locked loop circuit includes one loop for regulating phase of a VCO with respect to a reference source. In another loop, VCO frequency is compared to frequency of a crystal oscillator. Digital counters divide the frequency of the crystal oscillator and VCO to a common reference frequency. Once the frequency loop is locked, the counter at the output of the crystal oscillator is bypassed. The counter is bypassed by a flip-flop circuit clocked by the crystal oscillator and receiving a scaled input from the VCO. While the VCO frequency error is in the frequency range of correction capability of the phase-locked loop, the output of the flip-flop will duplicate the output of the counter. Thus, the counter can be bypassed and shut off.
公开/授权文献
- US06734748B2 Phase-locked loop oscillator with counter bypass 公开/授权日:2004-05-11
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