发明名称 |
Wide range digital phase/frequency detector |
摘要 |
A digital phase/frequency detector circuit in a phase locked loop comprises a logic gate interconnected with a pair of bistable devices clocked respectively by input and reference digital signals to generate a square wave having a duty ratio corresponding to the phase/frequency difference between the two signals. The duty ratio of the square wave sweeps repetitively between minimum and maximum values as the phase/frequency difference changes monotonically. The square wave is integrated to obtain a repetitive sawtooth. To increase the range, circuitry is provided to provide a constant level signal when the peak of a sawtooth is approached and to reset the bistable devices to provide a multiple of the earlier range.
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申请公布号 |
US4884035(A) |
申请公布日期 |
1989.11.28 |
申请号 |
US19890351229 |
申请日期 |
1989.05.15 |
申请人 |
JOHN FLUKE MFG. CO. INC. |
发明人 |
COK, STEVEN P.;LEWANDOWSKI, ROBERT J. |
分类号 |
H03D13/00 |
主分类号 |
H03D13/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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