| 摘要 |
A dual-loop phase lock loop includes a phase frequency detector, a first charge pump, a second charge pump, a first capacitor, a filter, a first adder, a voltage controlled delay line, and a frequency divider. The phase frequency detector is used for outputting a switch signal according to a reference clock and a divided feedback clock. The first charge pump and the first capacitor are used for generating a coarse control voltage according to the switch signal. The second charge pump, the filter, and the first adder are used for generating a fine control voltage according to the switch signal and the coarse control voltage. The voltage controlled delay line is used for outputting a feedback clock according to the coarse control voltage and the fine control voltage. The frequency divider is used for dividing the feedback clock to output the divided feedback clock.
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