| 摘要 |
A phase lock circuit comprising a phase frequency comparator having a first input for a reference signal and a second input for a feedback signal, as well as outputs for furnishing an up-signal or a down-signal to a control charge pump circuit, which control charge pump circuit is connected with the outputs of the phase frequency comparator and has an output which is connected via a loop filter with a voltage-controlled oscillator provided with tuning means, the output of the oscillator being connected via a frequency divider with the second input of the phase frequency comparator, while for furnishing a tuning voltage for the tuning means a voltage charge pump circuit is provided, which is combined with the control charge pump circuit to form a combined charge pump circuit connected with the output of the phase frequency comparator.
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