摘要 |
A phase lock circuit has a voltage tuned oscillator (VTO) which is tuned by a tuning circuit. The tuning circuit supplies tune-up and tune-down (in frequency) signals to phase lock the VTO with respect to a reference signal. The tuning circuit supplies the tune-up and tune-down signals based on the results of samples of the VTO output from a variable modulus counter (VMC) with respect to a reference signal. The reference signal and VMC are reset to a time reference by a reset generator during coarse tuning or phase locking.
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