| 摘要 |
A phase locked loop for a voltage controlled oscillator includes a phase comparator receiving at its inputs a reference frequency signal and a frequency signal from the oscillator, and supplies logic values to command a charge pump. A charge re-injection circuit receives one of the inputs of the comparator and supplies a logic value to command the charge pump. The loop further includes a detector with a threshold value for a current representative of the current supplied by the charge pump. A logic output from the detector is applied to the charge re-injection circuit so that the duration of the charge re-injection is limited.
|
