PHASE FREQUENCY DETECTOR HAVING INSTANTANEOUS PHASE DIFFERENCE OUTPUT

摘要

A phase frequency detector comprises means for providing Up/Down signals in order to detect a phase difference between detector input signals, and output control means having Up/Down signal inputs for providing a detector output signal containing a measure which is proportional to said detected phase difference, and having capacitor means for providing the detector output signal whose measure depends instantaneously on said detected phase difference. This allows a loop filter which is present in a phase locked loop to have reduced averaging properties and to have a broader bandwidth resulting in a cleaner output frequency signal of a voltage controlled oscillator in the phase locked loop.