Principles of the invention provide phase and frequency detectors and techniques for
generating an output signal pro portional to a frequency difference between two input
signals. Inaccordance with one embodiment of the invention, appa ratus comprises a first
circuit for receiving first and second clock signals and for generating at least one signal
indicative of a phase difference between the first and second clock signals. The apparatus
also comprises a second circuit for receiving the at least one signal generated by the first …