Frequency insensitive phase detector with fast response and very low output ripple

The new phase detector circuit has fast response and almost no output ripple, approaching to the speed and ripple of the sample-hold (S/H) type detectors, while being insensitive to signal frequency as is the case with a class of “multiply and integrate” circuits. The new detector is based on simple high-pass filtration and S/H processing of the discrete signal generated in the digital part of the circuit. The response of the new phase detector is more than a hundred times faster than the response of the “multiply and integrate” class of detectors exhibiting the same output ripple. With a slight modification, the circuit can be turned into a fast frequency-to-voltage converter (FVC) with a ripple-free output