Phase detector circuit for periodic signal using three sampling data

Abstract From the Canadian patent

A phase detection circuit for detecting the phase shift of an input signal. An A/D converter converts the input signal into first, second and third digital data according to successive three sampling points. A first subtracter subtracts the third data from the second data to produce a first subtraction signal. A second subtracter subtracts the first data from the second data to produce a second subtraction signal. A third subtracter subtracts the second subtraction signal from the first subtraction signal to produce a signal representing the phase shift. An adder adds the first and second subtraction signals together to produce a signal representing the amplitude of the input signal. A …