Abstract: A high gain digital phase comparator which in digital phase lock loop systems can give a thousand-fold reduction in ripple and close-in noise sideband amplitudes. The comparator is of the sample-and-hold type but the normal ramp reference waveform is replaced by a trapezoidal waveform with a very steep rising or falling slope generated by a trapezoidal waveform generator. This slope is sampled by a sampling circuit coupled to said generator and its steepness gives the increased gain of the phase comparator leading to the reduced noise and ripple. Additional logic and switching circuits are added to make the comparator operate only during a rising edge of the trapezoidal waveform.