Study of a New Phase Detector Based on Cmos

An analog phase discriminator, based on the two complementary CMOS switches, was proposed to measure the initial phase of the sinusoidal wave. The circuit structure of the phase discriminator and its principle were presented, and the phase computational formula was derived through a series of circuit theories. So the initial phase was acquired directly from the circuit, which covered a wide frequency range with high accuracy, controllable, stability and reliability. The effectiveness and feasibility were verified through simulation experiments at the frequency of 1.25MHz. The results show that the maximum phase error is less than 0.05 °, and the corresponding root-mean-square(RMS) value is lower than 0.2 under 256 times measurement.