Sampled data amplitude linear phase detector

摘要

A sampled data phase detector is created using a differential amplifier that is provided with a feedback capacitor connected between the output and the inverting input. A reference potential is coupled to the noninverting input. A coupling capacitor is connected between the inverting input and a sampling switch that switches the coupling capacitor alternately between ground and a circuit input terminal. A second switch alternately shorts out the feedback capacitor at the clock rate during the time interval the input capacitor is grounded. In this state both inputs and the output are forced to the reference potential. On the other half of the clock cycle the amplifier input is coupled to sense the data signal. The result is a rectified version of the data signal appearing at the amplifier output. The d-c level of this signal is related to the amplitude and phase of the data signal. A full wave version of the circuit is also disclosed.