Phase Detector. A mixer or logic circuit that compares the phase of two input signals and outputs a proportional voltage or current. It forms a core component of a phase-locked loop, taking a reference clock and a feedback signal to drive a voltage-controlled oscillator until the two inputs are perfectly aligned.
Heard on the job
If the PD output is saturated, the loop will never lock onto the reference frequency.
Also heard as
- phase detector
- phase comparator
Related terms
Phase-locked loop
A control system that generates an output signal whose phase is related to the phase of an input signal.
VCO
A voltage-controlled oscillator is a circuit that changes its output frequency based on a DC input voltage.
PLL
A phase-locked loop circuit that synchronizes an output oscillator with a reference signal.