Patent ID: 6351153
Filing Date: 2002-02-26
Classification: H03D,H03L

Abstract:
A phase detector with high precision, comprising:a first input, wherein the first input has a high level and a low level; a second input, wherein the second input has a high level and a low level; a first circuitry that delays the second input and transmits a delayed second input; a first XOR gate that performs an exclusive OR operation on the first input and the delayed second input to produce a first output; a second circuitry that delays and inverts the second input and transmits a delayed, inverted second input; a second XOR gate that performs an exclusive OR operation on the first input and the delayed, inverted second input to produce a second output; and a differential amplifier that subtracts the second output from the first output to produce a phase indicating voltage, wherein the phase indicating voltage is at a maximum when the first input and the second input are zero degrees out of phase and the phase indicating voltage is at a minimum when the first input and the second input are one-hundred eighty degrees out of phase.