Patent ID: 7272200
Filing Date: 2007-09-18
Classification: H03K,H04L

Abstract:
1. A phase shifter for shifting a phase relation between a clock signal and a data signal, the phase shifter comprising: a first filter that inputs at least one of the clock signal and the data signal to be phase-shifted; a first signal path and a second signal path that divide an output signal from the first filter to input divided signals; a phase shift element that gives different phases to one of the divided signals on the first signal path and another of the divided signals on the second signal path; a first variable gain amplifier located on the first signal path; a second variable gain amplifier located on the second signal path; an adder-subtractor that executes an operation to an output from the first variable gain amplifier and an output from the second variable gain amplifier; a second filter that inputs an output from the adder-subtractor; and control means that adjusts at least one output of the first and second variable gain amplifiers to thereby adjust the phase of the output from the second filter.