US Patent 12088303 Self-calibrated phase tuning system

A clock generation apparatus has a delay circuit, a phase selection circuit, and a phase measurement circuit. The delay circuit outputs a first signal that is a delayed version of an input signal. The phase selection circuit receives the input signal and one or more phase-shifted versions of the input signal and outputs a second signal that is a phase-shifted version of the input signal. The phase measurement circuit compares the phases of the first signal and the second signal and provides a first output that controls phase of the second signal relative to the input signal. The phase measurement circuit also provides a second output that controls a delay applied by the delay circuit to the input signal to generate the first signal.