Multi-phase clock generation employing phase error detection in a controlled delay line

Abstract

Multi-phase clock generation employing phase error detection between multiple delay circuit outputs in a controlled delay line to provide error correction is disclosed. A multi-phase clock generator is provided that includes a controlled delay line and a phase error detector circuit. Tap nodes are provided from outputs of one or more delay circuits in the controlled delay line. To detect and correct for phase errors in the controlled delay line, a phase detection circuit is provided that includes at least two phase detectors each configured to measure a phase offset error between tap nodes from the delay circuit(s) in the controlled delay line. These phase errors are then combined to create an error correction signal, which is used to control the delay of the delay circuit(s) in the controlled delay line to lock the phase of the output of the final delay circuit to an input reference clock signal.