Patent ID: 8008954
Filing Date: 2011-08-30
Classification: G06F,G11C,H03L

Abstract:
1. A multi-phase periodic signal generator comprising: a plurality of delay elements including a first delay element, an intermediate delay element, and a third delay element, each of the first and second delay elements coupled such that an output of a respective delay element is coupled to an input of a next delay element, each of the respective delay elements configured to delay a signal applied to an input of the respective delay element and couple the delayed signal to the respective next delay element, the first delay element configured to receive a first periodic signal, the intermediate delay element configured to output an intermediate periodic signal, and the third delay element configured to output a third signal; a phase detector configured to receive the first signal, the third signal, and the intermediate signal, the phase detector configured to be enabled responsive to the intermediate signal and when enabled to provide a signal indicative of a phase difference between the first and third signals; a control signal generator configured to receive the signal indicative of the phase difference between the first and third signals and generate a control signal to adjust the delay of the plurality of delay elements such that the first, intermediate and third signals have a predetermined phase relationship; and a duty cycle distortion tolerance delay element configured to receive the first signal and the third signal, the duty cycle distortion tolerance delay element configured to delay the respective first and third signals and output the delayed first and third signals to the phase detector.