Patent ID: 6959016

Claim:
A variable delay circuit comprising: a fine delay circuit receiving a clock signal and generating a delayed clock signal, the delayed clock signal having a delay relative to the clock signal that corresponds to a fine delay control signal applied to a control input of the fine delay circuit, the delay corresponding to the fine delay control signal being greater than a predetermined minimum delay and less than a predetermined maximum delay; a coarse delay circuit controlling timing of a digital signal relative to the clock signal in delay increments responsive to a coarse delay control signal applied to a control input of the coarse delay circuit; and a control circuit receiving a signal indicative of the delay of the fine delay circuit, the control circuit generating the coarse delay control signal to change the timing of the digital signal in one direction responsive to the delay of the fine delay circuit being within a predetermined range of the predetermined minimum delay, the control circuit generating the coarse delay control signal to change the timing of the digital signal in the opposite direction responsive to the delay of the fine delay circuit being within a predetermined range of the predetermined maximum delay.