Patent ID: 6956420

Claim:
An apparatus, comprising: an inverting first matching stage responsive to an input clock signal to generate a first inverted signal having a first matching delay, the first matching delay being a difference between a first rise and a first fall propagation time of the inverting first matching stage; an inverting first pull-up stage coupled to the inverting first matching stage and responsive to the first inverted signal to generate a second inverted signal having a first pull-up delay which is substantially equal to the first matching delay, the first pull-up delay being a difference between a second rise and a second fall propagation time of the inverting first pull-up stage; an inverting first output stage coupled to the inverting first pull-up stage to generate a third inverted signal in response to the second inverted signal; and the first pull-up stage being configured to generate a variable phase delay in the second inverted signal and the third inverted signal.