An "absolute" delay regulator of a clock repeater chip performs a precise measurement of the propagation delay of a clock signal and adjusts that delay so as to maintain a fixed-phase relationship with an input clock signal. A replica loop accurately replicates the internal path and external loading,...http://www.google.com/patents/US5309035?utm_source=gb-gplus-sharePatent US5309035 - Method and apparatus for clock skew reduction through absolute delay regulation
