Patent ID: 7545193

Claim:
A voltage-controlled delay line, comprising: a delay element; and a phase interpolation circuit coupled to the delay element; wherein the delay element and the phase interpolation circuit are operative to: (i) obtain an input signal and a complement of the input signal; and (ii) use the input signal and the complement of the input signal to perform a phase interpolation process so as to realize a delay complete delay tuning range with respect to the input signal; further wherein the delay element generates a delay signal from the input signal, the delay signal being a delayed form of the input signal, and the phase interpolation circuit generates a first signal by performing a first order interpolation using the input signal and the delay signal, generates a second signal by performing a first order interpolation using the complement of the input signal and the delay signal, and generates a voltage-controlled delay line output signal by performing a second order interpolation using the first signal and the second signal.