Patent ID: 7904265

Claim:
A method for determining the delay of a delay element, the method comprising: applying a reference signal to a delay element and a divider, the divider generating a first modified reference signal; providing a first delay control signal at a control input of the delay element to generate a delayed signal responsive to the reference signal; comparing the modified reference signal with a time-varying voltage to generate a sample voltage; distributing a series of voltages equally separated in phase and responsive to the sample voltage to one of an integer number of outputs in accordance with the delayed signal; using the series of voltages equally separated in phase to calculate components of a first phase vector; determining a first phase measure from the first phase vector responsive to the first control input; adjusting the control input of the delay element and repeating the comparing, distributing, and using to calculate components of a second phase vector; determining a second phase measure from the second phase vector responsive to the second control input; and calculating the delay from the first phase measure and the second phase measure.