Patent ID: 7446693

Claim:
A method of converting an analog input voltage into a digital value comprising the steps of: converting said analog input voltage into first and second periodic signals having a phase difference there between that is a function of said analog input voltage; introducing said first periodic signal into a first end of a first consecutive series of delay elements to cause said first periodic signal to propagate through said first series of delay elements in a first direction; introducing said second periodic signal into a second end of a second consecutive series of delay elements to cause said second periodic signal to propagate through said second series of delay elements in a second direction opposite said first direction, each said delay element in said first series having a corresponding delay element in said second series, and each pair of corresponding delay elements herein termed a delay cell; determining a delay cell in which a first event in said first periodic signal meets a second event in said second periodic signal; and generating a digital value based on said determination.