TIME-TO-DIGITAL CONVERTER (TDC) WITH IMPROVED RESOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a time-to-digital converter (TDC) with fine resolution.SOLUTION: The TDC includes first and second delay paths 510a, b, a delay unit 520, and a phase computation unit 530. The first delay path 510a receives an input signal Sin, Sinb and a first reference signal Ref1 and provides a first output. The second delay path 510b receives an input signal Sin, Sinb and a second reference signal Ref2 and provides a second output. The delay unit 520 receives a reference signal Ref, delays the second reference signal Ref2 relative to the first reference signal Ref1 by one half inverter delay (Tinv/2), and output it. The phase computation unit 530 receives the first and second outputs and provides a phase difference between the input signal Sin, Sinb and the reference signal Ref. Calibration is performed to obtain accurate timing for the first and second delay paths 510a, b.