US Patent 10965305 Multi-phase sampling time-to-digital converter (TDC) for jitter measurement

Certain aspects are directed to a time-to-digital converter (TDC) that allows for a more accurate jitter measurement. The TDC generally includes a ring oscillator (RO) having a plurality of taps and configured to generate a plurality of RO signals at the plurality of taps, a counter having an input coupled to an oscillating node, and at least two sampling circuits, each having an input coupled to an output of the counter. In certain aspects, the at least two sampling circuits are configured to sample a count signal at the output of the counter based on at least two of the plurality of RO signals at the plurality of taps.