Patent ID: 8390349

Claim:
A time-to-digital converter (TDC) comprising: a voltage controlled oscillator (VCO/DCO) to output a VCO/DCO signal; a delay module configured to store, in a plurality of latches, samples of the VCO/DCO signal clocked by a periodic ring oscillator signal, wherein each latch is configured to generate an output of the sample, and each latch output represents an encoding of the quantized time difference between the VCO/DCO signal and the periodic ring oscillator signal; and a plurality of decision units, some decision unit having first and second input ports and an output port providing an output signal, each first input port of the plurality of decision units connected to the VCO/DCO signal and each second input port of the plurality of decision units connected to the ring oscillator signal, wherein the output signal is indicative of time difference between the VCO/DCO signal and the ring oscillator signal; wherein the outputs from the delay module and the plurality of decision units are combined to provide a high resolution output.