Patent ID: 9568889
Date: 2017-02-14
CPC Classifications: G04F

Claim:
1. A time to digital converter with high resolution, comprising: a first counter, sampling an input signal according to a clock signal to calculate a first pulse width of the input signal; a reference value generator, sampling a ruler signal according to the clock signal to generate a reference value, wherein a frequency of the clock signal is greater than a frequency of the ruler signal, and the frequency of the ruler signal is greater than a frequency of the input signal; and a comparator, coupled to the first counter and the reference value generator, and comparing the first pulse width of the input signal and the reference value to generate a count result, wherein the reference value generator samples the ruler signal according to the clock signal to calculate a second pulse width of the ruler signal, and periodically latches the second pulse width according to the ruler signal to generate the reference value.