Time-to-voltage converter using correlated double sampling

A method comprising:

• generating a bias current;
• generating an output voltage signal that is linearly related to an input time signal based on the bias current during a first interval;
• generating a correlated reference voltage signal, generation of the correlated reference voltage signal comprising:
• sampling the bias current during a second interval to generate a bias current sample;
• and
• updating the correlated reference voltage signal using the bias current sample to generate the correlated reference voltage signal,
• wherein the first interval and the second interval are non-overlapping periodic intervals of a periodic signal.

A data converter comprising:

• a time-to-voltage converter configured to generate an output voltage signal in response to an input interval and a correlated reference voltage signal in response to a reference interval,
• wherein the data converter is a time-to-digital converter or a digital-to-time converter,
• wherein if the data converter is the time-to-digital converter, the data converter further comprises:
• a phase detector configured to generate the input interval in response to a first input signal and a second input signal;
• and
• an analog-to-digital converter configured to generate a digital code corresponding to the output voltage signal using the correlated reference voltage signal, and
• wherein if the data converter is the digital-to-time converter, the data converter further comprises:
• a digital-to-analog converter configured to use the correlated reference voltage signal to generate the input interval in response to an input digital code and an input time signal;
• and
• a comparator configured to generate an output time signal in response to a comparison of the output voltage signal and a threshold voltage level of the comparator.