Design of Time-to-Digital Converter for Precision Control

摘要

The time-to-digital converter is a widely used device for measuring pulse width, timing characteristic of signal in precise control. In this paper, we present a cyclic time-to-digital converter based on the pulse-shrinking technique. Through utilizing the temperature-compensated Schmitt trigger and design rules, the time resolution of pulse-shrinking cell can be precisely adjusted by controlling the high and low threshold voltage of the transition and is low temperature-dependent as well. The proposed time-to-digital converter was implemented by TSMC 0.35μm 3.3V process and the experiment results show the time resolution error of circuit is very well under the temperature range from 20°C to 100°C. In addition, within 9ns, the differential nonlinearity (DNL) and integral nonlinearity (INL) are less than ±0.1LSB and ±0.11LSB with respect to the time resolution of 47ps.