Design of a High-Precision Time-Domain Comparator

This paper presents a high-speed and high-precision time-domain comparator integrated circuit. The proposed comparator adopts a voltage-controlled oscillator circuit and a time amplifier, to convert the analog input voltage to a phase difference in time domain with high precision. By introducing a feedback for VCO and using the phase detector in the following stage to judge the phase differences between two signals directly, the input signals can be compared in a high speed. The comparator is designed in SMIC 0.18 μm CMOS process technology. The simulation results show that under 1 V power supply, this comparator achieves 0.1 μV accuracy, 181 MHz maximum response speed, and 86 μW power consumption.