Low walk error multi-stage cascade comparator for TOF LiDAR application

Abstract

Aiming at the application of pulsed TOF LiDAR, this paper propose a low walk error multi-stage comparator based on the double threshold method. In order to achieve high-speed comparison output, the LVDS interface is used to output the data of the comparator. The dual-channel comparator is implemented using the SMIC 0.18 μm process which achieves a propagation delay of 620 ps and an input bandwidth of 256 MHz. Thanks to the multi-stage design, the walk error of the comparator is only 196 ps. It supports the minimum pulse width of 931 ps, the rms random jitter of 1.90 ps, and the power consumption of 39.6 mW.