A High-Resolution Calibration Method for Time-to-Digital Converter of Lidar

Abstract

High-resolution time-to-digital converter (TDC) finds major applications in light detection and ranging (Lidar) systems as one of the high precision time measuring techniques. In this work, a high-resolution TDC is designed and implemented on a Xilinx field-programmable gate array (FPGA) board. For precision time measurements, the proposed TDC uses an internal tapped delay chain written in Verilog. The TDC circuit measurement errors are examined and calibrated following several principles of error reduction techniques to meet the specific demand for the high-precision Lidar range. Experiments have shown that the suggested calibration TDC has higher performance, achieving sub-35 ps resolution. The design is fully customizable and implemented as a set of separate intellectual property cores. This allows for easy implementation and meets the requirements of the present-day pulse Lidar systems.