Design of dynamic range adjustable laser ranging chip based on element sharing

Abstract

This work proposes a design of a dynamic range adjustable laser ranging chip based on element sharing, which combines single photon avalanche diodes and direct time-of-flight (dToF) to address the uncertainty of detection distance in different usage scenarios of laser ranging technology. To achieve adjustable dynamic range of the chip, an element shared control logic circuit based on external control signals is designed and integrated, which can adjust the measurement dynamic range of the chip through external control signals, making it suitable for different usage scenarios. Moreover, when the dynamic range of the chip changes, the measurement resolution of the time-to-digital converter (TDC) in the chip can remain unchanged. Through the analysis of simulation results, it is found that the laser ranging chip designed in this work can adjust the dynamic range from 3 ns to 4.29 s based on external control signals at a resolution of 125 ps, with a reference clock signal input frequency of 20 MHz. The differential non-linearity (DNL) error of TDC is −0.22 LSB to 0.19 LSB, and the integral non-linearity (INL) error is −0.82 LSB to 0.52 LSB. The dynamic range adjustable laser ranging chip based on element sharing designed in this work provides a feasible solution to address the uncertainty of detection distance in laser ranging technology.