在车载激光雷达系统中, 雪崩光电二级管(APD)检测微弱光信号时, 其增益和灵敏度受温度偏移影响, 导致输出信号失真, 进而影响系统测距精度、实时性与稳定性。设计了这一种带有温度控制与温度补偿功能的APD驱动电路。温度控制模块由TEC制冷器、TMP117温度传感器等器件组成。温度补偿模块采用DS1841芯片。此设计以温控为主, 温补为辅。由于TEC具有热惯性, 温控模式不能立刻使温度达到设定的目标值, 此时温补模式将被触发, 自动补偿合适的APD偏压, 达到温补目的。实验测试表明, 温控模式的控制精度为±0.3℃, 温补模式的偏压相对误差小于0.5%, 系统的测量精度与稳定性显著提高。

In an automotive lidar system, when an avalanche diode (APD) detects a weak light signal, its gain and sensitivity are affected by temperature shifts, which will cause distortion of the output signal, which will affect ranging accuracy, real-time performance and stability. This article designs this kind of APD driving circuit with temperature control and temperature compensation function. The temperature control module is composed of TEC cooler, TMP117 temperature and other devices. The temperature compensation module uses DS1841 chip. This design is based on temperature control, supplemented by temperature compensation. Due to the thermal inertia of the TEC, the temperature control mode cannot immediately bring the temperature to the set target value, and the temperature compensation mode will be triggered to automatically compensate for the appropriate APD bias to achieve the temperature compensation purpose. Through experimental tests, the control accuracy of the temperature control mode is ±0.3℃, the relative error of the bias voltage in the temperature compensation mode is less than 0.5%, and the accuracy and stability of distance measurement are significantly improved.