暗电流是影响红外探测器测量精度的重要因素之一, 暗电流的大小及波动状况主要受器件工作温度的影响。为满足器件温变速率和控温精度的要求, 采用“限斜率”和增量式PID两种不同控制算法设计高精度温度控制系统。针对半导体制冷器(TEC)低电压大电流的工作特性, 先用开关电源将输入的高电压转换为低电压, 再用多只晶体管控制多路TEC, 以达到高转换效率且输出“纯净”的目的。将该温控系统应用于某星载红外分孔径InGaAs多路探测器, 实现了在指定的时间范围内探测器温度达到稳定状态, 进入稳态后实测温度波动ΔT不大于0.02 ℃, 优于为满足仪器偏振探测精度0.2%的指标所需的温度波动ΔT不大于0.2 ℃的要求。

Dark current is one of the important factors that affect measurement accuracy of infrared detector, while the size and fluctuation of the dark current is mainly affected by the working temperature of the device.In order to meet the accuracy requirement of the temperature gradient and temperature control of device, we designed a high precision temperature control system by using two different control strategies including “limit slope” algorithm and incremental PID algorithm.Considering the operating characteristics of low voltage and large current of semiconductor cooler (TEC), we used a DC/DC convert to change the high voltage to low voltage, then used some transistors to control multi-channel TEC, in order to achieve the purpose of high conversion efficiency and get a “pure” output with low electrical noise.This temperature control system was applied to an InGaAs multi-channel detector.The result showed that:the detector temperature reached a stable state within specified time;and after entering the steady-state, temperature fluctuation ΔT is lessthan 0.02 ℃.The measurement accuracy of infrared detector can reach 0.2% as the temperature fluctuation ΔT is lessthan 0.2 ℃, so the design meets the requirement.