光导探测器阵列分时供电电路的实验验证

Experimental Verification for Time Division Current Driving Circuit of Photoconductive Sensor Array

为解决光导探测器阵列测量电路自身发热引起的温升过高和信号基线漂移问题,提出采用分时恒流驱动的方案。通过用16只精密电阻代替电桥式测量单元,构建了简化的16路分时恒流供电的验证实验电路,实验获得的16个输出电压与采用的电阻值呈线性关系,输出电压拟合直线斜率等于恒流源的输出电流。通过设计适当的低通滤波器,消除了因开关切换引起的毛刺,获得了理想的输出波形,证明了对多通道光导探测阵列进行分时恒流供电的方案是切实可行的。

A project adopting time division constant current to drive photoconductive sensor array was proposed to eliminate baseline drifts by sharply reducing the heat dissipation from the measure- ment circuit. A simplified circuit which replaced 16 measurement units with 16 precise resistors was developed, and an experiment was carried out to verify the time division current driving project. As a result, the output voltages obtained from the experiment were linear to the corresponding resist- ances, and the slope of the fitting line depicting the dependence of the output voltages on the corre- sponding resistances was equal to the output current from the constant current source. A proper low- pass filter was designed to remove the glitches resulting from the analog switches, and an ideal out- put waveform was obtained. It was proved that the project of the time division current driving circuit for the photoconductive sensor array was practical and reliable.