具有温度补偿的APD阵列信号采集电路

发布时间：2018-07-23 16:41

【摘要】：对APD阵列信号采集电路进行了深入研究,着重分析其增益温度补偿实现方法。系统采用集成DC-DC高压模块为APD阵列提供高压偏置,以提高系统可靠性。高压模块输出电压可通过数字电位计进行软件控制,也可通过常规电位计手动调节,增强系统增益调节的灵活性。为保持APD增益恒定,需在环境温度变化时,APD偏压与APD击穿电压成比例变化。详细分析了基于温敏二极管、温敏电阻及带温度传感器的数字电位计的增益温度补偿方法。APD阵列在激光照射下生成的电流信号经跨阻放大器转换成电压输出。最后,对电路性能进行了测试。分析表明:基于温敏二极管的增益补偿方法设计简便;采用温敏电阻的增益补偿方法只能实现部分温度范围的线性补偿;应用带温度传感器的数字电位计进行温度补偿时存在锯齿效应,该锯齿效应与温度分辨率有关,在温度分辨率为4℃时,偏差最大可达4.57 V。测试结果显示:在激光脉冲宽度为5.1 ns时,模块输出电压脉宽达到10 ns。整个电路满足后续系统设计要求。
[Abstract]:The APD array signal acquisition circuit is studied, and the method of gain temperature compensation is analyzed. The system uses integrated DC-DC high voltage module to provide high voltage bias for APD array to improve system reliability. The output voltage of high voltage module can be controlled by software by digital potentiometer or manually adjusted by conventional potentiometer to enhance the flexibility of system gain regulation. In order to keep the gain of APD constant, the bias voltage of APD is proportional to the breakdown voltage of APD when the ambient temperature changes. The gain temperature compensation method of digital potentiometer based on temperature sensitive diode, temperature sensitive resistor and temperature sensor is analyzed in detail. The current signal generated by APD array under laser irradiation is converted into voltage output by transimpedance amplifier. Finally, the performance of the circuit is tested. The analysis shows that the gain compensation method based on temperature sensitive diode is easy to design, and the gain compensation method based on temperature sensitive resistance can only realize linear compensation in part of temperature range. The sawtooth effect exists when the digital potentiometer with temperature sensor is used to compensate the temperature. The sawtooth effect is related to the temperature resolution. When the temperature resolution is 4 鈩，

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