Shanghai Institute of Technical Physics of the Chines
The National Natural Science Foundation of China (62175250)
目前红外探测器采用传统读出方法很难通过一次积分实现其本身的动态范围。为实现红外探测器的大动态范围不换档读出，引入脉冲频率调制（Pulse Frequency Modulation，PFM）结构，同时为保证弱信号时的注入效率，结合CTIA输入级，对红外探测器不换档大动态范围读出方法进行研究。提出一种CTIA输入级脉冲频率调制（PFM）读出方法，在系统级层面搭建实验系统并结合短波红外InGaAs单元探测器进行数字量化实验。详细分析了强信号时由系统结构延迟时间引起的转换线性度问题，并建立非理想条件下的数字量化转换模型。实验结果显示，提出的CTIA输入级PFM红外探测器读出方法动态范围达到97 dB, 为红外探测器不换档大动态范围读出提供了一种可行方案，并为数字化读出电路设计奠定理论基础。
The current infrared detectors are difficult to achieve their own dynamic range by primary integration using traditional readout methods. In order to achieve large dynamic range readout of infrared detectors without changing gears, this paper introduces Pulse Frequency Modulation (PFM) and adopts the CTIA input stage structure to ensure the injection efficiency when the signal is weak, and investigates the method of large dynamic range readout of infrared detectors without changing gears. A CTIA input-level pulse frequency modulation (PFM) readout method was proposed to build an experimental system at the system level and conducted digital quantization experiments with short-wave infrared InGaAs cell detectors. The conversion linearity problem caused by the delay time of system structure at strong signal was analyzed in detail, and a digital quantization conversion model under non-ideal conditions was established. The experimental results show that the dynamic range of the proposed CTIA input stage PFM IR detector readout method reaches 97 dB, which provides a feasible solution for large dynamic range readout of IR detectors without changing gears, and lays a theoretical foundation for digital readout circuit design.