典型ADC电路中斜坡发生器瞬时剂量率效应时序敏感性分析  

Timing Sensitivity of Ramp Generator of Typical ADC Circuit Radiated by Transient Dose Rate

作　　者：伏琰军 韦源 左应红 朱金辉 牛胜利 FU Yanjun;WEI Yuan;ZUO Yinghong;ZHU Jinhui;NIU Shengli(State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Xi’an 710024,China)

机构地区：[1]强脉冲辐射环境模拟与效应全国重点实验室,西安710024

出　　处：《现代应用物理》2024年第6期94-101,共8页Modern Applied Physics

基　　金：国家重点研发计划资助项目(2020YFA0709800)。

摘　　要：基于器件级、电路级多层级仿真工具,构建了考虑剂量率发生时刻及剂量率大小的瞬时剂量率辐射效应仿真模拟方法,并针对图像传感器的模数转化电路ADC中的斜坡发生器核心子电路,开展了瞬时剂量率辐射效应研究,结合工作时序给出了不同剂量率及其发生时刻条件下,斜坡输出信号的响应变化。研究发现,除剂量率外,剂量率效应发生时刻也是影响斜坡发生器电路的重要因素,即在同一剂量率条件下,发生时刻的差异会导致其产生约50%的相对偏差,故在后续电路实验或仿真中需要额外考虑。进一步,从电路功能角度开展了斜坡发生器电路模块由于瞬时剂量率辐射效应的响应,及其对完整ADC电路的影响分析研究。结果表明,斜坡输出信号斜率在剂量率辐射效应条件下的变小,会使经过ADC电路后的十进制逻辑信号数值增大,从成像质量方面会导致像素单元的亮度增大。仿真结果和实验观测到的结果一致,即图像传感器像素单元阵列在剂量率辐射效应影响下出现亮条纹、亮斑等现象。本文相关研究可为后续考量或评估CMOS传感器整体辐射效应提供参考。The analog digital converter(ADC)circuit is responsible for converting the photocurrents into a digital signal that can be recognized by machinery.And the ramp generator is the most important module in ADC circuit,where the linearity and accuracy of ramp signal directly determine its performance.In this paper,a simulation method for TDRE is established that can take into account the occurrence time of the dose rate and its magnitude,based on device-level and circuit-level simulation tools.The TDRE of the typical ramp generator circuit is investigated,and the variations of its output signal under different dose rates and different occurrence times are provided in combination with its operating time.The results show that the occurrence time of the TDRE is a crucial factor influencing the ramp generator circuit.Under the same dose rate,a difference in the occurrence times can lead to approximately 50%relative deviation,which should be taken into consideration in the subsequent circuit experiments or simulations.Furthermore,the impact of the TDRE on the complete ADC circuit due to the ramp generator module is examined from the functional perspective.The results show that the decrease in the ramp of the ramp output signal will increases the value of the decimal logic signal after passing through the analog to digital converter circuit(ADC),and resulted in an increase in the brightness of the pixel unit,and the phenomenon of bright stripes and bright spots in the pixel array,which is consistent with the experimental result.Based on the relevant calculation results,it could offer a reference for the subsequent consideration or evaluation of the overall radiation response of CMOS sensors.

关 键 词：斜坡发生器电路 模数转换电路 瞬时剂量 双指数电流源 故障注入 

分 类 号：TL99[核科学技术—核技术及应用] O571[理学—粒子物理与原子核物理]