Design Of Pre-amplification Circuit For Perovskite X-ray Detector

X-ray detection,utilizing the high penetrability of X-ray to image the interior of materials,is widely used in security,industrial inspection,medical diagnosis and other fields.Digital flat panel detector with direct detection has become the first choice for high spatial resolution X-ray imaging.Compared to the current commercial flat-panel detector,amorphous selenium??-Se?,halide perovskite which is represented by MAPbX₃?MA=CH₃NH₃,X=Cl,Br,I?has better stability,higher sensitivity and is easy to manufacture large area devices at a low cost.Therefore,it is of great hope for perovskite to replace?-Se as the next generation of detection material for X-ray direct detection.The necessary condition for digital X-ray detection is to realize analog-to-digital conversion for signals from the detector,so that the computer can recognize it.Due to the response of the detector is very weak?hector-picoammeter level,typically?,it is necessary to use the pre-amplifier circuit to amplifer the signal before analog-to-digital conversion.It could not only ensure that the signal will not be buried in the noise during the process of data transmission after amplification,but also meet the requirement of the data amplitude size?millivolt level,typically?for analog-to-digital conversion.This paper studies the pre-ampilifer circult for perovskite X-ray detector,finishes the design of the pre-ampilifer circult,realizes the amplification of detection signal to make the detection signal easy to be received and processed by the back-end circuit.Based on the theory of X-ray detection,this paper introduces the generating mechanism of X-ray,the structure of digital X-ray detection system and the characteristics of perovskite.The design proposal uses MAPbBr₃ single crystal provided by the laboratory as the photoconductive detector.It is based on the direct detection as signal readout method to design the circult adopted AFE0064 as the integrated amplifier,STC89LE52 single chip microcomputer as the control unit,CH340 as the data transmission module.This proposal can realize the detection and amplification of 64 channels'weak signal output simultaneously.Design revolves around the hardware circuit,including chip selection,power management,schematic drawing,and there is a detailed introduction about the working principle of the hardware circuit modules.In the software aspect,it uses C language to implement the control of timing signal so as to meet the demand of signal logic.At the end,test verification shows that the gain of the pre-amplifier circuit is about 1.5G?which can meet the demand of signal amplification.Furthermore,the source of circuit noise is analyzed,and a statistical model is established to calculate the noise and the signal noise ratio is 47.37 dB.