Design And Analysis Of Front-end Readout Circuit For X-ray Detector

X-ray is a kind of invisible light with strong penetration.It is wildly used in medical imaging,industry testing and safety inspection.With the expanding application field,the environment is getting more complex and higher quality of image is required.According to the actual requirements,this dissertation studied and designed the front-end readout circuit for X-ray detector.The dissertation introduced the tendency of the front-end readout circuit applied in X-ray detector.With the increasing energy range of the particles to be measured,the dynamic range of front-end readout circuit is increasing,operating frame rate is getting higher,while the sensitivity of detecting low-energy particle is low and output signal has shortcomings in linearity,consumption and noise.To solve these problems,increase the sensitivity while detecting low-energy particles and has the performance of high frame rate,high linearity,low consumption and low noise,the dissertation studied and designed the framework of the front-end readout circuit in X-ray detector with adaptive sensitivity by the reference of researches from other countries.In the framework,Capacitance Trans Impendence Amplifier(CTIA)can realize the high linearity of output signal.Correlated Double Sampling(CDS)circuit is used to eliminate noise and improve the SNR of output signal.And integral capacitance control block is designed to realize adaptive sensitivity.Based on 0.13 um CMOS technology process,the dissertation designed the schematic and layout of the front-end readout circuit.The relevant design objects and simulation results are given.The chip is taped out and the test results showed that the front-end readout circuit designed in the dissertation applied in 32×16 array can realize the function of adaptive sensitivity.With the power of 3.3V,the front-end readout circuit can reach the frame rate of 10 KHz.It has the linearity of 99.95%,the consumption of 85.4uW,the output range of at least 1.5V and the ENC of 62.5e-with the pixel size of 150um×150um.