Design Of Low-noise Front-end Circuit In X-ray Pixel Detector

Since the idea of using X-ray pulsars for autonomous navigation of spacecraft was proposed,it has attracted attention from all parties because of its superior performance such as high precision and anti-interference.With the development of pulsar autonomous navigation technology,high-speed,high-precision,and low-noise X-ray detectors have become a key part of pulsar autonomous navigation technology.Therefore,the noise of the front-end readout circuit of the X-ray detector readout chip Performance also puts forward higher requirements.This paper has carried out the research and design of the readout circuit chip for the X-ray pixel detector,carried out the design and simulation verification of the low noise front-end readout circuit in the X-ray pixel detector readout circuit chip,and realized the detection of the incident X-ray pulse signal.Based on the extraction and output of the hit time information and energy amplitude information,and based on Hua Hong Hongli's0.13?m CMOS process,the layout design and post-simulation of the front-end readout circuit have been completed.The pixel array of the readout circuit chip is 40×50,the size of a single pixel layout is 80?m×80?m,and the chip layout size is 5000?m×5000?m.The post-simulation results show that the total current of a single pixel is 15.11?A,the charge-to-voltage gain is 0.088mV/e~-,the"Time Walk"deviation is 23.3ns,Nonlinearity is 2.35%,and ENC is 40.61 e~-,the total current of the read circuit chip is 31.5mA.After the successful tapeout and packaging of the first version of the CMOS readout circuit chip XPIXR?v1,the test work was carried out,and the test results were summarized and analyzed.The test results showed that the total current of the CMOS readout circuit chip XPIXR?v1 was 32mA,Nonlinearity is 2.79%,and ENC is 38.75e~-,which meets the design requirements.Carried out the analysis of the pixel consistency of the CMOS readout circuit chip,analyzed the reasons for the inconsistency of 2000 pixel units,and optimized the consistency of the front-end readout circuit,including the double-ended input charge-sensitive amplifier,voltage comparator,and compensation DAC,etc.,and carried out the simulation and layout design of the front-end circuit,the size of a single pixel layout is80?m×80?m.Based on this work,the circuit and layout design of the second version of the CMOS readout circuit chip XPIXR?v2A have been completed.The pixel array is40×50 and the total layout size is 5000?m×5000?m.The post-simulation results of the front-end readout circuit show that the total current of the optimized pixel unit is 18.19?A,the gain is 0.079mV/e~-,the"Time Walk"deviation is 113.6ns,Nonlinearity is 1.53%,and the inconsistency between pixels can be controlled within the peak-to-peak value of10mV,that means the standard deviation is within 1.6mV,and ENC is 27.06e~-.