Design Of Readout Circuit For GM-APD Array Detector

The avalanche photodiode has an extremely high gain,high detection sensitivity and fast recognition.In recent years,the avalanche photodiode is widely used in target detection under the weak light environment and the rapid recognition of hidden targets.It have become a new type of speedy development.As a connection between the detector and the subsequent signal processing circuit,the performance of the read-out circuit affects the detection efficiency of the detection system directly.In this paper,we aiming at problems of slow quenching,long dead-time,and low ranging accuracy for readout circuits of medium and small-scale array detectors,built on the in-depth study of the working principle of the APD arrays,a readout circuit suitable for 8×8 APD array detector is designed,and the readout circuit is verified by single photon laser ranging system.Firstly,we describe the principle of single photon detection,and focus on the analysis of APD single photon detection principle and performance index,providing a theoretical basis for the design of the readout circuit system.Secondly,we designed the architecture and working sequence of the read-out circuit system,and set up the APD electrical model,which lays the foundation for the subsequent module circuit simulation.Thirdly,we designed the key modules in the read-out circuit system: quenching circuit,TDC and temperature control circuit.Finally,the experimental platform of single photon laser ranging system is built to verify the effectiveness of the read-out circuit,which designed in this paper.In this paper,we design a readout circuit,which shorten the dead time of GM-APD array effectively and improves the detection efficiency.It provides a theoretical basis for the follow-up study of CMOS fully integrated array detection focal plane and readout circuit for large-scale detector array.