A General-purpose EMCCD Drive System

Electron multiplying CCD(EMCCD)is the focus of research and development in the field of micro-imaging at home and abroad,it not only has the characteristics of traditional CCD,but also has high sensitivity,high quantum efficiency and low noise advantages,mak-ing it very suitable for military reconnaissance,astronomical observation,biomedical and other fields of low-light imaging.But the EMCCD production process and chip performance testing level is not mature enough in China,and commonly used EMCCD imaging system is only applicable to the imaging and application of a single model chip,which leads to its limi-tations.In this paper,a general EMCCD drive system is designed for a variety of common EMCCD chips,providing a platform for driving and performance testing of different types of chips.Firstly,the paper describes the working principle and working noise of EMCCD.Then,the overall design scheme of the general EMCCD drive system is put forward by using NI computer as the control end.Secondly,the paper introduces the structure characteristics of EMCCD and sums up the common features of drive signals in amplitude,timing and other aspects by focusing on the drive requirements of varieties of common EMCCD.Based on this,the design idea and re-quirements of general EMCCD drive system circuit are put forward.In terms of system hardware circuit,this paper achieves the versatility of the system circuit,so that the transfer clock drive circuit,the multiplication clock drive circuit and the DC bias voltage circuit and the device backplane can meet the drive requirements of different chips.The sine wave signal of multiplied clock in the circuit is achieved by using Cordic algorithm and integrated opera-tional amplifier.In this paper,the acquisition and real-time display of image signal is done by the related double sampling circuit and a 14-bit A/D quantization sampling card.In terms of circuit optimization,reference plane,digital-analog mixed signal circuit and signal transmis-sion of PCB are optimized through the circuit design rules and signal integrity theory.In terms of software system,the system control,timing drive,sampling and imaging procedures are designed in this paper.Subsequently,two chips are used in the signal debugging to verify the feasibility and versatility of the drive circuit.Finally,the CCD97 chip is taken as an example for the test of system imaging,noise lev-el,multiplication gain and integration time.The results show that the system can achieve the expected function.