Design Of 1280×1024-25?m Multi-functional Infrared Readout Circuit

Infrared imaging technology is one of the main technologies for obtaining information in the military field and it is also widely used in the civilian field.Infrared focal plane array is the core photoelectric device in infrared imaging technology.It consists of an infrared detector array and an infrared readout circuit.The infrared readout circuit directly affects the quality of imaging,which is extremely important.The research on infrared readout circuit in China started late,and the research and design of large-scale readout circuits is fewer.Therefore,it is of great significance to design a large-scale infrared readout circuit.A large-scale and multi-functional CMOS infrared readout circuit of 1280 1024-25?m is designed in the thesis,which is suitable for photovoltaic short-wave infrared detectors.First,the current research situation at home and abroad and the difficulties faced by the increase in the scale of readout circuit arrays is studied,and the overall architecture of the readout circuit is determined by investigating the research results of infrared readout circuits.Second,the performance characteristics of various input stages are studied,and the Capacitance Trans-impedance Amplifier(CTIA)of high input efficiency is selected as the input stage according to the characteristics of short-wave infrared detectors and the requirements of the high dynamic range of the readout circuit.The circuit structure of the CTIA pixel unit is improved,and the integration capacitor can select an appropriate capacitance value according to the background intensity,so that the readout circuit is suitable for a wider background intensity range.Third,the column output bus is divided into 16 groups,which can shorten the settling time of the signal on the column output bus and simplify the timing design of multiple outputs control circuit.Finally,digital control circuits such as row selection circuit and column selection circuit and the overall circuit working sequence are designed to realize window selection function of window opening of any size and selection of reading order and multiple outputs function of four-channel output and eight-channel output switching.What is more,each function is verified through simulation.Based on SMIC 0.18?m 5V digital-analog mixing process,the schematic of the readout circuit is designed and simulated,and the layout of the key modules is designed.According to the result of the simulation,under the output speed of 10 MHz,the output swing is 3.1V,the linearity is 99.69%,the dynamic range is 81.26 d B,the power consumption of eight-channel output is 566.94 m W.The simulation results meet the requirements of the design index.