Design Of 320*256 Dual-band Infrared Readout Circuit

The Infrared Readout Integrated Circuit is a key component of the infrared focal plane array and is critical to improving the quality of infrared imaging.The function of the infrared readout circuit is to integrate the current generated by the detector into a voltage and achieve flexible output of the effective signal in the pixel unit array.Compared to single-band detection,dual-band detection can more accurately identify the target in a complex background,which will require a two-color readout chip.In this thesis,a two-color infrared readout circuit is designed.By inputting different control commands,the working mode of the detector is adjusted,so that the readout circuit outputs the detection signals of different bands in the adjacent frame image,and finally realizes the function of two-color detection output.In order to improve the readout rate,the working process of the infrared readout circuit is divided into four steps: control command input,register configuration,pixel unit integration,and signal output.The pixel unit adopts the direct injection input stage,which reduces the complexity,area and power consumption of the pixel unit.The function of flexible window opening is designed,which can get different sizes of readout array,reduce the readout time and improve the circuit readout rate.In addition,a multi-channel output design is used to achieve up to four channels of output,further increasing the readout rate.Based on the Chartered₀.18?m digital-analog mixing process,the schematic and layout are designed,and the simulation and performance analysis are completed.The dynamic range and output linearity are simulated and analyzed.For the output swing of 2.8V,the dynamic range of the circuit is above 81 dB and the output linearity reaches 99.14%.At the frequency of 6.25 MHz,the frame rate of the readout circuit is about 65 fps.The power consumption of the ROIC operating under the single-channel and four-channel output are 58.3mW and 119.4mW,respectively.The simulation results meet the requirements of the design specifications.