Key Circuits Design Of Uncooled Infrared Imaging System Using SOI Diode

As a main component of infrared imaging systems, Infrared Focal Plane Array(IRFPA) has been an international research hotspot. Traditional cooled infrared focalplane array (IRFPA) has complex structure and the cost is high. However, with theexcellent characteristics of no need of coolness and low cost, uncooled infrared focalplane array (UIRFPA) has an extensive application prospect. The structure ofSilicon-on-Insulator (SOI) diode uncooled infrared focal plane array is simple, and ithas a good compatibility with CMOS process. The detector unit does not depend onmaterial performance. Therefore it has a high value for application and research.In this paper, key circuits for384×288SOI diode uncooled infrared focal planearray imaging system have been designed. Work is mainly composed of two parts.One is the design of readout circuit (ROIC) module. The integrated amplifier unit, thecharge amplifier circuit, the sample and hold circuit, and the output buffer have beencompleted. It provides detailed information about the working principle and designingprocess in this paper. The analog circuit layout has been completed under0.35μm5VCMOS process. Also, the post-layout simulation has been finished. Simulation resultsshow that the readout circuit is able to read, amplify and export the weak voltagesignal from detectors. The other part is the design of a Pipeline ADC in signalprocessing module. The design of sampling and holding circuit of a12-bit20MS/sPipeline ADC has been completed in this paper. The S/H circuit has beenimplemented under0.18μm CMOS process. It has been tested to verify that the S/Hcircuit can achieve more than12-bit ENOB, when the power supply is3.3V, the inputsignal frequency is5MHz, and the sampling frequency is50MHz.The key circuits of uncooled infrared focal plane array imaging system using SOIdiode have been designed in this paper, which lays the foundation of laterconstruction of infrared detector array imaging system.