Design Of BDI ROIC For Infrared Focal Plane

As the key device of infrared imaging system, infrared focal plane array has been widely used in a variety of detection field. Infrared focal plane array is mainly composed by infrared detector arrays and readout circuits. The readout circuit is the main hub to connecting infrared detector arrays and signal processing system. A high-performance readout circuit is the key point to the quality of infrared imaging.This thesis mainly designed a BDI infrared sensing circuit chip. First of all, the key parameters involved in the infrared sensing circuit have been analyzed emphatically. The efficiency of the injection of several different pixel unit structure, the influence factors of dynamic range and linearity have been researched. Due to the limitations of layout area and detector bias voltage, the traditional pixel unit structure cannot be directly used in this thesis. Therefore, in this thesis, the improved traditional pixel unit circuit structure has been put forward and gotten rid of the traditional sampling capacitance. Then the switch control tube has been joined, so as to control the infrared detector bias voltage more effectively. On this basis, the column of readout circuit processing unit and output buffer module circuit has been designed in detail. In order to provide greater output swing and higher voltage transmission accuracy, both of the circuits has selected the two stage amplifier with Miller compensation as the basic structure of the circuit unit. Finally, layout has been designed and taped out based on the CSMC 0.5μm CMOS process.The test results showed that charge capacity of the designed chip is 80.53 Me, the dynamic range is 84.61 dB,the linearity is 98%, the power consumption is 56 mW, and the output swing is 3.4V, basically meet the design requirements.