Study On New Structural High Performance CMOS Readout Circuits For IRFPA

Infrared image technique is becoming more and more common, and expected to be used in many fields of the national economy, especially in the military fields. Infrared-focal-plane-array (IR FPA) is mainly made up of two parts: detector and readout-circuit (ROC). IR FPA has a high requirement to its ROC, such as low power consumption, stable detector bias, small pixel size and pixel pitch, especially ways of suppressing the background current before the integration node in the large background current situation to improve the detecting sensitivity and the signal noise ratio, and to reduce the integration time and integration capacitor. However, the present technologies have their defects, like complex circuit, which can not be applied to the large format IR FPA, sensitive to the threshold voltage, without background current suppression, and low dynamic range, which can not be applied in the high background circumstances.Aiming at the above problems, this author has read many latest corresponding materials at home and abroad, and has got a general view of the state of arts of IR FPA. As one of the main researchers, this author accomplished the project supported by NSFC (granted NO. 60077025), Study on New Structural High Performance CMOS Readout Circuit for IR FPA, and also participated in other projects.To many key technical problems in CMOS ROIC design, such as MOS capacitor, channel length modulation effect of MOS FET, CMOS simple current mirror (CM), Wilson current mirror, and several readout circuit structures (DI, BDI and BGMI structure), this author made deep and systemic analyses about the operational principle and circuit design, and also using electronic CAD (PSPICE, Tanner Ledit, and MAXPLUS II, etc.), emulated many types of ROIC at different operational circumstances and technical conditions.And based on the general analysis and understanding of the state of arts of CMOS readout techniques for IR FPA, this author points out the strong points and weak points of the state of art of ROIC, and creatively improves several new types of CMOS readout techniques for IR FPA, just like improving the present background current suppression technique in paper [12], and brings forth a new kind of dummy background current suppression technique, and puts forward the novel dynamic source-follower for the first time, on the basis of which this author constructs a novel correlated-double-sampling (CDS) technique.This author accomplished designing the corresponding circuits and their IC layout, and programmed many kinds of signal sources, including that for the novel CMOS readout technique for IR FPA with dynamic source-follower.