Research On Uncooled Infrared Focal Plane Array Readout Circuit Based On 0.18?m Technology

Due to its small size,low power consumption and strong practicability,infrared detectors have been widely used in high-end fields such as industrial control,military reconnaissance and aerospace.The advent of non-refrigerated infrared detectors is another revolution in the field of infrared detection.The breakthrough has quickly attracted the attention of all countries;the two core structures of the detector:the readout circuit and the sensible pixel array have also become the two starting points for the study of uncooled infrared detectors.The production of smaller size pixels,larger array readout circuits,lower cost,and higher integration of infrared detection chips is the main research direction of current uncooled infrared focal plane arrays.Based on the process of TSMC 0.18?m 1P6M,this work designs a 384×288 array uncooled infrared focal plane readout circuit based on 25?m×25 pm size pixels.The circuit mainly includes a capacitive feedback transimpedance amplifying circuit(CTIA),a portion of sampling,hold,buffer output and an equivalent pixel circuit.Where the capacitive feedback transimpedance amplifying circuit(CTIA)integrates and amplifies the current difference between the effective pixel branch and the blind pixel branch,the part of sampling,hold,and buffer output processes the integrated voltage signal,and the equivalent pixel circuit is used for pre-tested before production of pixels in Micro-mechanical systems(MEMS).By analyzing the working principle of the MEMS pixel infrared detector readout circuit,the analytical expressions of the parameters such as temperature rise,resistance value change,response rate and noise are obtained,and a new equivalent pixel circuit is designed.Before the completion of the meta-production,the equivalent circuit is used to perform pre-test on the characteristics of the readout circuit,thereby reducing the manufacturing cost of the infrared detector.In this paper,a new CTIA structure with differential current for integral amplification is designed.The enable terminal is set between each module,and dynamic power management technology is adopted to reduce system power consumption.In addition,a new coarse calibration technique is proposed for pixel resistance to eliminate system deviation caused by external environment or process error before effective pixels are exposed to infrared radiation.At the same time,the pixel size corresponding to the readout circuit of the subject is 25 ?m×25?m,and the readout circuit is also applicable to pixel circuits of other sizes.Finally,the modules in the readout circuit of the uncooled infrared focal plane array are designed,simulated and analyzed under Cadence.The simulation for front-end is finished,and then layout is designed.