Research On Non-uniformity Correction Of Uncooled Infrared Focal Plane Detecto

In the design of uncooled infrared detector,the readout circuit is the core of the infrared focal plane,its performance depends on the application of infrared focal plane.The main problem is the chip is due to the influence of external factors and heterogeneity,the infrared detector focal plane heterogeneity correction technology research one of the hot issues in recent years.When the band-gap reference circuit provides accurate reference voltage,the voltage signal generated by the nonuniformity correction circuit is transmitted to the high power rejection ratio output buffer circuit,so that the infrared detector can produce more accurate output voltage.Therefore,the non-uniformity of Infrared Focal Plane Array readout circuit is studied based on TSMC 0.18μm technology in the dissertation.In the dissertation,each module of uncooled infrared detector with array size of640×480 and pixel size of 17μm is studied to reduce the influence of non-uniformity on readout circuit.The following studies are carried out in the dissertation:（1）The new non-uniformity correction circuit proposed in the dissertation adopts the structure of common source and common gate current mirror,and the amplifier negative feedback structure is added to the light-blind pixel circuit.By adjusting the proportional branch current,the final output non-uniformity correction total compensation current is 368 n A.When the input voltage is 2.5V,the integrated current id after correction is 44.24 n A.The integration time of the integrated circuit is shortened to 225.43 ns,the non-uniformity of the circuit is reduced to less than 3%,and the output voltage is more stable.（2）A low power consumption,high gain and low noise output buffer structure is designed,which is innovative to the traditional rail-to-rail structure at the input stage.The output buffer adds a constant transconductance structure at the input stage,and the low frequency gain is 106 d B at the frame rate of 60 Hz,the load capacitance is50 pf,and the load resistance is 100kΩ The unity-gain bandwidth is 40.37 MHz,the phase margin is 103.3°,the circuit is stable,and the input noise is 1.72nV/Hz^1/2.（3）A second-order curvature compensation and high power rejection ratio（PSRR）bandgap reference voltage（BGR）circuit for infrared focal plane detector is designed.The circuit structure is improved by adding power rejection ratio to the bandgap reference circuit.The output voltage of the second-order curvature compensated bandgap reference voltage Vref is 1.629 m V,the temperature drift coefficient of the reference voltage is 8.65ppm/℃,and the power supply rejection ratio（PSRR）of the circuit structure is 128 d B.