Abstract:
In order to improve the dynamic range of the infrared readout circuit and enhance the quality of infrared imaging, a high-performance infrared readout circuit with a four-pixel time-sharing capacitive feedback transimpedance amplifier (CTIA) and a bandgap reference source were designed by adding a dark current suppression module circuit. Two reference voltages of 586 mV and 293 mV were generated by bandgap reference source. Among them, the temperature drift coefficient of the reference voltage value of 293 mV reaches 1.49×10
-6/℃, which can provide stable voltage bias for the gate and source of the shunt tube to achieve accurate skim of the dark current. The results show that a wide dynamic range of integral voltage readout of current signals from 10 pA to 10 nA can be realized, and the readout data are fitted by a linear fit with a goodness of fit (
R2) of 0.9992, which indicates that the circuit performs well. This study can be applied in the future to linear array and focal plane array infrared detectors.