截止波长为2.5μm的延伸波长InGaAs探测器在航天航空遥感等领域有着重要应用。由于晶格失配,相同温度下它的暗电流比截止波长为1.7μm的常规InGaAs探测器高2~3个数量级。从焦平面的耦合接口出发,研究了一种新型的Autozero输入级电路,通过大幅降低输入失调电压来减小耦合接口处延伸波长InGaAs器件的偏置电压和暗电流。在CTIA采样反馈回路中设计了一种双电源电压工作的反相器,通过消除开关管两端电压差抑制了非理想开关漏电对采样失调电压的影响。分析了输入端采样电容和失调电压的关系,优化设计后仿真实现了16.5μV的低失调电压。 The extended wavelength InGaAs detector with cutoff wavelength of 2.5μm has important applications in aerospace remote sensing and other fields. Due to the lattice mismatch, its dark current at the same temperature is 2 to 3 orders of magnitude higher than conventional InGaAs detectors with a cut-off wavelength of 1.7 μm. Starting from the Focal Plane Coupling Interface, a new type of Autozero input stage circuit has been studied to reduce the bias voltage and dark current of extended wavelength InGaAs devices at the coupling interface by drastically reducing the input offset voltage. In the CTIA sampling feedback loop, a dual-supply voltage inverter is designed to eliminate the influence of non-ideal switching leakage on the sampling offset voltage by eliminating the voltage difference across the switch. The relationship between the sampling capacitor and the offset voltage is analyzed. After the optimized design, the low offset voltage of 16.5μV is achieved.