640×512-5μm InGaAs短波红外焦平面读出电路设计

Design of Readout Circuit Based on 640×512-5 μm InGaAs Shortwave Infrared Focal Plane

为了适应第三代红外焦平面高密度、微型化发展方向,设计了一款大面阵小像元低功耗640×512-5μm InGaAs短波红外焦平面读出电路。重点研究了3T像素单元简易结构的性能,分析其对芯片暗电流、焦平面噪声的影响,实现了卷帘曝光工作方式、列级缓冲器动态工作以及四通道输出功能。利用可编程增益放大器,实现增益可调以及噪声抑制功能。基于0.18μm 3.3 V标准CMOS工艺,在输入时钟频率为5 MHz条件下,对小像素单元进行性能分析,阵列窗口进行四通道输出以及线性度仿真。结果表明,电容反馈跨阻放大器(CTIA)输入级偏压变化约30 mV,工作帧频为54 Hz,输出摆幅为1.7 V,最大功耗小于150 mW,线性度为99.987%。

In order to adapt to the development direction of high density and minization of the third generation infrared focal plane,a large array small pixel and low power consumption of 640×512-5 μm InGaAs shortwave infrared focal plane readout circuit was designed in this paper.The performance of the simple structure of 3T pixel unit was studied,and its influence on the chip dark current and focal plane noise was analyzed to realize the rolling curtain exposure operation mode,the dynamic operation of column level buffer and the four-channel output function.Programmable gain amplifier was used to achieve gain adjustment and noise suppression.Based on the standard CMOS technology of 0.18 μm 3.3 V,the performance analysis of the small pixel unit and the four-channel output of the array window and the linearity simulation were carried out at the input clock frequency of 5 MHz.The results show that the bias change of the input stage of CTIA is about 30 mV,the working frame frequency is 54 Hz,the output swing is 1.7 V,the maximum power consumption is less than 150 mW,and the linearity is 99.987%.