大面阵CMOS快照模式焦平面读出电路设计分析

Analysis of Large Scale CMOS Snapshot Readout Circuit for Focal Plane Array

针对一款大面阵(640×512元)快照模式制冷型红外焦平面用的读出电路进行了初步分析验证。该读出电路采用改进D I结构,先积分后读出的积分控制模式,像素尺寸为25μm×25μm,芯片已在0.5μm双硅双铝(DPDM)标准CMOS工艺下试制。首先对该电路结构及工作原理进行分析,并对输入级等电路的传输特性进行仿真验证,最后给出探测器阵列与读出电路芯片互连后的测试结果。结果表明该读出电路适用于小像素、大规模的红外焦平面阵列。

A large scale, 640×512 pixel, readout integrated circuit （ROIC） with snapshot integration mode for cooled IRFPA has been fabricated using a standard O. 5μm double-poly double-metal （DPDM） CMOS process. The pixel pitch is 25μm and an improved direct injection （DI） input circuit is used. The integration control mode is integrate-then-read. In this paper, the circuit＇s structure and operation principle are analyzed first. Then, the transfer characteristic of the input unit cell is simulated and the testing results of an IRFPA interconnected with this ROIC are given at last. The results show that this ROIC is feasible for large format and small pixel IRFPA.