针对中大规模红外焦平面对高速读出的需求,研究并设计了一款20 MPixel/s红外焦平面高速读出电路。读出电路单元电路由电容负反馈运放输入级、相关双采样、源随输出级电路组成,总线输出级采用基于低功耗推挽运放的跟随器结构。研究了输出级运放像元信号建立时间和负载电容的关系,给出了20 MPixel/s高速读出的负载电容适用范围。采用0.5 μm Mixed Signal CMOS工艺研制了一款红外焦平面高速读出电路芯片,和InGaAs光敏芯片耦合后实测读出速率达到20 MPixel/s,像元信号之间最大上升时间为17 ns。

A 20 MPixel/s high-speed readout integrated circuit(ROIC) is designed in order to satisfy the high-frame-rate readout requirement of large-format infrared focal plane array(FPA). The ROIC pixel consists of capacitive-feedback trans-impedance amplifier(CTIA) input stage, correlated double sampling circuit(CDS) and source follower. Low power push-pull amplifier is implemented for high speed buffer and the application scope of load capacitor is provided after a detail analysis of relationship between settling time and load capacitor. A high speed ROIC has been fabricated with 0.5-μm mixed signal CMOS process and interfaced with InGaAs detector arrays. Test results show that the readout rate achieves 20 MPixel/s and maximum rise time is about 17 ns.