自稳零低噪声CTIA读出电路研究

Study of Autozeroing Low-noise CTIA Readout Circuit

红外探测器在国防航天领域应用广泛,其低噪声读出电路是获得有用清晰红外图像的基础。当探测器工作在高背景微弱信号下时,常出现噪声扰动大,各元信号高低不平,部分信号无法读出的问题。针对国内航天工程应用需求,文章设计了一种低噪声的新型读出电路。该电路在传统CTIA的基础上,设计了自稳零技术和新型相关双采样电路,对噪声抑制表现出优良的作用。可应用于低温中波线列红外HgCdTe航天探测器的信号读出以及其他低温和常温探测器的信号读出,工作温度范围为77~300K。基于0.35μm,5V-CMOS工艺进行了10×1线列读出电路后仿真验证与流片,结果表明,与传统CTIA电路对比,输出噪声下降44.7%,总输出噪声仅为72.1μV。

Infrared detectors have diverse applications in the defense and aerospace fields,and they rely on low-noise readout circuits for acquiring useful and clear infrared images.Detectors operating under high-background and weak-signal scenarios encounter issues such as substantial noise disturbances,uneven signals across elements,and unreadable signals.To satisfy the requirements for the application of infrared detectors in aerospace engineering in China,we designed a novel low-noise readout circuit based on the traditional capacitive transimpedance amplifier(CTIA)in this study.The circuit design utilized autozeroing technology and a new correlation double-sampling circuit with excellent noise suppression capability.We applied the proposed circuit to signal readouts in common midwave line-array infrared HgCdTe space detectors and other low-and normal-temperature detectors with operating temperatures within 77~300K.Further,we performed simulation verification,followed by the tape-out of a 10×1 line-array readout circuit using a 0.35μm 5V CMOS process.Our results showed a total output noise of 72.1μV,which was 44.7%lower than that of the traditional CTIA circuit.