自稳零低噪声CTIA读出电路研究

Study of Autozeroing Low-noise CTIA Readout Circuit

摘要:

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。

Abstract:

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.