A Dual-Exposure Readout Integrated Circuit for Dynamic Range Enhancement in SWIR Image Sensors

This article presents a prototype short-wave infrared (SWIR) image sensor with a dual-exposure readout technique, achieving wide dynamic range (WDR) while maintaining a compact pixel design. The proposed dual-exposure readout technique enhances dynamic range (DR) without increasing the integration capacitor of unit pixel, addressing the tradeoff between pixel miniaturization and DR expansion in SWIR image sensors. This method allows the sensor to capture both low- and high-intensity signals, preventing saturation in bright regions while maintaining sensitivity to weak signals. The proposed readout integrated circuit (ROIC), implemented in a 0.18- $\mu $ m CMOS process, features a $128\times 128$ pixel array with a 20- $\mu $ m pixel pitch, utilizing a capacitive transimpedance amplifier (CTIA) front end for enhanced signal fidelity. In addition, the sensor exhibits a low readout noise of 86.83 $\mu $ V ${}_{\mathbf {\textit {rms}}}$ and operates with a power consumption of 42.24 mW, making it suitable for low-power, high-speed SWIR imaging applications. These results confirm that the proposed architecture provides a scalable, power-efficient solution for next-generation SWIR imaging systems.