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

This paper 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 trade-off 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 μm CMOS process, features a 128 × 128 pixel array with a 20 μm pixel pitch, utilizing a capacitive transimpedance amplifier (CTIA) front-end for enhanced signal fidelity. Additionally, the sensor exhibits a low readout noise of 86.83 μV<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> 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.