WORKSHOP PAPER
A dual mode PWM based 4T pixel CMOS image sensor for higher dynamic range and low power imaging applications
Prayag Jaysing Wakale1, Rahul Kumar Singh1, Nitin Gupta1, Vibhav Patel2, Mukul Sarkar1
1Indian Institute of Technology, Delhi,
223rdiTech (DV2JS Innovation LLP), Delhi,

Abstract

This paper presents a 4T pixel CMOS image sensor suitable for indoor and outdoor low-power imaging applications. The sensor has two operational modes: low noise (LN) and high dynamic range (HDR). The pixel operates based on a PWM technique and is implemented using a single NMOS as a comparator. In LN mode, the pixel is operated similarly to a 4T pixel, and in HDR mode, it is operated as a 3T. The prototype chip was fabricated in the 180 nm 1P6M CIS process and has a pixel array 128x128. It achieves a noise of 5 e-RMS in LN mode and a dynamic range of more than 100 dB in HDR mode.
Year: 2025
Workshop: IISW
URL: https://doi.org/10.60928/wit7-s1jt
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Keywords

CMOS Image Sensors(CIS), Low Noise (LN), High Dynamic Range (HDR),

References

1) Choi, Jaehyuk and Shin, Jungsoon and Kang, Dongwu and Park, Du-Sik, "Always-On CMOS Image Sensor for Mobile and Wearable Devices", IEEE Journal of Solid-State Circuits, vol. 51, no. 1, pp. 130-140, 2016. https://doi.org/10.1109/JSSC.2015.2470526
2) Cevik, Ismail and Ay, Suat U., "An Ultra-Low Power Energy Harvesting and Imaging (EHI) Type CMOS APS Imager With Self-Power Capability", IEEE Transactions on Circuits and Systems I: Regular Papers, pp. 2177-2186, 2015. https://doi.org/10.1109/TCSI.2015.2451892
3) Park, Injun and Jo, Woojin and Park, Chanmin and Park, Byungchoul and Cheon, Jimin and Chae, Youngcheol, "A 640 × 640 Fully Dynamic CMOS Image Sensor for Always-On Operation", 2020 IEEE Journal of Solid-State Circuits, pp. 898-907, 2020. https://doi.org/10.1109/JSSC.2019.2959486
4) Kim, Sangwoo and Kim, Taehyoung and Seo, Kiwon and Han, Gunhee, "A Fully Digital Time-Mode CMOS Image Sensor with 22.9pJ/frame.pixel and 92dB Dynamic Range", IEEE International Solid-State Circuits Conference (ISSCC), vol. 65, pp. 1-3, 2022. https://doi.org/10.1109/ISSCC42614.2022.9731656
5) S. -H. Kim, Y. Cho, J. Lee, J. -H. Chun and J. Choi, "A 2.03-mW CMOS Image Sensor With an Integrated Four-Stacked Charge-Recycling Driver for Image Signal Transmission", IEEE Access, vol. 10, pp. 99553-99561, 2022. https://doi.org/10.1109/ACCESS.2022.3207298