Fig. 1. Schematic diagram of the proposed unit pixel.
Fig. 2. Cross-sectional view of the proposed unit pixel.
Fig. 3. Timing diagram for the operation of the proposed method of dynamic range extension.
Fig. 4. Comparison of pixel output voltage characteristics as a function of the light intensity between the conventional mode and the wide dynamic range mode.
Fig. 5. Pixel output voltage characteristics according to power supply voltage of in-pixel CMOS inverter
Fig. 6. Captured images when VREF is (a) 0 V, and (b) 3.3 V.
Fig. 7. Simulation results of pixel output voltage characteristics according to the value of n+/p-sub junction capacitance.
Table 1. Characteristics of the proposed CMOS image sensor.
References
- M. Bigas, E. Cabruja, J. Forest, and J. Salvi, "Review of CMOS image sensors", Microelectron. J., Vol. 37, No. 2, pp. 433-451, 2006. https://doi.org/10.1016/j.mejo.2005.07.002
- E. Fossum, "CMOS image sensors: Electronic camera on a chip", IEEE Trans. Electron Devices, Vol. 44, No. 10, pp. 1689-1698, 1997. https://doi.org/10.1109/16.628824
- M. Bae, B.-S. Choi, S.-H. Jo, H.-H. Lee, P. Choi, and J.-K. Shin, "A Linear-Logarithmic CMOS Image Sensor with Adjustable Dynamic Range", IEEE Sens. J., Vol. 16, No. 13, pp. 5222-5226, 2016. https://doi.org/10.1109/JSEN.2016.2562638
- J. Park, M. Mase, S. Kawahito, M. Sasaki, Y. Wakamori, and Y. Ohta, "A 142dB Dynamic Range CMOS Image Sensor with Multiple Exposure Time Signals", IEEE Asian Solid-State Circuits Conf., pp. 85-88, Hsinchu, Taiwan, 2005.
- D. Seong, B.-S. Choi, S.-H. Kim, J. Lee, and J.-K. Shin "Wide Dynamic Range CMOS Image Sensor with Adjustable Sensitivity Using Cascode MOSFET and Inverter", J. Sens. Sci. Technol., Vol. 27, No. 6, pp. 362-387, 2018. https://doi.org/10.5369/JSST.2018.27.6.362
- B. S. Choi, S. H. Jo, M. Bae, J. Kim, P. Choi, J. K. Shin and Y. Joo, "A Complementary Metal Oxide Semiconductor Image Sensor with Increased Dynamic Range Using Feedback Reset Mechanism", Sensor Letters, Vol.13, No. 8, pp. 658-662, 2015. https://doi.org/10.1166/sl.2015.3479
- K. Nishimura, Y. Sato, J. Hirase, R. Sakaida, M. Yanagida, T. Tamaki, M. Takase, H. Kanehara, M. Murakami, and Y. Inoue, "An over 120dB simultaneous-capture wide-dynamic-range 1.6e- ultra-low-reset-noise organic-photoconductive-film CMOS image sensor", IEEE International Solid-State Circuits Conf., pp. 110-111, San Francisco, US, 2016.
- M. -W. Seo, T. Sawamoto, T. Akahori, T. Iida, T. Takasawa, K. Yasutomi and S. Kawahito, "A Low Noise Wide Dynamic Range CMOS Image Sensor With Low-Noise Transistors and 17b Column-Parallel ADCs", IEEE Sens. J., pp. 2922-2929, 2013.
- J. -B. Chun, H. J. Jung, C. -M. Kyung, "Dynamic-Range Widening in a CMOS Image Sensor Through Exposure Control Over a Dual-Photodiode Pixel", IEEE Trans. Electron Devices, Vol. 56, No. 12, pp. 3000-3008, 2009. https://doi.org/10.1109/TED.2009.2033327
- E. R. Fossum, "Active Pixel Sensors: Are CCD's Dinosaurs?", Proc. of SPIE, pp. 2-14, CA, US, 1993.
- G. P. Weckler, "Operation of p-n Junction Photodetector s in a Photon Flux Integrating Mode", IEEE J. Solid-State Circuits, Vol. 2, No. 3, pp. 65-73, 1967. https://doi.org/10.1109/JSSC.1967.1049795
- R. Jacob, CMOS Circuit Design, Layout, and Simulation, Piscataway, IEEE Press, NJ, pp. 331-352, 1997.