Linear-logarithmic Active Pixel Sensor with Photogate for Wide Dynamic Range CMOS Image Sensor
2
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
This paper proposes a novel complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) and presents its performancecharacteristics. The proposed APS exhibits a linear-logarithmic response, which is simulated using a standard 0.35-μm CMOSprocess. To maintain high sensitivity and improve the dynamic range (DR) of the proposed APS at low and high-intensity light, respectively,two additional nMOSFETs are integrated into the structure of the proposed APS, along with a photogate. The applied photogatevoltage reduces the sensitivity of the proposed APS in the linear response regime. Thus, the conversion gain of the proposed APSchanges from high to low owing to the addition of the capacitance of the photogate to that of the sensing node. Under high-intensitylight, the integrated MOSFETs serve as voltage-light dependent active loads and are responsible for logarithmic compression. The DRof the proposed APS can be improved on the basis of the logarithmic response. Furthermore, the reference voltages enable the tuningof the sensitivity of the photodetector, as well as the DR of the APS.
Abstract
This paper proposes a novel complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) and presents its performancecharacteristics. The proposed APS exhibits a linear-logarithmic response, which is simulated using a standard 0.35-μm CMOSprocess. To maintain high sensitivity and improve the dynamic range (DR) of the proposed APS at low and high-intensity light, respectively,two additional nMOSFETs are integrated into the structure of the proposed APS, along with a photogate. The applied photogatevoltage reduces the sensitivity of the proposed APS in the linear response regime. Thus, the conversion gain of the proposed APSchanges from high to low owing to the addition of the capacitance of the photogate to that of the sensing node. Under high-intensitylight, the integrated MOSFETs serve as voltage-light dependent active loads and are responsible for logarithmic compression. The DRof the proposed APS can be improved on the basis of the logarithmic response. Furthermore, the reference voltages enable the tuningof the sensitivity of the photodetector, as well as the DR of the APS.
참고문헌 (11)
- H. Abe, "Device technologies for high quality and smaller pixel in CCD and CMOS image sensors", IEDM Tech. Dig., pp.989~992 (2004)
- K. Mabuchi, "CMOS image sensors comprised of floating diffusion driving pixels with buried photodiode", IEEE Journal of Solid-State Circuits, 39(12), pp.2408~2416 (2004)
- H. Takahashi, "A 3. 9-μm pixel pitch VGA format 10-b digital output CMOS image sensor with 1. 5 transistor", pixel, 2004, pp.39(12), 2417~2425
- M. Ikebe, "A Wide-Dynamic-Range Compression Image Sensor With Negative-Feedback Resetting", IEEE Sensors Journal, 7(5), pp.897~904 (2007)
- G. G. Storm, "Combined linear-logarithmic CMOS image sensor", IEEE ISSCC Dig. Tech., pp.112~116 (2004)
- T. Yamada, "A 140dBDynamic-Range MOS Image Sensor with In-Pixel Multiple-Exposure Synthesis", IEEE ISSCC Dig. Tech., pp, pp.50~51 (2008)
- N. Akahane, "A 200dB Dynamic Range Iris-less CMOS Image Sensor with Lateral Overflow Integration Capacitor using Hybrid Voltage and Current Readout Operation", IEEE ISSCC Dig. Tech., pp.1161~1170 (2006)
- T. H. Hsu, "An effective method to improve the sensitivity of deep submicrometer CMOS image sensors", IEEE Electron Device Letters, 26, pp.547~549 (2005)
- Y. Chae, "Sensitivity controllable CMOS image sensor pixel using control gate overlaid on photodiode", IEEE Electron Device Letters, 28, pp.495~498 (2007)
- 배명한, "A Wide Dynamic Range CMOS Image Sensor Based on a Pseudo 3-Transistor Active Pixel Sensor Using Feedback Structure", 센서학회지, 21(6), pp.413~419 (2012), 한국센서학회[DOI]
- M. Sasaki, "A wide-dynamic-range CMOS image sensor based on multiple short exposure-time readout with multiple-resolution column-parallel ADC", IEEE Sensors Journal, 7(1), pp.151~158 (2007)