A 140 dB Single-Exposure Dynamic-Range CMOS Image Sensor with In-Pixel DRAM Capacitor

Abstract

This paper presents a CMOS image sensor with a $2.1\ \mu \mathrm{m}$ pixel for automotive applications. By using a sub-pixel structure and a high-capacity DRAM capacitor per pixel, a single exposure dynamic range achieves 140 dB at $85 ^{\circ}\mathrm{C}$, supporting LED flicker mitigation. Dual conversion gain circuits of a small photodiode enable SNR to stay above 23 dB at $105 ^{\circ}\mathrm{C}$ even with the very high capacitance. The full-depth deep trench isolation prevents electrical crosstalk between pixels even in extremely high illuminance conditions and achieves high conversion gain for low random noise of 0.83 e-.