A Low-Voltage Wide Swing Image Sensor with Simultaneous Energy Harvesting and Imaging Modes
Abstract
This paper proposes a CMOS image sensor that can achieves imaging and energy harvesting simultaneously without introducing additional P-N junctions in the pirel array. The proposed pixel utilizes the vertical N+P-well/DNW/P-sub structures as photodiodes based on a standard 180 nm CMOS mixed-signal process. The N+/P-well is used for imaging, while the P-well/DNW and DNW/P-sub are used for energy harvesting with shorting P-well and P-sub together. Moreover, the traditional 4-T pirel has been improved by using CMOS pairs as the switches and zero-threshold NMOS as the source follower. The rail-to-rail pixel output swing can be achieved. Simulation results show that the dynamic range is increased by 13.4 dB compared with the traditional 4-T pirel. Single pixel occupies an area of 11×13 mm^2 with a fill factor of 72%. An image sensor with 32×32 proposed pixel array and a dual-channel PWM quantizer is designed. Simulation results show that the average power consumption of the image sensor is approximately 6.7 μW@2 MHz.
Zhipeng Li
PhD Student
My research interests include circuit design of image sensors and energy harvesting circuits.
Jian Guan
PhD Student
My research interests include the design of solar cells and energy harvesting circuits.
Haoning Sun
Master’s Student
My research interests include circuit design of analog to digital converter for biomedical applications and noise shaping SAR ADC.
Wenji Mo
Master’s Student
My research interests include circuit design of low-power RISC-V processors and self-powered SoCs.
Jingjing Liu
Associate Professor
My research interests include low-power smart micro-sensor integrated circuit design, image sensors, biomedical sensors, and energy harvesting circuits.