Cevik Ismail, Huang Xiwei, Yu Hao, Yan Mei, Ay Suat U
Department of Electrical and Computer Engineering, University Idaho, 875 Perimeter Drive MS 1023 Moscow, ID 83844-1023, USA.
School of Electronics and Information, Hangzhou Dianzi University, No.1 Avenue, 2 Xiasha, Hangzhou 310018, China.
Sensors (Basel). 2015 Mar 6;15(3):5531-54. doi: 10.3390/s150305531.
An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability is introduced in this paper. The photodiode pixel array can not only capture images but also harvest solar energy. As such, the CMOS image sensor chip is able to switch between imaging and harvesting modes towards self-power operation. Moreover, an on-chip maximum power point tracking (MPPT)-based power management system (PMS) is designed for the dual-mode image sensor to further improve the energy efficiency. A new isolated P-well energy harvesting and imaging (EHI) pixel with very high fill factor is introduced. Several ultra-low power design techniques such as reset and select boosting techniques have been utilized to maintain a wide pixel dynamic range. The chip was designed and fabricated in a 1.8 V, 1P6M 0.18 µm CMOS process. Total power consumption of the imager is 6.53 µW for a 96 × 96 pixel array with 1 V supply and 5 fps frame rate. Up to 30 μW of power could be generated by the new EHI pixels. The PMS is capable of providing 3× the power required during imaging mode with 50% efficiency allowing energy autonomous operation with a 72.5% duty cycle.
本文介绍了一种具有片上能量收集和电源管理能力的超低功耗CMOS图像传感器。光电二极管像素阵列不仅可以捕获图像，还能收集太阳能。因此，该CMOS图像传感器芯片能够在成像和收集模式之间切换，实现自供电运行。此外，还为该双模图像传感器设计了一种基于片上最大功率点跟踪（MPPT）的电源管理系统（PMS），以进一步提高能源效率。引入了一种具有非常高填充因子的新型隔离P阱能量收集与成像（EHI）像素。采用了复位和选择升压技术等几种超低功耗设计技术，以保持较宽的像素动态范围。该芯片采用1.8V、1P6M 0.18μm CMOS工艺设计和制造。对于一个96×96像素阵列，在1V电源电压和5fps帧率下，成像器的总功耗为6.53μW。新型EHI像素能够产生高达30μW的功率。该PMS能够以50%的效率提供成像模式所需功率的3倍，实现占空比为72.5%的能量自主运行。
