A Self-Powered CMOS Active Pixel Sensor Using Serially Connected Photodiodes

S-H Jo, B-S Choi, J. Kim, P. Choi, J-K Shin
Kyungpook National University, KR

Keywords: active pixel sensor, photodiodes, energy harvesting, CMOS image sensor

Summary:

In this work, we propose a self-powered image sensor using serially connected photodiodes for significantly reducing power consumption of the CMOS image sensor (CIS). The proposed self-powered APS is capable of imaging and energy harvesting (EH) on same focal plane without any complex circuit, by using only six transistors. Its pixel size is 10 µm2 (fill factor: 42.5%). The proposed self-powered active pixel sensor (APS) allows to have two operating modes: EH mode for event detection (low-resolution mode) and normal mode for capturing the image of the scene (high-resolution mode). This approach makes the proposed self-powered APS architecture very useful in applications where ultra low-power is required. Simulation results show that the proposed image sensor consumes 4.34 pW/frame-pixel (dynamic and leakage power consumption) and its swing of output voltage is 780 mV without supply voltage. The proposed APS is being fabricated by using 1-poly 6-metal 0.18 μm standard CMOS technology.