A Low-power CMOS Image Sensor Based on Variable Frame Rate Operation

Abstract

Various circuits and devices are integrated on the CMOS image sensor (CIS) chip. Sources of power consumption in the CIS include source followers of the pixel array, bias circuits, driving circuits, a noise canceller, and readout circuits. In this paper, a low-power complementary metal oxide semiconductor (CMOS) image sensor based on variable frame rate operation is proposed. Power consumption of bias circuits and source followers of the pixel array is reduced by the variable frame rate operation in the proposed CIS. In most cases, the constant bias current continuously flows through the bias circuits and source followers even if the frame rate is changed. However, results indicate that using the variable frame rate operation reduces the constant bias current of the proposed CIS. Results also indicate that the power consumption is reduced by lowering the frame rate without significant image degradation. © 2017, Institute of Electronics Engineers of Korea. All rights reserved.