A 132dB-Dynamic-Range Global-Shutter Stacked Architecture for High-Performance Imagers

This brief presents a global-shutter imager readout architecture that allows a dynamic range (DR) of more than 132 dB and a high frame rate. It is based on a stacked technology where the top tier contains the back-illuminated pixel array, and the bottom tier contains the subpixel logic array, which implements the dynamic-range extension by selecting the best integration time for each pixel. Experimental results of a 64 $times$ 64 subpixel array confirm the effectiveness of the proposed method in extending the DR by more than 10 bits. The application of the algorithm to higher array resolutions compromises its effectiveness given the increased column capacitance. As a way out, we propose a novel source-follower-based buffer that reduces the settling time of the subpixel without increasing its size. The performed analysis shows that the sensor can reach 1900 and 375 fps, respectively, at full HD and at 8-K resolutions.