A wide dynamic range integrating pixel with an improved low light sensitivity

Digital cameras are increasingly used in emerging applications such as automotive safety. Automotive scenes require the use of WDR image sensors for active safety systems with the goal of avoiding collisions by detecting obstacles. In this paper a one dimensional array of pixels from a 0.35-μm CMOS technology is described that integrates the photocurrent in each pixel for time that depends upon the photocurrent to create a wide dynamic range response. An extra MOSFET functioning as a charge spill gate has been included in a previous four transistor pixel to improve the pixel´s low light sensitivity. A pixel responsivity correction scheme described previously for single pixels was applied to the pixel array to control the logarithmic response.