A 3T or 4T pixel compatible DR extension technique suitable for 3D-IC imagers: A 800×512 and 5μm pixel pitch 2D demonstrator

In this paper is presented a High Dynamic Range (HDR) extension technique that applies to an imager without modifying any of its other specifications (as speed, noise floor or pixel scheme). The technique relies on the division of the focal plane into blocks that are able to choose the integration time from a set of eleven exposures, reaching +60db extension compared to a standard CMOS imager. The exposure time of each block can also be controlled by an external frame buffer, paving the way to advanced bracketing techniques. This system has been explored with a proof of concept sensor fabricated in a 0.18μm CMOS process.