ACTIVE PIXEL SENSOR WITH FULLY-DEPLETED BURIED PHOTORECEPTOR

摘要

A fully depleted photodiode (200) accumulates charge into both the photodiode (200) and a separate floating diffusion (205). The photodiode (200) is a buried photodiode having two PN junctions for photocarrier conversion. The floating diffusion (205) has less capacitance than the overall photodiode, thereby resulting in a knee-shaped transfer characteristic for charge accumulation that results in a larger dynamic range. The floating diffusion (205) is connected to an output transistor (210). A reset transistor has a gate (206) that is activated to connect the floating diffusion (205) to a diffusion region (208) that is held at VDD to reset the photodiode (200).