Active pixel sensor with coupled gate transfer transistor

Abstract

A complementary metal-oxide semiconductor (CMOS) active pixel sensor includes a photodiode, a transfer transistor with a coupled gate, a reset transistor and a signal transfer circuit, where the photodiode generates electric charges in response to incident light, the transfer transistor transfers the electric charges integrated in the photodiode to a floating diffusion node, wherein the transfer transistor has a first transfer gate and a second transfer gate, and the first and second transfer gates have a coupled gate structure, the reset transistor resets a potential level of the floating diffusion node by a given voltage level, the signal transfer circuit transfers the potential level of the floating diffusion node to an internal circuit in response to a selection signal, and the CMOS active pixel sensor with the coupled gate may increase a capacity of the photodiode and reduce an image lag by using a voltage coupling effect of the coupled gate.