CIRCUIT FOR DETECTING SATURATION LEVEL OF A IMAGE SENSOR, METHOD FOR DETECTING SATURATION LEVEL OF THE IMAGE SENSOR AND THE IMAGE SENSOR HAVING THE CIRCUIT

摘要

A circuit and a method for detecting a saturation level of an image sensor, and an image sensor with the circuit are provided to accurately detect the saturation level of the image sensor by comparing a voltage signal of a reset level and a voltage signal of the saturation level. A pixel part(345) includes a floating diffusion node(FDN) electrically connected/disconnected to a photo-diode(PD) and outputs a voltage signal corresponding to a voltage of the floating diffusion node. A rest node(RN) is electrically connected or disconnected to the floating diffusion node. A detection control part(343) applies a power supply voltage(VDD) or a reference voltage(GND) to the reset node. The detection control part includes the first rest switch(RTr1) for electrically connecting or disconnecting the rest node and the floating diffusion node, the second rest switch(RTr2) for applying the power supply voltage to the reset node, and a reference voltage switch for applying the reference voltage to the reset node.