Image pixel supporting global shutter and rolling shutter, image sensor including the same, and operating method of image sensor

An image pixel comprising:

• a first photodiode;
• a common circuit including:
• a first transfer transistor configured to transfer charges generated by the first photodiode to a first floating diffusion node;
• a reset transistor and a conversion gain transistor electrically connected in series between a pixel voltage and the first floating diffusion node and configured to share a second floating diffusion node;
• and
• a drive transistor configured to generate an output voltage at a first node in response to a voltage of the first floating diffusion node;
• a sampling circuit including a first capacitor and a second capacitor configured to store the output voltage of the first node;
• and
• a first transistor configured to electrically connect at least one of the first or second capacitors to the second floating diffusion node.

An image sensor comprising:

• a pixel array in which a plurality of image pixels are arranged;
• and
• a mode setting register configured to set an operating mode of the image sensor including the pixel array,
• wherein each of the plurality of image pixels includes:
• a photodiode;
• a common circuit including a floating diffusion node configured to receive charges from the photodiode and configured to transfer an output voltage of a first node based on a voltage of the floating diffusion node;
• a first transistor electrically connected between the first node and a column line;
• a sampling circuit including a second transistor electrically connected between the first node and a second node, a first capacitor, and a second capacitor, wherein the first and second capacitors are electrically connected to the second node;
• a third transistor electrically connected between the second node and the column line;
• and
• a fourth transistor configured to electrically connect the floating diffusion node and the first capacitor, and
• wherein, when the operating mode is a rolling shutter mode, the fourth transistor is configured to transfer charges that overflow from the photodiode to the first capacitor for storage therein.