Image sensor, camera module including image sensor, and operating method of image sensor

A camera module, comprising:

• an image sensor configured to generate image data;
• and
• a logic circuit configured to generate calibrated image data based on calibrating the image data received from the image sensor,
• wherein the image sensor includes
• a pixel array including a plurality of pixels, wherein each pixel of the plurality of pixels includes
• a photodiode,
• a transfer gate transistor between the photodiode and a floating diffusion node, and
• a first transistor between the floating diffusion node and a first voltage node, wherein the first voltage node is configured to receive a first voltage,
• a row driver connected with rows of the plurality of pixels through row lines, wherein, when a readout operation is performed on pixels of a selected row among the rows, for each pixel of the pixels of the selected row among the rows, the row driver is configured to:
• apply a second voltage to a gate of the first transistor, and
• turn on the transfer gate transistor such that electrons integrated in the photodiode are dumped to the floating diffusion node;
• and
• an analog-to-digital conversion circuit connected with columns of the plurality of pixels through column lines, the analog-to-digital conversion circuit configured to detect pixel values from the pixels of the selected row,
• wherein, for each pixel of the pixels of the selected row, the first transistor is configured to be set to a quasi-on state while the transfer gate transistor is turned on.

An operating method of an image sensor which includes a plurality of pixels, the plurality of pixels including rows of pixels, wherein each pixel of the plurality of pixels includes a photodiode, a transfer gate transistor between the photodiode and a floating diffusion node, and a first transistor between the floating diffusion node and a first voltage node, the first voltage node configured to receive a first voltage, the operating method comprising:

• for each pixel of pixels belonging to a selected row from among the rows of pixels, applying a second voltage to a gate of the first transistor;
• turning on the transfer gate transistor;
• and
• applying a clamp voltage, which is lower than the first voltage and the second voltage and is higher than a ground voltage, to the gate of the first transistor, while the transfer gate transistor is turned on.