Image sensing device and electronic device comprising the same

An image sensing device comprising:

• a pixel circuit including a floating diffusion, a photoelectric element, a drive transistor, a DCG (Dual Conversion Gain) transistor, a selection transistor, a column line connected to the selection transistor,
• the floating diffusion being a region of the pixel circuit,
• the floating diffusion being configured to store an electric charge generated by the photoelectric element,
• the drive transistor being configured to generate a pixel signal based on the electric charge stored in the floating diffusion,
• the selection transistor being configured to output the pixel signal generated by the drive transistor to the column line in response to the selection transistor receiving a selection signal,
• the selection transistor being configured to output a first pixel signal to the column line based on the electric charge stored in the floating diffusion in a state in which the DCG transistor is turned off,
• the DCG transistor being configured to change a capacitance of the floating diffusion in response to the DCG transistor receiving a gain control signal, and
• the pixel circuit being configured to perform an operation of the selection transistor outputting the first pixel signal to the column line and the DCG transistor receiving, the gain control signal while the selection transistor receives the selection signal maintained at a first level, wherein
• the pixel circuit further includes a reset transistor and a capacitor,
• the reset transistor is configured to provide a reset voltage to the floating diffusion in response to a reset signal,
• the capacitor is connected between the reset transistor and the DCG transistor,
• the DCG transistor is configured to change the capacitance of the floating diffusion using the capacitor,
• the pixel circuit further includes an OR gate, and
• the OR gate is configured to receive the gain control signal and the reset signal, perform an OR calculation based on the gain control signal and the reset signal, and provide a result of the OR calculation to the DCG transistor.

An image sensing device comprising:

• a pixel circuit configured to output a pixel signal in response to a selection signal;
• and
• a readout circuit configured to output a digital signal corresponding to the pixel signal provided from the pixel circuit,
• the readout circuit being configured to receive a first pixel signal from the pixel circuit, generate a gain control signal based on the first pixel signal, and provide the gain control signal to the pixel circuit,
• the readout circuit being configured to receive a second pixel signal output by the pixel circuit using the gain control signal, and output a digital signal corresponding to the second pixel signal, and
• a row driver configured to provide the selection signal to the pixel circuit while maintaining the selection signal at a first level during an operation in which the readout circuit provides the gain control signal to the pixel circuit and an operation in which the pixel circuit outputs the second pixel signal to the readout circuit are performed.