Image sensor using a boosting capacitor and a negative bias voltage

An image sensor, comprising:

• a row driver;
• a photodiode connected to a first power node configured to supply a first source voltage, and configured to generate a charge in response to light;
• a transfer transistor connecting the photodiode and a floating diffusion in response to a transmission control signal;
• a reset transistor connected between the floating diffusion and a second power node configured to supply a second source voltage that is higher than the first source voltage;
• a boosting capacitor connected directly to the floating diffusion and a control node where a boosting control signal is input, and configured to adjust a capacity of the floating diffusion in response to the boosting control signal;
• and
• a bias circuit having a first current circuit and a second current circuit configured to supply different bias currents to an output node to which a voltage signal corresponding to a charge accumulated in the floating diffusion is output,
• wherein the control node is different from the first power node,
• wherein the first current circuit and the second current circuit are configured to simultaneously provide a first bias current and a second bias current to the output node during a first time, respectively,
• wherein the row driver is configured to:
• decrease the boosting control signal from a high level to a low level after turning off the transfer transistor;
• and
• switch the reset transistor from a turned on state to a turned off state during the first time,
• wherein the second current circuit is further configured to provide the second bias current to the output node during a second time,
• wherein the row driver is further configured to switch the transfer transistor from a turned on state to a turned off state during the second time, and
• wherein the second time is different from the first time.