Abstract: In an image sensor, a front-end circuit provides an output signal indicative of the amount of light in response to at least one input signal. The front-end circuit includes a transistor having a threshold voltage that affects a relationship between the output signal and the level of the detection quantity. This transistor has a biasing node via which a biasing voltage can be applied to a semiconductor region that affects the threshold voltage of the transistor. A replica of the front-end circuit receives at least one defined input signal, among which is a substitute of the detection quantity having a defined level. The replica is arranged in a control loop that controls the biasing voltage that is applied to the biasing node in the replica, so that the replica provides a defined output signal. This biasing voltage is then also applied to the biasing node in the front-end circuit.

Abstract: In an image sensor, a photo detector circuit applies a photo current to a capacitive node during a photo detection time interval. A front-end circuit comprises an input transistor having a control node that is coupled to the capacitive node. A switchable biasing arrangement puts the input transistor in a disabled state during the photo detection time interval. The input transistor is put in an enabled state after the photo detection time interval. This then causes the front-end circuit to provide an output signal that is representative of a voltage on the capacitive node after the photo detection time interval.

Abstract: In an image sensor, a photo detector circuit applies a photo current to a capacitive node during a photo detection time interval. A front-end circuit comprises an input transistor having a control node that is coupled to the capacitive node. A switchable biasing arrangement puts the input transistor in a disabled state during the photo detection time interval. The input transistor is put in an enabled state after the photo detection time interval. This then causes the front-end circuit to provide an output signal that is representative of a voltage on the capacitive node after the photo detection time interval.

Abstract: In an image sensor, a front-end circuit provides an output signal indicative of the amount of light in response to at least one input signal. The front-end circuit includes a transistor having a threshold voltage that affects a relationship between the output signal and the level of the detection quantity. This transistor has a biasing node via which a biasing voltage can be applied to a semiconductor region that affects the threshold voltage of the transistor. A replica of the front-end circuit receives at least one defined input signal, among which is a substitute of the detection quantity having a defined level. The replica is arranged in a control loop that controls the biasing voltage that is applied to the biasing node in the replica, so that the replica provides a defined output signal. This biasing voltage is then also applied to the biasing node in the front- end circuit.