Patent ID: 7078752

Claim:
A method of controlling a photodetector that comprises: a photodiode having a first electrode connected to an electrical potential reference node, and a second electrode designed to store electrical charge generated in the photodiode; a sensing node; a control circuit; a transfer MOS transistor having a first channel electrode connected to the second electrode of the photodiode, a second channel electrode connected to the sensing node, and a gate electrode connected to the control circuit in order to adjust the electrical potential of a conduction channel extending between the first and second channel electrodes, making it possible to control the transfer of electrical charge from the second electrode of the photodiode to the sensing node; and a reset MOS transistor having a first channel electrode connected to the sensing node, a second channel electrode connected to a first terminal of an electrical potential generator, and a gate electrode, making it possible to control a removal of electrical charge stored on the sensing node to the electrical potential generator, a second terminal of the electrical potential generator being connected to the electrical potential reference node, the photodetector being designed for storing on the second electrode of the photodiode, for transferring and for storing on the sensing node at most a maximum quantity of electrical charge, the electrical potential of the sensing node taking an extreme value when the maximum quantity of electrical charge is stored on the sensing node, the method comprising: at a given instant of electrical charge transfer, the control circuit applying an electrical potential to the gate electrode of the transfer transistor such that the electrical potential of the conduction channel of the transfer transistor has a value equal to the extreme value of the electrical potential of the sensing node multiplied by a number greater than or equal to unity, the electrical potentials being considered relative to the reference node, and wherein, after the given instant of electrical charge transfer, the control circuit causes the electrical potential of the gate electrode of the transfer transistor to vary towards the electrical potential of the reference node over a time longer than the duration of displacement of electrical charge between the conduction channel of the transfer transistor and the sensing node.