Abstract: A readout circuit, for at least one sensing element, includes an amplifier including an input node for receiving charges from the sensing element or elements and an output node, a first feedback loop comprising a feedback capacitor, and at least one second feedback loop comprising another feedback capacitor, between the output and input nodes of the amplifier, for defining different gains. The at least two feedback capacitors being each connectable to a reference voltage supply via respective switches, for pre-loading the feedback capacitors with a predetermined charge different from the charge obtainable from the at least one sensing element, for sampling signals at a reset level before charge transferal. The loops comprising a respective switch between their capacitors and the output node, for operatively connecting and disconnecting each loop, for obtaining reset voltages at two different gains and signal voltages at two different gains.