A photodetector including an amorphous silicon photodiode having its anode
connected to a reference voltage, an initialization MOS transistor
connected between the cathode of the photodiode and a first supply voltage
to set the cathode to the first supply voltage during an initialization
phase, and means for measuring the voltage of the photodiode cathode,
including saturation means for bringing the photodiode cathode to a
saturation voltage close to the reference voltage immediately before the
initialization phase.
