Patent ID: 8125159

Claim:
A device for driving a light-emitting-diode element, with variable light intensity and having a turning-on threshold voltage, the device comprising: a supply stage having an output to be connected to said light-emitting-diode element, said supply stage being configured so as to have a first operating mode and a second operating mode, wherein, in said first operating mode, said supply stage generates a controlled supply current and, in said second operating mode, said supply stage generates a controlled supply voltage no greater than said turning-on threshold voltage; a current sensor, connectable to said output for generating, in use, a current-feedback signal correlated to the current flowing in said light-emitting-diode element and sent to said supply stage in said first operating mode; and an intensity-control stage generating a mode-control signal sent to said supply stage and controlling sequential switching between said first and second operating modes of said supply stage according to a desired light intensity.