Current driver for led diodes

A circuit, comprising:

• a first series connection of a first transistor and a first resistance coupled between a supply node and a reference node;
• a second series connection of a second transistor and a second resistance coupled between the supply node and the reference node;
• an operational amplifier having a first output node and a second output node;
• a first switch configured to selectively couple the first output node to a first control terminal of the first transistor;
• a second switch configured to selectively couple the second output node to a second control terminal of the second transistor;
• and
• a clock signal configured to alternately actuate the first and second switches.

A current driver device for an array of LED diodes, said array comprising a plurality of channels, each channel comprising a plurality of series connected LEDs, said current driver device comprising, for each channel, a current driver circuit, each current driver circuit comprising:

• a first series connection of a first transistor and a first resistance,
• a second series connection of a second transistor and a second resistance (Rs2),
• said first and second series connections being arranged in parallel to each other along an electric path between one of said channels and a voltage reference node,
• an operational amplifier, and
• a switch device driven by a clock signal and able to apply at a non-inverting input terminal and inverting input terminal of the operational amplifier alternately a reference voltage and a voltage across the first resistance or the voltage across the second resistance according to a half-period of the clock signal,
• said switch device configured to apply an output signal of the operational amplifier alternately to the first and second transistor according to the half-period of the clock signal,
• a storage element arranged to maintain turned on the first and second transistors when not driven by the output signal of the operational amplifier