a current source comprises a current driver comprising a current generator and a first resistor serially coupled at a first node , a level shift unit located between the first node and a second node to generate a rated voltage difference between the second and the first nodes , and a voltage regulator device having an input terminal coupled to the second node and an output terminal coupled to a control terminal of the current generator . the voltage regulator device maintains the voltage level of the second node at a first voltage reference by modifying the voltage level of the control terminal . along with the variation of the voltage level of the control terminal , a supply current generated by the current source for a load is varied to modify the voltage level of the second node to the first voltage level . the control loop stabilizes the supply current value .