Method of controlling illumination device based on current-voltage model

The present invention relates to an illumination device comprising a number of LEDs, means for receiving an input signal, means for generating an activation signal for at least one of the LEDs based on the input signal. The illumination device comprises further means for obtaining the voltage across and current through the LED and the means for generating the activation signal is adapted to generate the activating signal based on the voltage, the current and a current- voltage model related to LED. The current-voltage model defines a relationship between the current, the voltage and the colorimetric properties of said light emitted by LED. The present invention relates also to a method of controlling and a meted of calibrating such illumination device.