Circuit for driving a power switch

1. An electronic circuit comprising:

a first power switch coupled to a second power switch via a switching node;

a driver coupled to the first power switch, wherein the driver comprises an energy storing element coupled to the switching node;

a sensor to sense an electrical parameter of the driver; and

a charger coupled to the sensor and to the energy storing element, the charger being adapted to provide a charge current to charge the energy storage element, and to control the charge current based on the electrical parameter;

wherein the driver is adapted to provide a drive voltage to the first power switch, and wherein the electrical parameter is indicative of the drive voltage;

wherein the driver comprises a first transistor adapted to control the drive voltage; and wherein the sensor comprises a second transistor coupled to a first current source; wherein the second transistor is substantially identical to the first transistor.

2. The electronic circuit as claimed in claim 1 , wherein the electrical parameter comprises at least one of a voltage, a current, a resistance and a temperature.

3. The electronic circuit as claimed in claim 1 , wherein the sensor is adapted to sense the electrical parameter with respect to the switching node.

4. The electronic circuit as claimed in claim 1 , wherein the sensor comprises a comparator adapted to compare a first voltage with a reference voltage, and to generate a control signal to control the charger based on the comparison.

5. The electronic circuit as claimed in claim 4 , wherein the reference voltage is adapted to vary with respect to a voltage at the switching node.

6. The electronic circuit as claimed in claim 4 , wherein the sensor comprises

a third transistor coupled to the second power switch; and

a reference voltage source coupled to the comparator and to the third transistor.

7. The electronic circuit as claimed in claim 1 , wherein the charger comprises a charging switch coupled to a second current source.

8. The electronic circuit as claimed in claim 7 , wherein the charger comprises a second energy storing element coupled to the second current source and to the second power switch.

9. The electronic circuit as claimed in claim 1 , wherein the second power switch is coupled to a ground via a resistance.

10. The Circuit as claimed in claim 1 , wherein the circuit is made at least in part based on a III/V semiconductor.

11. The circuit as claimed in claim 10 , wherein the first power switch is based on the III/V semiconductor.

12. The circuit as claimed in claim 10 , wherein the III/V semiconductor comprises Gallium Nitride.

13. A method of powering a power switch driver adapted to provide a drive voltage, the driver comprising an energy storing element and a first transistor adapted to control the drive voltage, the method comprising

providing a sensor comprising a second transistor coupled to a first current source; wherein the second transistor is substantially identical to the first transistor;

sensing an electrical parameter of the driver, wherein the electrical parameter is indicative of the drive voltage; and

adjusting a current to charge the energy storing element based on the electrical parameter.

14. The method as claimed in claim 13 , wherein the electrical parameter is sensed with respect to a switching node.

15. The method as claimed in claim 13 , comprising comparing the electrical parameter with a reference, and generating a control signal to adjust the current based on the comparison.

16. The method as claimed in claim 15 , wherein the reference is a reference voltage adapted to vary with respect to a voltage at the switching node.