Driver circuit and method for controlling a switching element

1. A driver circuit for controlling a switching element, the driver circuit comprising:

a plurality of bootstrap capacitors;

a switching unit; and

a control unit which is configured to control the switching unit in dependence of a control signal to

provide a parallel arrangement of the plurality of bootstrap capacitors between a charging voltage and a reference voltage, for charging the plurality of bootstrap capacitors during a charging phase; and

provide a serial arrangement of the plurality of bootstrap capacitors between the charging voltage and a control port of the switching element, for controlling the switching element during a control phase.

2. The driver circuit of claim 1 , wherein the control unit is configured to control the switching unit to

provide the parallel arrangement of the plurality of bootstrap capacitors, if the control signal indicates that the switching element is to be open; and

provide the serial arrangement of the plurality of bootstrap capacitors, if the control signal indicates that the switching element is to be closed.

3. The driver circuit of claim 1 , wherein:

the driver circuit further comprises a basic bootstrap capacitor which is arranged between the charging voltage and the reference voltage during the charging phase and during the control phase, in particular which is arranged permanently between the charging voltage and the reference voltage; and

the basic bootstrap capacitor is configured to supply the control unit with electrical energy for operation of the control unit.

4. The driver circuit of claim 1 , wherein the driver circuit is configured such that

the individual bootstrap capacitors of the plurality of bootstrap capacitors are each charged to a capacitor voltage level during the charging phase with the parallel arrangement of the plurality of bootstrap capacitors; wherein the capacitor voltage level is smaller than the charging voltage; and

a control voltage for controlling the switching element, which is provided during the control phase by the serial arrangement of the plurality of bootstrap capacitors, is higher than the charging voltage.

5. The driver circuit of claim 1 , wherein:

the driver circuit is configured to provide a control voltage to the control port of the switching element during the control phase, using the serial arrangement of the plurality of bootstrap capacitors;

the control port is a gate of the switching element; and

the control voltage is a gate-source voltage.

6. The driver circuit of claim 1 , wherein the plurality of bootstrap capacitors comprises two or more, in particular three or more, bootstrap capacitors.

7. The driver circuit of claim 1 , wherein the reference voltage is different, in particular lower, during the charging phase with the parallel arrangement of the plurality of bootstrap capacitors than during the control phase with the serial arrangement of the plurality of bootstrap capacitors.

8. The driver circuit of claim 1 , wherein the switching unit comprises:

one or more inverters; and/or

one or more switches.

9. The driver circuit of claim 1 , wherein a capacitance of the individual bootstrap capacitors of the plurality of bootstrap capacitors is substantially equal.

10. The driver circuit of claim 1 , wherein:

the control unit is configured to control the switching unit to operate the plurality of bootstrap capacitors in a sequence of switching cycles; and

a, in particular each, switching cycle comprises a charging phase and a subsequent control phase, in particular exactly one charging phase and exactly one subsequent control phase.

11. A power converter comprising:

a switching element; and

a driver circuit according to claim 1 for controlling the switching element.

12. The power converter of claim 11 , wherein:

the switching element is arranged between a first terminal node and a switch node of the power converter;

the switch node exhibits a reference voltage which varies between a first potential of the first terminal node and a second potential of a second terminal node of the power converter; and

the driver circuit is configured to control the switching unit to arrange the parallel arrangement of the plurality of bootstrap capacitors between the charging voltage and the switch node during the charging phase.

13. The power converter of claim 11 , wherein:

the switching element is a high-side switching element of the power converter; and/or

the switching element is an n-type metal oxide semiconductor field effect transistor.

14. A method for controlling a switching element using a plurality of bootstrap capacitors, the method comprising:

providing a parallel arrangement of the plurality of bootstrap capacitors between a charging voltage and a reference voltage, for charging the plurality of bootstrap capacitors during a charging phase; and

providing a serial arrangement of the plurality of bootstrap capacitors between the charging voltage and a control port of the switching element, for controlling the switching element during a control phase.