Gate drivers for circuits based on semiconductor devices
An electronic component includes a switching device comprising a source, a gate, and a drain, the switching device having a predetermined device switching rate. The electronic component further includes a gate driver electrically connected to the gate and coupled between the source and the gate of the switching device, the gate driver configured to switch a gate voltage of the switching device at a gate driver switching rate. The gate driver is configured such that in operation, an output current of the gate driver cannot exceed a first current level, wherein the first current level is sufficiently small to provide a switching rate of the switching device in operation to be less than the predetermined device switching rate.
1. An electronic component, comprising:
a switching device comprising a source, a gate, and a drain, the switching device having a predetermined device switching rate;
a gate driver electrically coupled between the source and the gate of the switching device; and
a ferrite bead connected between the output of the gate driver and the gate of the switching device, the gate driver configured to switch a gate voltage of the switching device at a gate driver switching rate, the gate driver configured such that in operation, an output current of the gate driver cannot exceed a first current level; wherein
the first current level is sufficiently small to provide a switching rate of the switching device in operation to be less than the predetermined device switching rate.
2. The electronic component of claim 1 , wherein the electronic component is part of a half bridge circuit.
3. The electronic component of claim 1 , wherein the switching device comprises a III-Nitride transistor.
4. The electronic component of claim 1 , the switching device comprises an enhancement-mode transistor coupled to a depletion-mode transistor.
5. The electronic component of claim 4 , wherein the depletion-mode transistor and the enhancement-mode transistor are configured such that a source of the enhancement-mode transistor serves as the source of the switching device, a gate of the enhancement-mode transistor serves as the gate of the switching device, and a drain of the depletion-mode transistor serves as a gate of the switching device.
6. The electronic component of claim 1 , wherein the switching device is operable to block at least 300V when biased OFF.
7. The electronic component of claim 6 , wherein a maximum rated current of the switching device is at least 50 Amps.
8. The electronic component of claim 6 , wherein a ratio of the first current level to a maximum rated current of the switching device is less than 1/100.
9. The electronic component of claim 1 , wherein the switching rate of the switching device in operation is less than 0.5 times the predetermined device switching rate.
10. An electronic component, comprising:
a switching device comprising a source, a gate, and a drain, the switching device being operable to block at least 300V when biased OFF;
a gate driver coupled between the source and the gate of the switching device; and
a ferrite bead connected between the output of the gate driver and the gate of the switching device; wherein
the gate driver is configured to switch voltage at an output of the gate driver at a gate driver switching rate, a resistance between the output of the gate driver and the gate of the switching device is less than 5 Ohms, and the gate driver is configured such that in operation, an output current of the gate driver is limited by circuitry of the gate driver such that the output current cannot exceed a first current level; and
a ratio of the first current level to a maximum rated current of the switching device is less than 1/100.
11. The electronic component of claim 10 , wherein the switching device comprises a III-Nitride transistor.
12. The electronic component of claim 10 , wherein the electronic component is part of a half bridge circuit.
13. The electronic component of claim 10 , wherein the output of the gate driver is directly connected to the gate of the switching device.
14. A method of operating an electronic component, the electronic component comprising:
a switching device comprising a source, a gate, and a drain, the switching device configured to have a predetermined device current switching rate;
a gate driver coupled between the source and the gate of the switching device; and
a ferrite bead connected between the output of the gate driver and the gate of the switching device, the method comprising:
causing the gate driver to switch an output voltage of the gate driver from a first state to a second state at a gate driver switching rate, whereby a gate voltage of the switching device is switched at substantially the same rate as the gate driver switching rate; wherein
switching of the output voltage of the gate driver from the first state to the second state causes current through the switching device to be switched at a current switching rate less than the predetermined device current switching rate.
15. The method of claim 14 , wherein an output of the gate driver is electrically connected to the gate, and switching the output voltage of the gate driver from the first state to the second state causes a voltage of at least 300V to be switched across the switching device.
16. The method of claim 14 , wherein a maximum output current of the gate driver is sufficiently small to cause the current switching rate of the switching device to be less than the predetermined device current switching rate.
17. A circuit, comprising:
a switching device having a maximum rated current and comprising a source, a gate, and a drain;
a first voltage supply which applies an output voltage of at least 300 Volts;
a gate driver connected to a second voltage supply and coupled between the source and the gate of the switching device; and
a ferrite bead between an output of the gate driver and the gate of the switching device, the gate driver configured to switch a gate voltage of the switching device at a gate driver switching rate, the gate driver configured such that in operation, an output current of the gate driver cannot exceed a first current level; wherein
the switching device is configured to block the output voltage applied by the first voltage supply during at least a portion of operation of the circuit;
a ratio of the first current level to the maximum rated current of the switching device is less than 1/100; and
in operation of the circuit, a voltage switching rate of the switching device is greater than 100 Volts/nanosecond.
18. The circuit of claim 17 , wherein the circuit is a half bridge.
19. The circuit of claim 18 , the half bridge being connected to an inductive load, wherein in operation, a current greater than 1 Amp passes through the inductive load.
20. The circuit of claim 17 , wherein the second voltage supply applies an output voltage that is substantially less than the output voltage of the first voltage supply.
21. The circuit of claim 20 , wherein the second voltage supply applies an output voltage less than 25 Volts.
22. The circuit of claim 17 , wherein an output of the gate driver is electrically connected to the gate of the switching device.
23. The circuit of claim 17 , further comprising a resistor between an output of the gate driver and the gate of the switching device, wherein the resistor has a resistance between 0 Ohms and 5 Ohms.
24. The circuit of claim 17 , wherein the switching device comprises a III-Nitride transistor.
25. The circuit of claim 24 , wherein the III-Nitride transistor is a depletion-mode transistor, and the switching device further comprises an enhancement-mode transistor coupled to the III-Nitride transistor.
26. The circuit of claim 17 , wherein in operation of the circuit, voltage blocked by the switching device does not exceed 1.5 times the output voltage of the first voltage supply.
27. The circuit of claim 17 , wherein in operation of the circuit, voltage blocked by the switching device does not exceed 1.2 times the output voltage of the first voltage supply.