IP Library Granted Patent US 12,640,732
Granted Patent B2
US 12,640,732 · App. 18/668,825 · Granted May 26, 2026

Semiconductor switch

Inventors: Florin Udrea (Cambridge, GB); John William Findlay (Cambridge, GB)
Assignee: CAMBRIDGE GAN DEVICES LIMITED
H03K17/567H03K17/687H03K2217/0063
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Quick Facts
Patent No.
US 12,640,732
App. No.
18/668,825
Granted
May 26, 2026
Kind
B2
Abstract

A semiconductor switch comprising a high-electron-mobility transistor (HEMT) (e.g. a III-nitride HEMT). The semiconductor switch may be a combined switch also comprising a high voltage transistor device such as an insulated-gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a superjunction. The high voltage transistor device may be a silicon or silicon carbide device.

Claims (74)

1 . A semiconductor switch comprising a first main terminal, a second main terminal, and a control terminal, the semiconductor switch comprising:

at least one high voltage HEMT, the high voltage HEMT comprising a high voltage HEMT source terminal, a high voltage HEMT drain terminal, and a high voltage HEMT gate terminal; and

at least one high voltage transistor device, the high voltage transistor device comprising a transistor device first terminal, a transistor device second terminal, and a transistor device gate terminal;

wherein the high voltage HEMT source terminal and the transistor device first terminal are operatively connected to the first main terminal;

wherein the high voltage HEMT drain terminal and the transistor device second terminal are operatively connected to the second main terminal; and

wherein the high voltage HEMT gate terminal is operatively connected to the control terminal;

wherein the control terminal is operatively connected to a first driver output of a driver, and wherein the transistor device gate terminal is operatively connected to a second driver output of the driver; and

wherein the control terminal is configured to be driven, by the driver via the first driver output, within a first driving voltage range; and

wherein the transistor device gate terminal is configured to be driven, by the driver via the second driver output, within a second driving voltage range;

wherein the control terminal is further operatively connected to a third driver output of the driver, wherein:

when the semiconductor switch is in the turn-off mode, the control terminal is configured to selectably receive either:

a regular turn-off signal comprising a first driving voltage level within the first driving voltage range, from the driver via the first driver output; or

a delayed turn-off signal, or a slower turn-off signal, comprising a third driving voltage level within the first driving voltage range, from the driver via the third driver output.

2 . The semiconductor switch according to claim 1 , wherein voltage levels within at least one of the first driving voltage range and the second driving voltage range are configured to vary selectably in time, corresponding to the semiconductor switch being selectably in an on-state mode, an off-state mode, a turn-on mode, or the turn-off mode.

3 . The semiconductor switch according to claim 1 , wherein a slew rate at the control terminal and/or the transistor device gate terminal are configured to vary selectably, corresponding to the semiconductor switch being selectably in a turn-on mode or the turn-off mode.

4 . The semiconductor switch according to claim 1 , further comprising an interface circuit, wherein the high voltage HEMT gate terminal is operatively connected to the control terminal via the interface circuit, wherein the interface circuit is configurable to adjust voltage levels within the first driving voltage range to be operatively compatible with the high voltage HEMT gate terminal.

5 . The semiconductor switch according to claim 2 , further comprising a feedback circuit comprising at least one output operatively connected to a driver feedback input; and wherein the feedback circuit is configured to provide a feedback signal to the driver feedback input, the feedback signal corresponding to a sensed current, a sensed voltage, and/or a sensed temperature in the semiconductor switch.

6 . The semiconductor switch according to claim 4 , wherein the interface circuit comprises a Miller clamp transistor, the Miller clamp transistor comprising a plurality of Miller clamp gates, wherein the interface circuit is configured such that an on-state resistance of the Miller clamp transistor depends on which Miller clamp gate(s) of the plurality of Miller clamp gates is active.

7 . The semiconductor switch according to claim 4 , wherein the interface circuit comprises a plurality of Miller clamp transistors having different on-state resistances, wherein the interface circuit further comprises a logic circuit configured to control activation of each Miller clamp transistor of the plurality of Miller clamp transistors.

8 . The semiconductor switch according to claim 4 , wherein the transistor device gate terminal is operatively connected to the second driver output via the interface circuit.

9 . The semiconductor switch according to claim 1 , wherein the control terminal is operatively connected to the first driver output via a first resistor, or via a first resistor in series with a first diode, and wherein the control terminal is operatively connected to the third driver output via a third resistor, wherein a resistance of the third resistor is greater than a resistance of the first resistor.

10 . The semiconductor switch according to claim 1 , comprising a first Miller clamp transistor and a second Miller clamp transistor, the first Miller clamp transistor and the second Miller clamp transistor being operatively connected to the High voltage HEMT gate terminal, the second Miller clamp transistor having a higher on-state resistance than the first Miller clamp transistor;

wherein the regular turn-off signal is configured to activate the first Miller clamp transistor;

and

wherein the delayed turn-off signal, or the slower turn-off signal, is configured to activate the second Miller clamp transistor.

11 . The semiconductor switch according to claim 4 , wherein the interface circuit comprises a third Miller clamp transistor, the third Miller clamp transistor comprising a third Miller clamp drain terminal, wherein the third Miller clamp drain terminal is operatively connected to the high voltage HEMT gate terminal.

12 . The semiconductor switch according to claim 11 , wherein the interface circuit further comprises a fourth Miller clamp transistor, the fourth Miller clamp transistor comprising a fourth Miller clamp drain terminal, wherein the fourth Miller clamp drain terminal is operatively connected to the transistor device gate terminal.

13 . A method of operating a semiconductor switch, the semiconductor switch comprising a first main terminal, a second main terminal, and a control terminal, the semiconductor switch comprising:

a high voltage HEMT, the high voltage HEMT comprising a high voltage HEMT source terminal, a high voltage HEMT drain terminal, and a high voltage HEMT gate terminal; and

a high voltage transistor device, the high voltage transistor device comprising a transistor device first terminal, a transistor device second terminal, and a transistor device gate terminal;

wherein the high voltage HEMT source terminal and the transistor device first terminal are operatively connected to the first main terminal; and

wherein the high voltage HEMT drain terminal and the transistor device second terminal are operatively connected to the second main terminal;

wherein the method comprises:

driving the control terminal, by a driver via a first driver output, within a first driving voltage range; and

driving the transistor device gate terminal, by the driver via a second driver output, within a second driving voltage range;

wherein the control terminal is further operatively connected to a third driver output of the driver, and wherein the method further comprises:

when the semiconductor switch is in a turn-off mode, providing to the control terminal by a third driver output of the driver to selectably receive either:

a regular turn-off signal comprising a first driving voltage level within the first driving voltage range, from the driver via the first driver output; or

a delayed turn-off signal, or a slower turn-off signal, comprising a third driving voltage level within the first driving voltage range, from the driver via the third driver output.

14 . The semiconductor switch according to claim 4 , comprising a feedback circuit comprising at least one output operatively connected to the interface circuit, wherein the feedback circuit is configured to provide a feedback signal to the interface circuit, the feedback signal corresponding to a sensed current, a sensed voltage, and/or a sensed temperature in the semiconductor switch.

15 . A semiconductor switch comprising a first main terminal, a second main terminal, and a control terminal, the semiconductor switch comprising:

at least one high voltage HEMT, the high voltage HEMT comprising a high voltage HEMT source terminal, a high voltage HEMT drain terminal, and a high voltage HEMT gate terminal; and

at least one high voltage transistor device, the high voltage transistor device comprising a transistor device first terminal, a transistor device second terminal, and a transistor device gate terminal;

wherein the high voltage HEMT source terminal and the transistor device first terminal are operatively connected to the first main terminal;

wherein the high voltage HEMT drain terminal and the transistor device second terminal are operatively connected to the second main terminal; and

wherein the high voltage HEMT gate terminal is operatively connected to the control terminal;

wherein the control terminal is operatively connected to a first driver output of a driver, and wherein the transistor device gate terminal is operatively connected to a second driver output of a driver; and

wherein the control terminal is configured to be driven, by the driver via the first driver output, within a first driving voltage range; and

wherein the transistor device gate terminal is configured to be driven, by the driver via the second driver output, within a second driving voltage range;

wherein the transistor device gate terminal is operatively connected to a fourth driver output of the driver, wherein:

when the semiconductor switch is in a turn-off mode, the transistor device gate terminal is configured to selectably receive either:

a regular turn-off signal comprising a second driving voltage level within the second driving voltage range, from the driver via the second driver output; or

a delayed turn-off signal, or a slower turn-off signal, comprising a fourth driving voltage level within the second driving voltage range, from the driver via the fourth driver output.

16 . The semiconductor switch according to claim 15 , wherein voltage levels within at least one of the first driving voltage range and the second driving voltage range are configured to vary selectably in time, corresponding to the semiconductor switch being selectably in an on-state mode, an off-state mode, a turn-on mode, or the turn-off mode.

17 . The semiconductor switch according to claim 15 , wherein a slew rate at the control terminal and/or the transistor device gate terminal are configured to vary selectably, corresponding to the semiconductor switch being selectably in a turn-on mode or the turn-off mode.

18 . The semiconductor switch according to claim 15 , further comprising an interface circuit, wherein the high voltage HEMT gate terminal is operatively connected to the control terminal via the interface circuit, wherein the interface circuit is configurable to adjust voltage levels within the first driving voltage range to be operatively compatible with the high voltage HEMT gate terminal, wherein the transistor device gate terminal is operatively connected to the second driver output via the interface circuit.

19 . The semiconductor switch according to claim 18 , wherein the interface circuit comprises a feedback circuit, the feedback circuit comprising at least one output operatively connected to a driver feedback input; and wherein the feedback circuit is configured to provide a feedback signal to the driver feedback input, the feedback signal corresponding to a sensed current, a sensed voltage, and/or a sensed temperature in the semiconductor switch.

20 . The semiconductor switch according to claim 18 comprising a feedback circuit, the feedback circuit comprising at least one output operatively connected to the interface circuit, wherein the feedback circuit is configured to provide a feedback signal to the interface circuit, the feedback signal corresponding to a sensed current, a sensed voltage, and/or a sensed temperature in the semiconductor switch.

21 . The semiconductor switch according to claim 18 , wherein the interface circuit comprises a Miller clamp transistor, the Miller clamp transistor comprising a plurality of Miller clamp gates, wherein the interface circuit is configured such that an on-state resistance of the Miller clamp transistor depends on which Miller clamp gate(s) of the plurality of Miller clamp gates is active.

22 . The semiconductor switch according to claim 18 , wherein the interface circuit comprises a plurality of Miller clamp transistors having different on-state resistances, optionally wherein the interface circuit further comprises a logic circuit configured to control activation of each Miller clamp transistor of the plurality of Miller clamp transistors.

23 . The semiconductor switch according to claim 15 , wherein the transistor device gate terminal is operatively connected to the second driver output via a second resistor, or via a second resistor in series with a second diode; and wherein the transistor device gate terminal is operatively connected to the fourth driver output via a fourth resistor, wherein a resistance of the fourth resistor is greater than a resistance of the second resistor.

24 . The semiconductor switch according to claim 18 , wherein the interface circuit comprises a third Miller clamp transistor, the third Miller clamp transistor comprising a third Miller clamp drain terminal, wherein the third Miller clamp drain terminal is operatively connected to the high voltage HEMT gate terminal; and wherein the interface circuit further comprises a fourth Miller clamp transistor, the fourth Miller clamp transistor comprising a fourth Miller clamp drain terminal, wherein the fourth Miller clamp drain terminal is operatively connected to the transistor device gate terminal.

25 . A method of operating a semiconductor switch, the semiconductor switch comprising a first main terminal, a second main terminal, and a control terminal, the semiconductor switch comprising:

a high voltage HEMT, the high voltage HEMT comprising a high voltage HEMT source terminal, a high voltage HEMT drain terminal, and a high voltage HEMT gate terminal; and

a high voltage transistor device, the high voltage transistor device comprising a transistor device first terminal, a transistor device second terminal, and a transistor device gate terminal;

wherein the high voltage HEMT source terminal and the transistor device first terminal are operatively connected to the first main terminal; and

wherein the high voltage HEMT drain terminal and the transistor device second terminal are operatively connected to the second main terminal;

wherein the method comprises:

driving the control terminal, by a driver via a first driver output, within a first driving voltage range; and

driving the transistor device gate terminal, by a driver via a second driver output, within a second driving voltage range;

wherein the transistor device gate terminal is operatively connected to a fourth driver output of the driver, and wherein the method further comprises:

when the semiconductor switch is in a turn-off mode, providing to the transistor device gate terminal selectably either:

a regular turn-off signal comprising a second driving voltage level within the second driving voltage range, from the driver via the second driver output; or

a delayed turn-off signal, or a slower turn-off signal, comprising a fourth driving voltage level within the second driving voltage range, from the driver via the fourth driver output.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 20, 2024
From: UDREA, FLORIN; FINDLAY, JOHN WILLIAM
To: CAMBRIDGE GAN DEVICES LIMITED
Reel/Frame 067465/0558 →
Priority Claims (2)
GB 2314270 · Sep 18, 2023 · national
LU 505902 · Dec 22, 2023 · national
Continuity (2)
Continuation In Part 18393946 · Dec 22, 2023
Related Publication 20250096794A1 · Mar 20, 2025
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