Semiconductor device

Abstract

The present disclosure relates to a semiconductor device. An object is to provide a semiconductor device capable of achieving cost saving and space saving. A semiconductor device of the present disclosure includes: a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a second switching element connected in parallel with the first switching element, the second switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element and the second switching element by supplying a control signal based on a potential of a GND terminal to a control terminal of the first switching element and a control terminal of the second switching element; and a resistor connected between the low voltage terminal of the first switching element and the low voltage terminal of the second switching element. The GND terminal of the driving circuit is connected between the low-voltage terminal of the second switching element and the resistor.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor device. Background Art

[0002] A technique is disclosed in Patent Document 1, in which the emitter potential is reduced by providing a negative power supply to the emitter portion of a switching element, so as to increase the gate voltage of the switching element. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-175221 Summary of the Invention Technical Problem to be Solved by the Invention

[0004] However, an additional external power supply is required to maintain the negative power supply, so high cost and large space are needed, which is a problem.

[0005] In order to solve the above problems, an object of the present disclosure is to provide a semiconductor device capable of cost saving and space saving. Technical Means for Solving the Technical Problem

[0006] A preferred embodiment of the present disclosure is a semiconductor device, which includes: a first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; a second switching element connected in parallel with the first switching element and having a high-voltage terminal, a low-voltage terminal, and a control terminal; a drive circuit that provides control signals based on the potential of the GND terminal to the control terminals of the first switching element and the second switching element to drive the first switching element and the second switching element; and a resistor connected between the low-voltage terminal of the first switching element and the low-voltage terminal of the second switching element, and the GND terminal of the drive circuit is connected between the low-voltage terminal of the second switching element and the resistor. Advantageous Effects of the Invention

[0007] According to the embodiment of the present disclosure, the gate voltage of the switching element is changed without providing a negative power supply, so as to achieve cost saving and space saving. Brief Description of the Drawings

[0008] Figure 1 It is a diagram showing the semiconductor device according to Embodiment 1 of the present disclosure. Figure 2 It is a diagram showing the semiconductor device according to Embodiment 2 of the present disclosure. Figure 3 It is a diagram showing the semiconductor device according to Embodiment 3 of the present disclosure. Figure 4 It is a diagram showing the semiconductor device according to Embodiment 4 of the present disclosure. Figure 5 This is a diagram showing the semiconductor device according to Embodiment 5 of the present disclosure. Figure 6 This is a diagram showing the semiconductor device according to Embodiment 6 of the present disclosure. Figure 7 This is a diagram showing the semiconductor device according to Embodiment 7 of the present disclosure. Detailed Embodiments

[0009] Embodiment 1 Figure 1 This is a diagram showing the semiconductor device according to Embodiment 1 of the present disclosure. The semiconductor device 100 includes a first switching element 4. The first switching element 4 is, for example, an IGBT. The first switching element 4 has a high-voltage terminal, a low-voltage terminal, and a control terminal. When the first switching element 4 is an IGBT, the high-voltage terminal is the collector, the low-voltage terminal is the emitter, and the control terminal is the gate. A reflux element 8 is connected between the emitter and the collector of the first switching element.

[0010] In addition, in the present disclosure, the first switching element 4 is shown as an IGBT, but it is not limited thereto. For example, it may also be a MOSFET. When the first switching element 4 is a MOSFET, the high-voltage terminal is the drain, the low-voltage terminal is the source, and the control terminal is the gate. The same applies to the second switching element 6 and the third switching element 18 described later.

[0011] The first switching element 4 is connected in parallel with the second switching element 6. The second switching element 6 is, for example, an IGBT. The second switching element 6 has a high-voltage terminal, a low-voltage terminal, and a control terminal. When the second switching element 6 is an IGBT, the high-voltage terminal is the collector, the low-voltage terminal is the emitter, and the control terminal is the gate.

[0012] Furthermore, the semiconductor device 100 includes a drive circuit 2. The drive circuit 2 is a circuit that drives the first switching element 4 and the second switching element 6. The drive circuit 2 drives the first switching element 4 and the second switching element 6 by supplying a control signal based on the potential of the GND terminal 12 to the gates of the first switching element 4 and the second switching element 6.

[0013] A resistor 10 is connected between the emitters of the first switching element 4 and the second switching element 6. A GND terminal 12 is connected between the second switching element 6 and the resistor 10.

[0014] An operation example of the semiconductor device 100 is shown. When the drive circuit 2 outputs the conduction signal voltage Vo of the first switching element 4 and the second switching element 6, the first switching element 4 and the second switching element 6 become conductive states. Since a current then flows through the resistor 10, a potential difference is generated across the resistor 10.

[0015] At this time, the emitter potential of the first switching element 4 becomes lower than the potential of the GND terminal 12. Therefore, if the gate voltage of the first switching element 4 is set to Vge, then Vo < Vge holds.

[0016] In a general switching element, the higher the gate voltage, the smaller the resistance component between the collector and the emitter becomes, and thus the consumed loss is reduced. According to the present embodiment, Vge can be made higher with respect to Vo, and therefore, the resistance component between the collector and the emitter of the first switching element 4 can be reduced, and the consumed loss can be reduced.

[0017] In addition, in a general switching element, when the current flowing between the collector and the emitter reaches a specific current value, it saturates and no current can flow. The higher the gate voltage, the larger the specific current value becomes. According to the present embodiment, Vge can be made higher with respect to Vo, and therefore, the current that can flow between the collector and the emitter can be increased.

[0018] As described above, according to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved.

[0019] Embodiment 2 Figure 2 FIG. is a diagram showing a semiconductor device according to Embodiment 2 of the present disclosure. The semiconductor device 200 is different from the semiconductor device 100 in that the second switching element 6a is built in the first switching element 4a.

[0020] According to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, by building the second switching element in the first switching element, further space savings can be achieved.

[0021] Embodiment 3 Figure 3 FIG. is a diagram showing a semiconductor device according to Embodiment 3 of the present disclosure. The semiconductor device 300 is different from the semiconductor device 200 in that a coil 13 is connected in place of the resistor 10.

[0022] An operation example when the semiconductor device 300 is turned on is shown. When the drive circuit 2 outputs the conduction signal voltage Vo of the first switching element 4a and the second switching element 6a, the first switching element 4a and the second switching element 6a become conductive states. Then, a current flows through the coil 13, and an electromotive force v (v = L·di / dt) is generated.

[0023] At this time, the emitter potential of the first switching element 4a becomes lower than the potential of the GND terminal 12. Therefore, for the gate voltage Vge of the first switching element 4a, Vo < Vge holds. Thus, the conduction loss generated in the first switching element 4a can be reduced.

[0024] On the other hand, when the semiconductor device 300 is turned off, no current flows through the coil 13, and a back electromotive force -v (-v = L · -di / dt) is generated. At this time, the conduction signal voltage Vo of the first switching element is 0V. Therefore, for the gate voltage Vge of the first switching element 4a, Vo > Vge holds. Thus, the turn-off loss generated in the first switching element 4a can be reduced.

[0025] As described above, according to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, by using a coil instead of a resistor, further cost savings can be achieved.

[0026] In addition, the way of connecting the coil 13 is shown here, but as long as it is an element that generates an electromotive force when current flows, for example, it can be a way of connecting a wiring.

[0027] Embodiment 4 Figure 4 FIG. is a diagram showing a semiconductor device according to Embodiment 4 of the present disclosure. The semiconductor device 400 is different from the semiconductor device 100 in that it includes a drive circuit 2a having a current source 14 instead of the drive circuit 2 and the second switching element 6. In this case, the resistor 10 is connected between the emitter of the first switching element 4 and the GND terminal 12a of the drive circuit 2a.

[0028] An operation example of the semiconductor device 400 is shown. If the drive circuit 2a outputs the conduction signal voltage Vo of the first switching element 4, the first switching element 4 becomes in a conduction state. At the same time, the drive circuit 2a uses the current source 14 to make current flow in the direction from the GND terminal 12a toward the emitter of the first switching element 4. When current flows, a potential difference is generated across the resistor 10.

[0029] At this time, the emitter potential of the first switching element 4 becomes lower than the potential of the GND terminal 12a. Therefore, for the gate voltage Vge of the first switching element 4, Vo < Vge holds. Thus, the loss generated in the first switching element 4 can be reduced.

[0030] In addition, the current source 14 can change the magnitude of the current flowing through the resistor 10. Thus, the semiconductor device 400 can adjust the decrease amplitude of the emitter potential of the first switching element 4, that is, the increase amplitude of the gate-emitter voltage of the first switching element.

[0031] In addition, the current source 14 can change the magnitude of the current flowing through the resistor 10 regardless of the magnitude of the current flowing through the first switching element 4. That is, in the semiconductor device 400, even when the current flowing through the first switching element 4 is low, the gate-emitter voltage of the first switching element 4 can be increased.

[0032] As described above, according to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, the above effects can be obtained regardless of the magnitude of the current flowing through the first switching element 4.

[0033] Embodiment 5 Figure 5 FIG. is a diagram showing a semiconductor device according to Embodiment 5 of the present disclosure. The semiconductor device 500 is different from the semiconductor device 400 in that it includes a drive circuit 2b that causes current to flow in a direction opposite to that of the drive circuit 2a instead of the drive circuit 2a.

[0034] An operation example of the semiconductor device 500 is shown. When the drive circuit 2b outputs the conduction signal voltage Vo of the first switching element 4, the first switching element 4 becomes conductive. At the same time, the drive circuit 2b uses the current source 14 to cause current to flow in the direction from the GND terminal 12a toward the emitter of the first switching element 4. When current flows, a potential difference is generated across the resistor 10.

[0035] At this time, the emitter potential of the first switching element 4 becomes higher than the potential of the GND terminal 12a. Therefore, for the gate voltage Vge of the first switching element 4, Vo > Vge holds. As a result, the current that can flow through the first switching element 4 is suppressed, and thus damage to the first switching element 4 can be suppressed.

[0036] As described above, according to the present embodiment, by reducing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, damage to the switching element can also be suppressed.

[0037] Embodiment 6 Figure 6 FIG. is a diagram showing a semiconductor device according to Embodiment 6 of the present disclosure. The semiconductor device 600 is different from the semiconductor device 200 in that it includes a diode 16 connected in parallel with the resistor 10.

[0038] The diode 16 is a diode whose anode is connected to the emitter of the first switching element 4a. Thus, in the present embodiment, the paths for turning on the gate of the first switching element 4a are two paths: a path via the resistor 10 and a path via the diode 16. That is, the resistance component in each path can be reduced, and thus the switching-on speed of the first switching element 4a can be increased.

[0039] As described above, according to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, the switching-on speed can also be increased.

[0040] Embodiment 7 Figure 7 FIG. is a diagram showing a semiconductor device according to Embodiment 7 of the present disclosure. The semiconductor device 700 is different from the semiconductor device 200 in that it includes a third switching element 18. The third switching element 18 is a switching element connected in parallel with the resistor 10 and having its emitter connected to the emitter of the first switching element 4a.

[0041] In the semiconductor device 700, when turning off the first switching element 4a and the built-in second switching element 6a, the third switching element 18 is turned on. Thus, in the present embodiment, the paths for turning off the gate of the first switching element 4a are two paths: a path via the resistor 10 and a path via the third switching element 18. That is, the resistance component in each path can be reduced, and thus the switching-off speed of the first switching element 4a can be increased.

[0042] As described above, according to the present embodiment, by increasing the gate voltage of the switching element without providing a negative power supply, cost savings and space savings can be achieved. In addition, according to the present embodiment, the switching-off speed can also be increased.

[0043] Embodiment 8 In the semiconductor devices 100 to 700, the case where the switching element is formed of silicon is shown. The semiconductor device of the present embodiment is different from the semiconductor devices 100 to 700 in that the switching element is formed of a wide-bandgap semiconductor. The wide-bandgap semiconductor is, for example, a gallium nitride-based material, a gallium oxide-based material, or diamond.

[0044] The wide-bandgap semiconductor has higher heat resistance than silicon. Therefore, by forming the switching element from a wide-bandgap semiconductor, the semiconductor device can operate under higher temperature conditions, or the heat dissipation structure of the entire semiconductor device can be simplified.

[0045] In addition, the wide-bandgap semiconductor has lower power loss than silicon. Therefore, by forming the switching element from a wide-bandgap semiconductor, the semiconductor device can operate at a higher speed.

[0046] Moreover, the wide bandgap semiconductor has higher breakdown voltage and allowable current density than silicon. Therefore, by forming the switching element from the wide bandgap semiconductor, the switching element can be further miniaturized, and space saving of the semiconductor device can be further achieved.

[0047] In addition, in the present embodiment, it is preferable that all the switching elements included in the semiconductor device are formed from the wide bandgap semiconductor, but at least one switching element may be formed from the wide bandgap semiconductor. In this case, the effects described in the present embodiment can also be obtained.

[0048] Hereinafter, all aspects of the present disclosure are summarized and described as appendices.

[0049] (Appendix 1) A semiconductor device, comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A second switching element connected in parallel with the first switching element and having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies control signals referenced to the potential of the GND terminal to the control terminal of the first switching element and the control terminal of the second switching element to drive the first switching element and the second switching element; and A resistor connected between the low-voltage terminal of the first switching element and the low-voltage terminal of the second switching element, wherein the GND terminal of the drive circuit is connected between the low-voltage terminal of the second switching element and the resistor. (Appendix 2) The semiconductor device according to Appendix 1, further comprising a diode connected in parallel with the resistor and having an anode connected to the low-voltage terminal of the first switching element. (Appendix 3) The semiconductor device according to Appendix 1 or 2, further comprising a third switching element connected in parallel with the resistor, wherein when the first switching element and the second switching element are turned off, the drive circuit turns on the third switching element. (Appendix 4) The semiconductor device according to any one of Appendices 1 to 3, wherein the second switching element is built in the first switching element. (Appendix 5) The semiconductor device according to any one of Appendices 1 to 4, wherein the resistor is a coil or a wiring. (Appendix 6) A semiconductor device, comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies a control signal referenced to the potential of the GND terminal to the control terminal of the first switching element to drive the first switching element; and A resistor connected between the low-voltage terminal of the first switching element and the GND terminal of the drive circuit, The drive circuit has a current source that causes current to flow through the resistor in a direction from the GND terminal toward the low-voltage terminal. (Supplementary Note 7) A semiconductor device comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies a control signal referenced to the potential of the GND terminal to the control terminal of the first switching element to drive the first switching element; and A resistor disposed between the low-voltage terminal of the first switching element and the GND terminal of the drive circuit, The drive circuit has a current source that causes current to flow through the resistor in a direction from the low-voltage terminal toward the GND terminal. (Supplementary Note 8) The semiconductor device according to any one of Supplementary Notes 1 to 7, The first switching element is formed of a wide bandgap semiconductor. Reference Numeral Explanation

[0050] 2 Drive circuit 2a Drive circuit 2b Drive circuit 4 First switching element 4a First switching element 6 Second switching element 6a Second switching element 10 Resistor 13 Coil 14 Current source 16 Diode 18 Third switching element 100 Semiconductor device 200 Semiconductor device 300 Semiconductor device 400 Semiconductor device 500 Semiconductor device 600 Semiconductor device 700 Semiconductor device.

Claims

1. A semiconductor device, characterized in that, Comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A second switching element connected in parallel with the first switching element, having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies control signals referenced to the potential of the GND terminal to the control terminal of the first switching element and the control terminal of the second switching element to drive the first switching element and the second switching element; And A resistor connected between the low-voltage terminal of the first switching element and the low-voltage terminal of the second switching element, The GND terminal of the drive circuit is connected between the low-voltage terminal of the second switching element and the resistor.

2. The semiconductor device according to claim 1, characterized in that It further includes a diode connected in parallel with the resistor, and the anode is connected to the low-voltage terminal of the first switching element.

3. The semiconductor device according to claim 1, characterized in that It further includes a third switching element connected in parallel with the resistor, When the first switching element and the second switching element are turned off, the drive circuit turns on the third switching element.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that The second switching element is built in the first switching element.

5. The semiconductor device according to any one of claims 1 to 3, characterized in that The resistor is a coil or a wiring.

6. A semiconductor device, characterized in that, Comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies a control signal referenced to the potential of the GND terminal to the control terminal of the first switching element to drive the first switching element; And A resistor connected between the low-voltage terminal of the first switching element and the GND terminal of the drive circuit, The drive circuit has a current source that causes current to flow through the resistor in a direction from the GND terminal toward the low-voltage terminal.

7. A semiconductor device, characterized in that, Comprising: A first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; A drive circuit that supplies a control signal referenced to the potential of the GND terminal to the control terminal of the first switching element to drive the first switching element; And A resistor disposed between the low-voltage terminal of the first switching element and the GND terminal of the drive circuit, The drive circuit has a current source that causes current to flow through the resistor in a direction from the low-voltage terminal toward the GND terminal.

8. The semiconductor device according to any one of claims 1 to 3, 6, 7, characterized in that The first switching element is formed of a wide-bandgap semiconductor.

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