Semiconductor Devices

Abstract

The present invention addresses a scheme for a plurality of protection circuits without changing the layout of a switching element. A semiconductor device according to the present invention comprises: a main switching element that is formed from a MOSFET, and a sense switching element that has an area smaller than that of the main switching element in plan view and is for detecting current flowing through the main switching element. A first gate terminal that is a gate terminal of the sense switching element is disposed between a second gate terminal that is a gate terminal of the main switching element and a source terminal of the sense switching element.

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a switching element that includes a main switching element and a sense switching element. [Background technology]

[0002] Conventionally, a current sensing type short circuit current detection circuit has been used to realize short circuit protection. For example, Patent Document 1 discloses a semiconductor device including a main semiconductor element section for passing a main current, a sense semiconductor element section for passing a sense current for detecting the main current, a sense resistor, a comparator, and a control circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-171478 Summary of the Invention [Problem to be solved by the invention]

[0004] The current sensing method described above is configured with a switching element that integrates a main switching element and a sense switching element.

[0005] Incidentally, as a method for realizing short-circuit protection, in addition to the current sense type short-circuit current detection circuit (hereinafter referred to as current sense circuit) disclosed in Patent Document 1, there is also a DESAT type short-circuit current detection circuit (hereinafter referred to as DESAT circuit).

[0006] The DESAT circuit is a protection circuit that includes a high-voltage diode external to the main switching element, a resistor, a capacitor, and a control circuit including a constant current source.

[0007] If no short circuit occurs, the main switching element turns on and the drain voltage of the main switching element drops to the on-voltage, causing the current supplied from the constant current source to flow into the drain terminal of the main switching element via the resistor and high-voltage diode.

[0008] When a short circuit occurs, the drain voltage of the main switching element becomes higher than the on-voltage, and the constant current flowing into the drain terminal of the main switching element is supplied to the capacitor in the DESAT circuit. When the voltage of the capacitor exceeds a predetermined threshold, a short circuit is detected and a protective operation is performed.

[0009] In a DESAT circuit, there is no need to integrate sense switching elements, as in the semiconductor device exemplified in Patent Document 1. Therefore, it is necessary to create different layouts for the switching elements, integrating sense switching elements for switching elements that are protected by a current sense circuit, and not integrating sense switching elements for switching elements that are protected by a DESAT circuit.

[0010] The technology disclosed in this specification has been made in consideration of the problems described above, and is a technology that can accommodate multiple protection circuit types without changing the layout of the switching elements. [Means for solving the problem]

[0011] A semiconductor device according to a first aspect of the technology disclosed in the present specification is a semiconductor device including a main switching element configured as a MOSFET, and a sense switching element configured as a MOSFET, having a smaller area in a plan view than the main switching element, and configured to detect a current flowing through the main switching element, wherein a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element. The sense switching element further includes a resistor connected to the source terminal of the sense switching element, a capacitor connected to the resistor, and a control circuit, wherein when the first gate terminal and the source terminal are short-circuited and the voltage of the capacitor exceeds a predetermined threshold, the control circuit controls the voltage applied to the second gate terminal. do. [Effects of the Invention]

[0012] According to at least the first aspect of the technology disclosed in the present specification, it is possible to accommodate a plurality of protection circuit types without changing the layout of the switching elements, thereby improving convenience.

[0013] Furthermore, objects, features, aspects, and advantages associated with the technology disclosed herein will become more apparent from the detailed description and accompanying drawings set forth below. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram schematically illustrating an example of a configuration of a semiconductor device according to an embodiment; [Figure 2] FIG. 10 is a diagram schematically illustrating another example of the configuration of the semiconductor device according to the embodiment. [Figure 3] 1 is a diagram schematically illustrating an example of the arrangement of the gate terminal of a sense switching element, the gate terminal of a main switching element, and the source terminal of a sense switching element, in particular, of the configuration of a semiconductor device according to the present embodiment. [Figure 4] 1 is a diagram schematically illustrating an example of the arrangement of the gate terminal of a sense switching element, the gate terminal of a main switching element, and the source terminal of a sense switching element, in particular, of the configuration of a semiconductor device according to the present embodiment. [Figure 5] 1 is a diagram schematically illustrating an example of a configuration of a semiconductor device according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the accompanying drawings. In the following embodiments, detailed features will be shown for the purpose of explaining the technology, but these are merely examples and are not necessarily essential features for enabling the embodiments to be implemented.

[0016] The drawings are schematic, and for the sake of convenience, components may be omitted or simplified as appropriate. The relative sizes and positions of components shown in different drawings are not necessarily accurately depicted and may be changed as appropriate. Hatching may also be used in drawings such as plan views that are not cross-sectional views to facilitate understanding of the embodiments.

[0017] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0018] Furthermore, in the description given in this specification, when a certain component is described as "comprising," "including," or "having," unless otherwise specified, this is not an exclusive expression that excludes the presence of other components.

[0019] Furthermore, although ordinal numbers such as "first" or "second" may be used in the descriptions in this specification, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and the contents of the embodiments are not limited to the order that may result from these ordinal numbers.

[0020] First Embodiment The semiconductor device according to this embodiment will be described below.

[0021] <Configuration of semiconductor device> FIG. 1 is a diagram schematically showing an example of the configuration of a semiconductor device according to this embodiment.

[0022] As shown in FIG. 1, the semiconductor device includes a switching element 3 and a DESAT circuit 9, which is a protection circuit.

[0023] The switching element 3 integrates into a single element a main switching element 1 configured as a metal-oxide-semiconductor field-effect transistor (MOSFET) or the like, and a sense switching element 2 configured as a MOSFET that has a smaller area in a plan view than the main switching element 1 and senses the current flowing through the main switching element 1.

[0024] In switching element 3, gate terminal 4 of main switching element 1 and gate terminal 6 of sense switching element 2 are not connected and are integrated independently of each other. Furthermore, drain terminal 21 of main switching element 1 and drain terminal 21 of sense switching element 2 are common. Furthermore, sense switching element 2 has a built-in diode 8.

[0025] The DESAT circuit 9 includes a resistor 22 connected to the source terminal 7 of the sense switching element 2, a capacitor 23 connected to the resistor 22, and a control circuit 24 including a constant current source. The control circuit 24 controls the voltage applied to the gate terminal 4 of the main switching element 1 while supplying a constant current to a connection point 25 where the resistor 22 and the capacitor 23 are connected.

[0026] In the DESAT circuit 9, when a short-circuit current flows between the drain terminal 21 and source terminal 5 of the main switching element 1, the drain voltage of the main switching element 1 becomes higher than the on-voltage, and the constant current that had been flowing into the drain terminal 21 of the main switching element 1 is supplied to a capacitor 23 in the DESAT circuit 9. When the voltage of the capacitor 23 exceeds a predetermined threshold value, a control circuit 24 detects the short-circuit operation and performs a protective operation (controlling the voltage applied to the gate terminal 4 of the main switching element 1).

[0027] Here, DESAT circuit 9 does not include a high-voltage diode. DESAT circuit 9 also shorts gate terminal 6 of sense switching element 2 and source terminal 7 of sense switching element 2 together.

[0028] By shorting the gate terminal 6 of the sense switching element 2 and the source terminal 7 of the sense switching element 2, the diode 8 built into the sense switching element 2 can be used as a high-voltage diode. This makes it possible to build in a high-voltage diode that is normally required in a DESAT circuit, leading to cost reduction and space savings.

[0029] FIG. 2 is a diagram schematically showing another example of the configuration of the semiconductor device according to the present embodiment.

[0030] As shown in FIG. 2, the semiconductor device includes a switching element 3 and a current sensing circuit 10 that is a protection circuit.

[0031] The current sense circuit 10 includes a sense resistor 32 connected to the source terminal 7 of the sense switching element 2, a comparator 33 that compares the voltage input to the sense resistor 32 with a trip voltage (reference voltage), a voltage source 35 that inputs the trip voltage to the comparator 33, and a control circuit 34 connected to the comparator 33. The control circuit 34 controls the voltage applied to the gate terminal 4 of the main switching element 1 based on the output from the comparator 33.

[0032] When a short-circuit current flows between the drain terminal 21 and source terminal 5 of the main switching element 1, the current sense circuit 10 detects, from the output of the comparator 33, that the voltage applied to the source terminal 7 of the sense switching element 2 exceeds a trip voltage (a reference voltage for determining whether to cut off the current) provided by the voltage source 35. When this happens, the control circuit 34 performs a protective operation (controlling the voltage applied to the gate terminal 4 of the main switching element 1).

[0033] Here, the current sense circuit 10 shorts the gate terminal 6 of the sense switching element 2 and the gate terminal 4 of the main switching element 1 together.

[0034] By shorting the gate terminal 4 of the main switching element 1 and the gate terminal 6 of the sense switching element 2, the diode 8 built into the sense switching element 2 can be used as a high-voltage diode. This makes it possible to build in a high-voltage diode, leading to cost reduction and space savings.

[0035] The gate terminal 6 of the sense switching element 2 is disposed between the gate terminal 4 of the main switching element 1 and the source terminal 7 of the sense switching element 2. By arranging the gate terminal 6 of the sense switching element 2 between the gate terminal 4 of the main switching element 1 and the source terminal 7 of the sense switching element 2 and integrating them as the switching element 3, it is possible to easily achieve a short circuit between the gate terminal 6 and the source terminal 7 or between the gate terminal 6 and the gate terminal 4 over the shortest distance.

[0036] 3 and 4 are diagrams that schematically show examples of the arrangement of the gate terminal 6 of the sense switching element 2, the gate terminal 4 of the main switching element 1, and the source terminal 7 of the sense switching element 2, in particular, of the configuration of the semiconductor device according to this embodiment.

[0037] As shown in the example in Figure 3, if the gate terminal 6 of the sense switching element 2 is located between the gate terminal 4 of the main switching element 1 and the source terminal 7 of the sense switching element 2, when the DESAT circuit 9 is connected, the gate terminal 6 of the sense switching element 2 and the source terminal 7 of the sense switching element 2 can be connected over the shortest distance to create a short circuit.

[0038] Furthermore, as shown in the example in Figure 4, if the gate terminal 6 of the sense switching element 2 is arranged between the gate terminal 4 of the main switching element 1 and the source terminal 7 of the sense switching element 2, when connecting the current sense circuit 10, the gate terminal 6 of the sense switching element 2 and the gate terminal 4 of the main switching element 1 can be connected over the shortest distance to create a short circuit.

[0039] According to the above configuration, it is possible to selectively connect the DESAT circuit 9 or the current sense circuit 10 without changing the layout of the switching element 3. In other words, the layout of the switching element 3 can be shared whether the DESAT circuit 9 is connected or the current sense circuit 10 is connected.

[0040] <Second embodiment> A semiconductor device according to the present embodiment will be described. In the following description, components similar to those described in the above embodiments will be denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0041] <Configuration of semiconductor device> FIG. 5 is a diagram schematically illustrating an example of the configuration of a semiconductor device according to this embodiment.

[0042] As shown in FIG. 5, the semiconductor device includes a plurality of switching elements 3 connected in parallel with each other, and a protection circuit 12.

[0043] The switching element 3 integrates a main switching element 1 and a sense switching element 2 into a single element. A plurality of switching elements 3 are connected in parallel to form a power module 11. In each switching element 3, the gate terminal 6 of the sense switching element 2 is disposed between the gate terminal 4 of the main switching element 1 and the source terminal 7 of the sense switching element 2.

[0044] The protection circuit 12 includes a resistor 22 connected to the source terminal 7 of the sense switching element 2 in any one of the switching elements 3, a capacitor 23 connected to the resistor 22, a sense resistor 32 connected to the source terminal 7 of the sense switching element 2 in any one of the switching elements 3, a comparator 33 that compares the voltage input to the sense resistor 32 with a trip voltage (reference voltage), a voltage source 35 that inputs the trip voltage to the comparator 33, and a driver IC 42 that includes a constant current source.

[0045] A DESAT circuit can be configured with the resistor 22, the capacitor 23, and the driver IC 42. A current sensing circuit can be configured with the sense resistor 32, the comparator 33, the voltage source 35, and the driver IC 42.

[0046] Here, the sense switching element 2 to which resistor 22 is connected and the sense switching element 2 to which sense resistor 32 is connected are assumed to be sense switching elements 2 in different switching elements 3. In addition, in the switching element 3 to which resistor 22 is connected, the gate terminal 6 and the source terminal 7 are short-circuited, and in the switching element 3 to which sense resistor 32 is connected, the gate terminal 4 and the gate terminal 6 are short-circuited.

[0047] The driver IC 42 controls the voltage applied to the gate terminal 4 of the main switching element 1 of any of the switching elements 3 while supplying a constant current to the connection point 25 where the resistor 22 and the capacitor 23 are connected. Specifically, the driver IC 42 controls the voltage applied to the gate terminal 4 of the main switching element 1 when the voltage of the capacitor 23 exceeds a predetermined threshold value. In FIG. 5, the driver IC 42 controls the voltage applied to the gate terminal 4 of the switching element 3 to which the sense resistor 32 is connected, but because the gate terminals 4 of multiple switching elements 3 connected in parallel are connected to each other, this is the same as controlling the voltage applied to the gate terminal 4 of the other switching elements 3 connected in parallel.

[0048] Furthermore, the driver IC 42 controls the voltage applied to the gate terminal 4 of the main switching element 1 in any one of the switching elements 3 based on the output from the comparator 33 .

[0049] In the above case, the driver IC 42 is shared between configuring the DESAT circuit and configuring the current sense circuit, but the driver ICs 42 configuring the DESAT circuit and the current sense circuit may be provided separately.

[0050] Resistor 22, capacitor 23, and driver IC 42 that constitute a DESAT circuit are connected to one of multiple switching elements 3 connected in parallel, and sense resistor 32, comparator 33, voltage source 35, and driver IC 42 that constitute a current sense circuit are connected to another switching element 3. By doing so, even if a short-circuit current flows between drain terminal 21 and source terminal 5 of main switching element 1 in multiple switching elements 3 among the multiple switching elements 3 connected in parallel, the short-circuit current can be detected by the DESAT circuit or current sense circuit connected to source terminal 7 of each main switching element 1, thereby appropriately protecting the corresponding main switching element 1. In other words, by increasing the number of times a DESAT circuit or current sense circuit is connected to a switching element 3, each of the multiple switching elements 3 connected in parallel can be effectively protected.

[0051] <Third embodiment> A semiconductor device according to the present embodiment will be described. In the following description, components similar to those described in the above embodiments will be denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0052] <Configuration of semiconductor device> In this embodiment, at least one of the sense switching elements 2 integrated in the switching element 3 is a SiC-MOSFET.

[0053] In the DESAT circuit of the configuration shown in FIG. 5, if the threshold voltage for determining whether a short-circuit current has been detected is Vdesat, the current supplied from the constant current source in the driver IC 42 is Ichg, the external resistance is Rdesat, the capacitance of the external capacitor is Cdesat, the forward voltage of the high-voltage diode is Vf, and the delay time (response speed) from the occurrence of a short circuit is Tdesat, Tdesat can be expressed as follows:

[0054] Tdesat={Cdesat×[Vdesat-(Vf+Ichg×Rdesat)]} / Ichg According to the above formula, as Vf increases, Tdesat decreases.

[0055] In the switching element 3 having the sense switching element 2 made of SiC-MOSFET, the forward voltage Vf of the built-in diode at low current is higher than that of Si (0.6 V). Therefore, if the sense switching element 2 is a SiC-MOSFET, the response speed can be increased.

[0056] <Effects of the above-described embodiments> Next, examples of effects obtained by the above-described embodiments will be described. Note that in the following description, the effects will be described based on the specific configurations exemplified in the above-described embodiments, but these may be replaced with other specific configurations exemplified in the present specification as long as the same effects are obtained. In other words, for convenience, only one of the corresponding specific configurations may be described as a representative below, but the representatively described specific configuration may be replaced with another corresponding specific configuration.

[0057] Furthermore, the replacement may be made across multiple embodiments, i.e., configurations illustrated in different embodiments may be combined to produce the same effect.

[0058] According to the embodiment described above, the semiconductor device includes a main switching element 1 configured as a MOSFET, and a sense switching element 2. The sense switching element 2 is configured as a MOSFET. The sense switching element 2 has a smaller area in a plan view than the main switching element 1. The sense switching element 2 detects the current flowing through the main switching element 1. A first gate terminal, which is the gate terminal of the sense switching element 2, is disposed between a second gate terminal, which is the gate terminal of the main switching element 1, and a source terminal 7 of the sense switching element 2. Here, the first gate terminal corresponds to, for example, gate terminal 6. The second gate terminal corresponds to, for example, gate terminal 4.

[0059] This configuration makes it possible to accommodate a variety of protection circuit types without changing the layout of the switching element 3. This improves convenience. Furthermore, by arranging the gate terminal 6 between the gate terminal 4 and the source terminal 7, when shorting the gate terminal 6 and the gate terminal 4, and when shorting the gate terminal 6 and the source terminal 7, they can be easily connected over the shortest distance.

[0060] Furthermore, even if other configurations shown as examples in this specification are appropriately added to the above configuration, that is, even if other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be achieved.

[0061] Furthermore, according to the embodiment described above, the semiconductor device includes a resistor 22 connected to the source terminal 7 of the sense switching element 2, a capacitor 23 connected to the resistor 22, and a control circuit 24. The gate terminal 6 and the source terminal 7 are short-circuited. When the voltage of the capacitor 23 exceeds a predetermined threshold, the control circuit 24 controls the voltage applied to the gate terminal 4. With this configuration, even if the protection circuit is a DESAT circuit, it can be used without changing the layout of the switching element 3. Furthermore, by short-circuiting the gate terminal 6 and the source terminal 7, the diode 8 built into the sense switching element 2 can be used in place of the high-voltage diode that would normally be separately required outside the switching element 3 in the DESAT system. This allows for cost reduction and space savings.

[0062] Furthermore, according to the embodiment described above, the semiconductor device includes a sense resistor 32 connected to the source terminal 7 of the sense switching element 2, a comparator 33 that compares a voltage input to the sense resistor 32 with a reference voltage and outputs the comparison result, a voltage source 35 that inputs the reference voltage to the comparator 33, and a control circuit 34 connected to the comparator 33. Here, the gate terminal 6 and the gate terminal 4 are short-circuited. The control circuit 34 then controls the voltage applied to the gate terminal 4 based on the output from the comparator 33. With this configuration, even if the protection circuit is a current sense circuit, it can be shared without changing the layout of the switching element 3.

[0063] Furthermore, according to the embodiment described above, a plurality of switching elements 3 are connected in parallel. In each switching element 3, the gate terminal 6, which is the gate terminal of the sense switching element 2, is disposed between the gate terminal 4, which is the gate terminal of the main switching element 1, and the source terminal 7 of the sense switching element 2. This configuration makes it possible to accommodate a plurality of protection circuit types without changing the layout of the switching element 3, thereby improving convenience. Furthermore, by disposing the gate terminal 6 between the gate terminal 4 and the source terminal 7, when shorting the gate terminal 6 and the gate terminal 4, and when shorting the gate terminal 6 and the source terminal 7, the connections can be easily made over the shortest distance.

[0064] Furthermore, according to the embodiment described above, the semiconductor device uses one of the multiple switching elements 3 as a first switching element, and includes a resistor 22 connected to the source terminal 7 of the sense switching element 2 included in the first switching element, a capacitor 23 connected to the resistor 22, and a driver IC 42. Here, the gate terminal 6 of the sense switching element 2 and the source terminal 7 of the sense switching element 2 in the first switching element are short-circuited. When the voltage of the capacitor 23 exceeds a predetermined threshold, the driver IC 42 controls the voltage applied to the gate terminal 4 of the switching element 3. With this configuration, even if a short-circuit current flows between the drain terminal 21 and the source terminal 5 of the main switching element 1 in multiple switching elements 3 out of the multiple switching elements 3 connected in parallel, the short-circuit current can be detected by the DESAT circuit connected to the source terminal 7 of each main switching element 1, thereby appropriately protecting the corresponding main switching element 1.

[0065] Furthermore, according to the embodiment described above, the semiconductor device uses one of the multiple switching elements 3, which is different from the first switching element, as a second switching element, and includes: a sense resistor 32 connected to the source terminal 7 of the sense switching element 2 included in the second switching element; a comparator 33 that compares a voltage input to the sense resistor 32 with a reference voltage and outputs the comparison result; a voltage source 35 that inputs the reference voltage to the comparator 33; and a driver IC 42 connected to the comparator 33. Here, the gate terminal 6 of the sense switching element 2 and the gate terminal 4 of the main switching element 1 in the second switching element are short-circuited. The driver IC 42 controls the voltage applied to the gate terminal 4 of the switching element 3 based on the output from the comparator 33. With this configuration, even if a short-circuit current flows between the drain terminal 21 and the source terminal 5 of the main switching element 1 in multiple switching elements 3 among the multiple switching elements 3 connected in parallel, the short-circuit current can be detected by the current sense circuit connected to the source terminal 7 of each main switching element 1, thereby appropriately protecting the corresponding main switching element 1.

[0066] Furthermore, according to the embodiment described above, the semiconductor device includes one of the multiple switching elements 3 as a first switching element, and another switching element 3 different from the first switching element as a second switching element. The semiconductor device includes: a resistor 22 connected to the source terminal 7 of the sense switching element 2 included in the first switching element; a capacitor 23 connected to the resistor 22; a sense resistor 32 connected to the source terminal 7 of the sense switching element 2 included in the second switching element; a comparator 33 that compares a voltage input to the sense resistor 32 with a reference voltage and outputs the comparison result; a voltage source 35 that inputs the reference voltage to the comparator 33; and a driver IC 42. In the first switching element, the gate terminal 6 of the sense switching element 2 is short-circuited to the source terminal 7 of the sense switching element 2. In the second switching element, the gate terminal 6 of the sense switching element 2 is short-circuited to the gate terminal 4 of the main switching element 1. The driver IC 42 controls the voltage applied to the gate terminal 4 of the switching element 3 when the voltage of the capacitor 23 exceeds a predetermined threshold. Furthermore, the driver IC 42 controls the voltage applied to the gate terminal 4 of the switching element 3 based on the output from the comparator 33. With this configuration, the driver IC 42 can be shared both when configuring the DESAT circuit and when configuring the current sense circuit, thereby achieving cost reduction and space saving.

[0067] Furthermore, according to the embodiment described above, the sense switching element 2 is configured with a SiC-MOSFET. With this configuration, the switching element 3 including the sense switching element 2 of a SiC-MOSFET has a built-in diode with a higher forward voltage Vf at low current than Si (0.6 V). Therefore, compared to the DESAT method in which a high-voltage diode is connected externally, the response speed can be increased by using a built-in SiC-MOSFET diode with a higher forward voltage than Si.

[0068] <Modifications of the above-described embodiments> In the embodiments described above, the material, composition, dimensions, shape, relative positional relationship, or implementation conditions of each component may also be described, but these are merely examples in all aspects and are not limiting.

[0069] Therefore, countless modifications and equivalents not shown as examples are contemplated within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component in at least one embodiment and combining it with a component in another embodiment.

[0070] Furthermore, in the embodiments described above, when a material name is mentioned without any particular specification, it is assumed that the material may contain other additives, such as an alloy, unless a contradiction arises.

[0071] Furthermore, unless a contradiction arises, when it is stated in the above-described embodiments that "one" component is provided, it is also understood that "one or more" of that component may be provided.

[0072] Furthermore, the descriptions in this specification are incorporated by reference for all purposes related to the present technology, and none of them are admitted to be prior art. [Explanation of symbols]

[0073] 1 main switching element, 2 sense switching element, 3 switching element, 4 gate terminal, 5 source terminal, 6 gate terminal, 7 source terminal, 22 resistor, 23 capacitor, 24 control circuit, 32 sense resistor, 33 comparator, 34 control circuit, 35 voltage source, 42 driver IC.

Claims

1. A semiconductor device comprising: a main switching element formed of a MOSFET; and a sense switching element formed of a MOSFET, having a smaller area in a plan view than the main switching element, for detecting a current flowing through the main switching element, a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element; a resistor connected to the source terminal of the sense switching element; a capacitor connected to the resistor; a control circuit, the first gate terminal and the source terminal are shorted together; the control circuit controls the voltage applied to the second gate terminal when the voltage of the capacitor exceeds a predetermined threshold. Semiconductor device.

2. A semiconductor device comprising: a main switching element formed of a MOSFET; and a sense switching element formed of a MOSFET, having a smaller area in a plan view than the main switching element, for detecting a current flowing through the main switching element, a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element; a sense resistor connected to the source terminal of the sense switching element; a comparator that compares a voltage input to the sense resistor with a reference voltage and outputs a comparison result; a voltage source for inputting the reference voltage to the comparator; a control circuit connected to the comparator; the first gate terminal and the second gate terminal are short-circuited, the control circuit controls the voltage applied to the second gate terminal based on the output from the comparator. Semiconductor device.

3. A semiconductor device in which a plurality of switching elements are connected in parallel, the switching elements including a main switching element formed of a MOSFET and a sense switching element formed of a MOSFET and having a smaller area in a plan view than the main switching element and for detecting a current flowing through the main switching element, In each of the switching elements, a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element; one of the plurality of switching elements is a first switching element; a resistor connected to the source terminal of the sense switching element included in the first switching element; a capacitor connected to the resistor; a driver IC; the first gate terminal of the sense switching element and the source terminal of the sense switching element are short-circuited, When the voltage of the capacitor exceeds a predetermined threshold value, the driver IC controls the voltage applied to the second gate terminal of the switching element. Semiconductor device.

4. A semiconductor device in which a plurality of switching elements are connected in parallel, the switching elements including a main switching element formed of a MOSFET and a sense switching element formed of a MOSFET, the sense switching element having a smaller area in a plan view than the main switching element, and for detecting a current flowing through the main switching element, In each of the switching elements, a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element; Among the plurality of switching elements, one of the switching elements different from the first switching element is designated as a second switching element; a sense resistor connected to the source terminal of the sense switching element provided in the second switching element; a comparator that compares a voltage input to the sense resistor with a reference voltage and outputs a comparison result; a voltage source for inputting the reference voltage to the comparator; a driver IC connected to the comparator; In the second switching element, the first gate terminal of the sense switching element and the second gate terminal of the main switching element are short-circuited, the driver IC controls the voltage applied to the second gate terminal of the switching element based on the output from the comparator. Semiconductor device.

5. A semiconductor device in which a plurality of switching elements are connected in parallel, the switching elements including a main switching element formed of a MOSFET and a sense switching element formed of a MOSFET, the sense switching element having a smaller area in a plan view than the main switching element, and for detecting a current flowing through the main switching element, In each of the switching elements, a first gate terminal which is a gate terminal of the sense switching element is disposed between a second gate terminal which is a gate terminal of the main switching element and a source terminal of the sense switching element; one of the plurality of switching elements is designated as a first switching element, and one of the plurality of switching elements different from the first switching element is designated as a second switching element; a resistor connected to the source terminal of the sense switching element included in the first switching element; a capacitor connected to the resistor; a sense resistor connected to the source terminal of the sense switching element provided in the second switching element; a comparator that compares a voltage input to the sense resistor with a reference voltage and outputs a comparison result; a voltage source for inputting the reference voltage to the comparator; a driver IC; the first gate terminal of the sense switching element and the source terminal of the sense switching element are short-circuited, In the second switching element, the first gate terminal of the sense switching element and the second gate terminal of the main switching element are short-circuited, The driver IC controlling a voltage applied to the second gate terminal of the switching element when the voltage of the capacitor exceeds a predetermined threshold; controlling a voltage applied to the second gate terminal of the switching element based on an output from the comparator; Semiconductor device.

6. 6. The semiconductor device according to claim 1, The sense switching element is composed of a SiC-MOSFET. Semiconductor device.

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