JP2004096318A - Semiconductor device for electric power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device for electric power having an excess temperature protective function for allowing a circuit to operate stably without stopping the operation of the circuit including a switching element even if temperature in the switching element increases. <P>SOLUTION: The semiconductor device for electric power comprises at least one semiconductor switching element, a drive control circuit (22) for driving and controlling the switching element, a temperature detector (24) installed near each switching element, and a switching speed variable circuit (26). In the switching speed variable circuit (26), the switching speed of the switching element is maintained at a first speed when the temperature of the switching element is equal to or less than a specific temperature. Contrarily, when the temperature of the switching element is equal to or more than the specific temperature, the switching speed is changed to a second speed that is faster than the first one. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power semiconductor device, and more particularly, to an over-temperature protection function of a power semiconductor device.
[0002]
[Prior art]
An inverter circuit used for motor control or the like incorporates various protection circuits in order to keep its operation stable. An over-temperature protection circuit is one of them. When the temperature of an output device (a switching element such as an IGBT) of an inverter circuit is detected and the temperature becomes abnormal, the drive control circuit of the output device detects the abnormality. Tell Hereinafter, a conventional over-temperature protection circuit will be described. A general inverter circuit is a three-phase inverter circuit including six switching elements (IGBT: insulated gate bipolar transistor) and one drive control circuit for driving the switching elements.
[0003]
[Problems to be solved by the invention]
Here, a configuration of an over-temperature protection circuit for preventing thermal destruction of a certain IGBT will be described with reference to FIGS. FIG. 7 is a block diagram showing the relationship between the overtemperature protection circuit and the drive control circuit of the IGBT, and FIG. 8 is a diagram showing the internal configuration of the overtemperature protection circuit and the drive control circuit. Referring to FIG. 7, a temperature detector 104 that detects the temperature of the IGBT outputs a voltage Vt corresponding to the temperature to an over-temperature protection circuit 106. Further, the over-temperature protection circuit 106 outputs a signal P1 corresponding to the voltage Vt to the drive control circuit 102. The drive control circuit 102 outputs a drive signal to the gate of the IGBT 2 according to the signal input from the signal input terminal 108 and the signal P1.
[0004]
Referring to FIG. 8, the over-temperature protection circuit 106 includes a comparator 110. Further, the drive control circuit 102 includes a logic circuit 112 and a drive circuit 114. The comparator 110 compares the voltage Vt output from the temperature detector 104 with the reference voltage Vo, and outputs a signal P1 corresponding to the comparison result to the logic circuit 112 of the drive control circuit 102. The logic circuit 112 processes the input signal input from the signal input terminal 108 (FIG. 7) and the signal P1 input from the over-temperature protection circuit 106, and outputs the resulting signal to the drive circuit 114. The drive circuit 114 inverts the signal output from the logic circuit 112 and outputs a drive signal (voltage signal) to the gate of the IGBT.
[0005]
FIG. 9 is a time chart showing a relationship between an input signal (signal input from the signal input terminal 108) of the drive control circuit 102 and an output signal (drive signal). According to FIG. 9, when the temperature detected by the temperature detector 24 exceeds the set temperature, that is, when the value of the voltage Vt exceeds the trip level (the value of the voltage Vo) of the overcurrent protection circuit 106, the drive control circuit 102 Signal output stops. According to this configuration, when the temperature of the IGBT exceeds a certain level, the switching operation of the IGBT is stopped, and it is possible to prevent a further increase in the temperature of the IGBT.
[0006]
However, the above configuration has a problem in that the inverter operation is stopped every time the temperature of the IGBT exceeds the set temperature, and the operation of the inverter circuit becomes unstable.
[0007]
An object of the present invention is to provide a power semiconductor device having an over-temperature protection function for stably operating a circuit including a switching element without stopping operation of the circuit even when the temperature of the switching element rises. It is.
[0008]
A further object of the present invention is to realize the overtemperature protection function of the above circuit with a simpler structure.
[0009]
[Means for Solving the Problems]
A power semiconductor device according to the present invention includes one or more semiconductor switching elements, and a drive control circuit that drives and controls the switching elements. Further, the power semiconductor device may further include a temperature detector installed near each of the switching elements, wherein the switching speed of the switching element is set to a first speed when the temperature of the switching element is equal to or lower than a predetermined temperature. A switching speed variable circuit that holds the switching speed and changes the switching speed to a second speed higher than the first speed when the temperature of the switching element is higher than a predetermined temperature.
[0010]
Preferably, in the power semiconductor device, the switching speed variable circuit compares an input voltage corresponding to a temperature of the switching element with a fixed reference voltage, and the input voltage is higher than a reference voltage. A comparison circuit that outputs a first signal indicating whether the signal is large or not; Further, the drive control circuit supplies currents of different magnitudes to control terminals of the corresponding switching elements in accordance with the first signal.
[0011]
Preferably, in the power semiconductor device, the drive control circuit outputs two drive circuits that output a drive signal to the switching element, and outputs the drive signal in response to the first signal. And a switching circuit for switching the driving circuit to be performed. Further, the two driving circuits supply currents of different magnitudes from the respective output terminals to the control terminal of the switching element.
[0012]
Preferably, in the power semiconductor device, the drive control circuit includes a current source that supplies a current to a control terminal of the switching element, and an operation of the current source in response to the first signal. Driving means for starting or stopping the operation.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a configuration of a general inverter circuit. The output of the inverter circuit 10 is supplied to an electric motor (motor) 20. The inverter circuit 10 in FIG. 1 includes six switching elements (IGBTs) and one drive control circuit 22 that drives the switching elements. The drive control circuit 22 receives UPin, VPin, WPin, UNin, VNin, and WNin as input signals, and outputs drive signals UPout, VPout, WPout, UNout, VNout, and WNout to each IGBT. FIG. 2 is a block diagram illustrating an overtemperature protection function of the inverter circuit realized in the power semiconductor device according to the first embodiment. Hereinafter, as an example, a temperature protection function for preventing thermal destruction of the IGBT 2 will be described. The overtemperature protection function of the IGBT 2 described below can be applied to other IGBTs. Further, the over-temperature protection functions of the IGBTs 1 to 6 can be simultaneously activated.
[0014]
A feature of the power semiconductor device according to the present invention is that the power semiconductor device includes a switching speed variable circuit that changes a switching speed of the IGBT according to a signal output from the temperature detector.
[0015]
Referring to FIG. 2, the inverter circuit according to the present invention incorporates a temperature detector 24 for detecting the temperature of the IGBT 2. Temperature detector 24 detects the temperature of IGBT 2 and outputs voltage Vt corresponding to that temperature. The voltage Vt is input to the switching speed variable circuit 26. The switching speed variable circuit 26 outputs a signal P2 corresponding to the voltage Vt to the drive control circuit 22. The drive control circuit 22 outputs a drive signal to the gate of the IGBT 2 according to the signal input from the signal input terminal 28 and the signal P2.
[0016]
FIG. 3 is a circuit diagram showing internal circuits of the drive control circuit 22 and the switching speed variable circuit 26 of FIG. 3, the drive control circuit 22 includes a logic circuit 32, an inversion circuit 36, two switches S1 and S2, and a drive circuit 38. The drive circuit 38 includes a first drive circuit and a second drive circuit. The first drive circuit includes a p-channel MOS (metal oxide semiconductor) transistor Tr1 and an n-channel MOS transistor Tr3. The second drive circuit includes a p-channel MOS transistor Tr2 and an n-channel MOS transistor Tr3.
[0017]
In the first drive circuit, the drain (D) of the transistor Tr1 and the drain (D) of Tr3 are connected to each other. The source (S) of the transistor Tr1 is connected to the high potential power supply Vdd, and the source (S) of the transistor Tr3 is connected to the low potential power supply GND. The gate (G) of the transistor Tr1 and the gate (G) of the transistor Tr3 are connected to each other. Further, a connection point between the gate (G) of the transistor Tr1 and the gate (G) of the transistor Tr3 is connected to the switch S1 as an input terminal of the first drive circuit. A connection point between the drain (D) of the transistor Tr1 and the drain (D) of the transistor Tr3 is connected to the gate of the IGBT2 as an output terminal of the first drive circuit.
[0018]
In the second drive circuit, the drain (D) of the transistor Tr2 and the drain (D) of the transistor Tr3 are connected to each other. The source (S) of the transistor Tr2 is connected to the high potential power supply Vdd, and the source (S) of the transistor Tr3 is connected to the low potential power supply GND. The gate (G) of the transistor Tr2 and the gate (G) of the transistor Tr3 are connected to each other. Further, a connection point between the gate (G) of the transistor Tr2 and the gate (G) of the transistor Tr3 is connected to the switch S2 as an input terminal of the second drive circuit. A connection point between the drain of the transistor Tr2 and the drain of Tr3 is connected to the gate of the IGBT2 as an output terminal of the second drive circuit. Here, the transistor Tr1 and the transistor Tr2 are connected in parallel, and the transistor Tr3 is connected in series to the transistors Tr1 and Tr2, respectively.
[0019]
The input terminal of the logic circuit 32 is connected to the output terminal of the signal input terminal 28 (FIG. 2). The logic circuit 32 processes a signal input from the signal input terminal 28 (FIG. 2) to the drive control circuit 22, and outputs a signal corresponding to the input signal. The output terminal of the logic circuit 32 is connected to the switch S1 and the switch S2. The signal (voltage signal) output from the logic circuit 32 is input to the first drive circuit when the switch S1 is turned on and the switch S2 is turned off, and when the switch S1 is turned off and the switch S2 is turned on. , To the second drive circuit.
[0020]
For example, when the switch S1 is turned on and the switch S2 is turned off, a signal output from the logic circuit 32 is input to the gate (G) of the transistor Tr1 and the gate (G) of the transistor Tr3. When the signal output from the logic circuit 32 changes from a high level (“H” level) to a low level (“L” level), the p-channel MOS transistor Tr1 turns on and the n-channel MOS transistor Tr3 turns off. At this time, the output signal (voltage signal) of the first drive circuit becomes equal to the potential of the high potential power supply Vdd. On the other hand, when the signal output from the logic circuit 32 changes from a low level (“L” level) to a high level (“H” level), the p-channel MOS transistor Tr1 turns off and the n-channel MOS transistor Tr3 turns on. . At this time, the output signal (voltage signal) of the first drive circuit becomes equal to the potential of the low potential power supply GND. The above operation is performed when the switch S1 is turned off and the switch S2 is turned on, that is, the signal output from the logic circuit 32 is input to the gate (G) of the transistor Tr2 and the gate (G) of the transistor Tr3. In this case, the present invention can also be applied to the second drive circuit.
[0021]
Here, the transistor Tr1 and the transistor Tr2 are different in size (strictly, the size of the gate electrode). Therefore, even if the same voltage is input to the gate, the magnitude of the current flowing through each transistor is different. In the circuit of FIG. 3, the size of the transistor Tr1 is larger than that of the transistor Tr2. That is, the transistor Tr1 has a high current supply capability, and the transistor Tr2 has a low current supply capability.
[0022]
The switching speed variable circuit 26 includes a comparator 34. Further, the switching speed variable circuit 26 requires the switches S1 and S2 and the inverting circuit 36 constituting the drive control circuit 22 for driving thereof, and includes these as a part of the components. The comparator 34 compares the voltage Vt output from the temperature detector 24 with the reference voltage Vo, and outputs a signal P2 according to the comparison result. This signal P2 is transmitted to the switch S1 as it is, and is transmitted to the switch S2 after being inverted by the inverting circuit 36. Here, FIG. 4 is a timing chart showing the relationship between the detected temperature and the signals transmitted to the switches S1 and S2. The switches S1 and S2 are turned on when a high-level signal is transmitted, and are turned off when a low-level signal is transmitted. If the temperature detected by the temperature detector 24 exceeds the set temperature, the value of the voltage Vt becomes larger than the value of the reference voltage Vo, and the output signal P2 of the comparator 34 goes high. Then, a high-level signal is transmitted to the switch S1, and a low-level signal is transmitted to the switch S2. As a result, the switch S1 turns on and the switch S2 turns off. On the other hand, if the detected temperature does not exceed the set temperature, the output signal P2 of the comparator 34 goes low, so that the low level signal and the high level signal are transmitted to the switches S1 and S2, respectively. , Switch S1 is turned off, and switch S2 is turned on.
[0023]
When the switch S1 is turned on and the switch S2 is turned off, the output signal of the logic circuit 32 is input to the first drive circuit. Since the first drive circuit includes the p-channel MOS transistor Tr1 having a high current supply capability, when the first drive circuit is driven, the output terminal of the drive circuit (the connection point between the drain of the transistor Tr1 and the drain of Tr3) ), The current flowing into the gate terminal of the IGBT 2 increases. Here, the IGBT 2 is a voltage-driven element, but when used as a power element in an inverter circuit, the parasitic capacitance between the gate and the source cannot be ignored and charges the parasitic capacitance before the IGBT 2 is turned on. There is a need. Therefore, in this case, when the gate current flowing into the IGBT 2 is large, the time for charging the gate-source capacitance is shortened, and the switching speed of the IGBT 2 is increased. With the above configuration, when the temperature of the IGBT 2 rises above a certain level, the switching speed of the IGBT 2 increases, and as a result, the temperature of the IGBT 2 can be prevented from further rising.
[0024]
On the other hand, if the temperature of the IGBT 2 becomes lower than a certain level, the switch S1 turns off and the switch S2 turns on, so that the output signal of the logic circuit 32 is input to the second drive circuit. Since the second drive circuit includes the p-channel MOS transistor Tr2 having a low current supply capability, the gate current flowing into the IGBT 2 is smaller than when the first drive circuit is driven. As a result, the time for charging the parasitic capacitance of the IGBT becomes longer, and the switching speed of the IGBT 2 becomes slower than when the first drive circuit is driven.
[0025]
In the inverter circuit according to the present embodiment, IGBT 2 operates at a normal switching speed when the temperature is below a certain level, but operates at a higher switching speed when the temperature exceeds a certain level. Therefore, when the temperature of the IGBT 2 exceeds the set temperature, a further rise in temperature can be prevented, and as a result, thermal destruction of the IGBT 2 can be prevented.
[0026]
Further, in the inverter circuit according to the present embodiment, two drive circuits (a first drive circuit and a second drive circuit) are connected in parallel with two p-channel MOS transistors and the transistors are connected in series. Since the two drive circuits are constituted by the n-channel MOS transistors, the overtemperature protection function of the inverter circuit can be more easily realized as compared with the case where these two drive circuits are constituted by separate components.
[0027]
Further, in the inverter circuit according to the present embodiment, a structure in which two driving circuits (a first driving circuit and a second driving circuit) are switched in accordance with an output signal of a comparator includes two switches and one NOT circuit. (Inverting circuit), the overtemperature protection function of the inverter circuit can be realized more easily.
[0028]
In the inverter circuit according to the present embodiment, switches S1 and S2 that open and close according to a signal transmitted from comparator 34 may be semiconductor switching elements. In that case, the signal output from the comparator 34 is input to the control terminal of the semiconductor switching element.
[0029]
Note that, in the inverter circuit according to the present embodiment, the two drive circuits (the first drive circuit and the second drive circuit) in the drive control circuit 22 are not limited to the configuration described above, and may have another configuration using a MOS transistor. It may be. Further, the two drive circuits may have the same configuration or different configurations. Even in those cases, the same effect can be obtained if the two drive circuits can supply gate currents of different magnitudes to the IGBT 2. Further, the above two driving circuits can be realized by using bipolar transistors.
[0030]
Embodiment 2 FIG.
FIG. 5 is a circuit diagram showing internal circuits of the drive control circuit 42 and the switching speed variable circuit 46 in the inverter circuit. The power semiconductor device according to the present embodiment differs from the power semiconductor device according to the first embodiment in the configuration of the drive circuit 38 and the switches in the drive control circuit 42. 5, the drive control circuit 42 includes a logic circuit 32, a single switch S3, and a drive circuit 38. The drive circuit 38 includes a third drive circuit including a p-channel MOS transistor Tr4 and an n-channel MOS transistor Tr6, and a p-channel transistor Tr5 connected in parallel to the transistor Tr4. The switching speed variable circuit 46 includes the comparator 34. Further, the switching speed variable circuit 46 requires a switch S3 constituting the drive control circuit 42 for driving thereof, and the switch S3 is included as a part of the components.
[0031]
In the third driving circuit, the drain (D) of the transistor Tr4 and the drain (D) of Tr6 are connected to each other. The source (S) of the transistor Tr4 is connected to the high potential power supply Vdd, and the source (S) of the transistor Tr6 is connected to the low potential power supply GND. The gate (G) of the transistor Tr4 and the gate (G) of the transistor Tr6 are connected to each other. Further, a connection point between the gate (G) of the transistor Tr4 and the gate (G) of the transistor Tr6 is connected to an output terminal of the logic circuit 32 as an input terminal of the third drive circuit. A connection point between the drain (D) of the transistor Tr4 and the drain (D) of the transistor Tr6 is connected to the gate of the IGBT 2 as an output terminal of the third drive circuit. The operation of the third drive circuit is the same as the operation of the first drive circuit described in Embodiment 1, and thus the description is omitted.
[0032]
The transistor Tr5 is connected in parallel with the transistor Tr4, and is connected in series with the transistor Tr6. The source (S) of the transistor Tr5 is connected to the high potential power supply Vdd, and the drain (D) of the transistor Tr5 is connected to the drain (D) of Tr6. The switch S3 is connected to the gate (G) of the transistor Tr5. Further, a connection point between the drain (D) of the transistor Tr5 and the drain (D) of the transistor Tr6 is connected to the gate of the IGBT2.
[0033]
In the drive control circuit 42, the signal (voltage signal) output from the logic circuit 32 is always input to the third drive circuit including the transistors Tr4 and Tr6. That is, the signal (voltage signal) output from the logic circuit 32 is input to the gate (G) of the transistor Tr4 and the gate (G) of the transistor Tr6. Further, when the switch S3 is turned on, the signal output from the logic circuit 32 is also input to the gate of the p-channel MOS transistor Tr5. The switch S3 is turned on or off according to a signal output from the comparator 34. Specifically, the switch S3 turns on when the signal output from the comparator 34 is at a high level, and turns off when the signal is at a low level. The drive signal output from the third drive circuit is input to the gate of IGBT2.
[0034]
When the temperature of the IGBT 2 exceeds a certain level, the value of the voltage Vt output from the temperature detector 24 becomes larger than the value of the reference voltage Vo, and the comparator 34 outputs a high-level output signal P2. The signal P2 is transmitted to the switch S3, and the switch S3 is turned on. FIG. 6 is a timing chart showing the relationship between the detected temperature and the signal transmitted to the switch S3. The switch S3 turns on when a high-level signal is transmitted, and turns off when a low-level signal is transmitted. When the switch S3 is turned on, the output signal of the logic circuit 32 is also input to the gate of the p-channel MOS transistor Tr5. At this time, the drain current flows through the transistor Tr5 and merges with the output current of the third drive circuit, so that the gate current of the IGBT 2 increases. As a result, when the temperature of the IGBT 2 exceeds the set temperature, the switching speed of the IGBT 2 increases as described in the first embodiment. On the other hand, if the temperature of the IGBT 2 becomes lower than a certain level, the value of the voltage Vt becomes smaller than the value of the reference voltage Vo, so that the output signal P2 of the comparator 34 becomes low and the switch S3 is turned off. When the switch S3 turns off, the transistor Tr5 turns off. As a result, the gate current of the IGBT 2 becomes only the output current of the third drive circuit, and the switching speed decreases.
[0035]
In the inverter circuit according to the present embodiment, when the temperature of IGBT 2 exceeds a certain level, the switching speed of IGBT 2 increases. As a result, a further increase in the temperature of the IGBT 2 can be prevented, and as a result, thermal destruction of the IGBT 2 can be prevented.
[0036]
In the inverter circuit according to the present embodiment, the current source for charging the parasitic capacitance of IGBT 2 is a p-channel MOS transistor, and when it is desired to drive the current source, its control terminal is connected to the logic terminal from the logic circuit. Since the output signal is input, the over-temperature protection function of the inverter circuit can be realized more easily.
[0037]
Further, in the inverter circuit according to the present embodiment, since the structure for driving the current source in accordance with the output signal of the comparator is realized by a single switch, the overtemperature protection function of the inverter circuit can be more easily performed. realizable.
[0038]
In the inverter circuit according to the present embodiment, the switch S3 that opens and closes according to the signal transmitted from the comparator 34 may be a semiconductor switching element. In that case, the signal output from the comparator 34 is input to the control terminal of the semiconductor switching element.
[0039]
Note that, in the inverter circuit according to the present embodiment, the third drive circuit in the drive control circuit 42 is not limited to the configuration described above, and may have another configuration using MOS transistors. Further, the third driving circuit can be realized by using a bipolar transistor.
[0040]
In the inverter circuit according to the present embodiment, the current source for charging the parasitic capacitance of the IGBT 2 with the p-channel MOS transistor is realized, but other components may be used. Even in such a case, the same effect can be obtained if an additional current can be supplied to the gate of the IGBT 2.
[0041]
Although the over-temperature protection functions of the IGBT 2 have been described above, these over-temperature protection functions can be applied to other IGBTs. Further, the over-temperature protection functions of the IGBTs 1 to 6 can be simultaneously activated.
[0042]
In the above-described embodiment, the switching element is an IGBT, but may be another voltage-driven semiconductor switching element.
[0043]
Although the inverter circuit has been described in the above embodiment, the overtemperature protection function of the present invention can be applied to another circuit having a switching element and a drive control circuit for driving the switching element.
[0044]
【The invention's effect】
According to a first power semiconductor device of the present invention, a power module including one or more semiconductor switching elements, a drive control circuit for driving and controlling the power module, and further provided near each of the switching elements A temperature detector and a switching speed variable circuit for changing a switching speed in accordance with the temperature of each of the switching elements, so that the switching element performs normal switching when the temperature is below a certain level. It operates at a speed, and when the temperature exceeds a certain level, it is possible to operate at a higher switching speed. Therefore, when the temperature of the switching element exceeds the set temperature, a further rise in temperature can be prevented, and as a result, thermal destruction of the switching element can be prevented.
[0045]
According to the second power semiconductor device of the present invention, the switching speed variable circuit compares the input voltage corresponding to the temperature of the switching element with a constant reference voltage, and the input voltage is higher than the reference voltage. A driving circuit for supplying a current of a different magnitude to the control terminal of the switching element according to the first signal. When a certain level is exceeded, it is possible to increase the switching speed of the switching element. Thereby, the temperature of the switching element can be prevented from further increasing, and as a result, the thermal destruction of the switching element can be prevented.
[0046]
According to the third power semiconductor device of the present invention, the drive control circuit includes two signal inversion circuits for inverting and outputting the control signal to the switching element, and a control signal in response to the first signal. A switching circuit for switching the input signal inverting circuit. Since the two signal inverting circuits supply currents of different magnitudes from the respective output terminals to the control terminal of the switching element, the temperature of the switching element reaches a certain level. If it exceeds, the switching speed of the switching element can be increased. Thereby, the temperature of the switching element can be prevented from further increasing, and as a result, the thermal destruction of the switching element can be prevented.
[0047]
According to the fourth power semiconductor device of the present invention, the drive control circuit starts or stops the operation of the current source according to the first signal and the current source that supplies the current to the control terminal of the switching element. Since the driving means is provided, when the temperature of the switching element exceeds a certain level, the switching speed of the switching element can be increased. Thereby, the temperature of the switching element can be prevented from further increasing, and as a result, the thermal destruction of the switching element can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a general inverter module power module.
FIG. 2 is a block diagram illustrating an overtemperature protection function of the inverter circuit according to the first embodiment.
FIG. 3 is a circuit diagram showing internal circuits of the drive control circuit and the switching speed variable circuit of FIG. 2;
FIG. 4 is a timing chart showing a relationship between a detected temperature of the IGBT and a signal transmitted to a switch in a drive control circuit.
FIG. 5 is a circuit diagram showing an internal circuit of a drive control circuit and a switching speed variable circuit according to a second embodiment.
FIG. 6 is a timing chart showing a relationship between a detected temperature of the IGBT and a signal transmitted to a switch in the drive control circuit.
FIG. 7 is a block diagram illustrating an overtemperature protection function of a conventional inverter circuit.
FIG. 8 is a diagram showing an internal configuration of a drive control circuit and an over-temperature protection circuit of FIG. 7;
FIG. 9 is a time chart illustrating a relationship between an input signal and an output signal of the drive control circuit.
[Explanation of symbols]
22 drive control circuit, 24 temperature detector, 26 switching speed variable circuit, 28 signal input terminal

Claims (4)

One or more semiconductor switching elements;
A power semiconductor device comprising: a drive control circuit that drives and controls the switching element.
further,
A temperature detector installed near each of the switching elements,
When the temperature of the switching element is equal to or lower than a predetermined temperature, the switching speed of the switching element is held at a first speed, and when the temperature of the switching element is higher than a predetermined temperature, the switching speed is set higher than the first speed. A variable switching speed circuit for changing to a faster second speed. The switching speed variable circuit compares an input voltage corresponding to the temperature of the switching element with a fixed reference voltage, and outputs a first signal indicating whether the input voltage is higher than a reference voltage. Circuit,
2. The power semiconductor device according to claim 1, wherein the drive control circuit supplies currents of different magnitudes to control terminals of the corresponding switching elements in accordance with the first signal. 3. The drive control circuit,
Two drive circuits for outputting a drive signal to the switching element;
A switching circuit that switches a driving circuit that outputs the driving signal according to the first signal;
3. The power semiconductor device according to claim 2, wherein the two driving circuits supply currents of different magnitudes from respective output terminals to a control terminal of the switching element. The drive control circuit,
A current source for supplying a current to a control terminal of the switching element;
3. The power semiconductor device according to claim 2, further comprising: a driving unit that starts or stops the operation of the current source in response to the first signal. 4.

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