Temperature detection method for voltage-controlled semiconductor element and driving device

Abstract

This invention provides high-precision temperature monitoring of the semiconductor chip of a voltage-controlled semiconductor device. A delay circuit (28) delays the drive signal SDRV output from the drive circuit (24), ensuring that the rising edge of the delayed signal reaches the Miller effect period when the IGBT (10) is turned on. A single trigger circuit (30) receives the delayed signal and outputs a pulse signal with a pulse width shorter than the Miller effect period. A comparator (36) compares the gate voltage VGE with a reference voltage Vref, which corresponds to the overheat detection threshold voltage. If the gate voltage VGE exceeds the overheat detection threshold voltage, an overheat detection signal is output. By monitoring the gate voltage VGE, which is temperature-dependent on the chip temperature of the IGBT (10), the chip temperature of the IGBT (10) is directly monitored.

Description

Technical Field

[0001] This invention relates to a method for detecting the chip temperature of a voltage-controlled semiconductor device, and a driving device for the voltage-controlled semiconductor device having the function of outputting the detected chip temperature to the outside. Background Technology

[0002] There exist semiconductor devices that control the switching of inductive loads or perform power conversion. Such semiconductor devices include semiconductor switching elements and driving devices that drive these semiconductor switching elements. As semiconductor switching elements, voltage-controlled semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are used.

[0003] Voltage-controlled semiconductor devices define their permissible temperature using absolute maximum ratings. If a voltage-controlled semiconductor device operates above its maximum permissible temperature, thermal damage to the semiconductor chip may occur. To prevent or mitigate this thermal damage, the chip temperature is monitored, and if the chip temperature is anticipated to be high, the voltage-controlled semiconductor device is operated or stopped below its rated value.

[0004] As a method for detecting the chip temperature of a voltage-controlled semiconductor device, it is known to include a thermistor in the semiconductor device, detect the temperature inside the casing, and predict the chip temperature based on operating conditions. Alternatively, a temperature sensing diode is integrally formed on the chip of the voltage-controlled semiconductor device, and the chip temperature is directly measured based on the temperature characteristics of the temperature sensing diode.

[0005] Chip temperature prediction methods based on thermistors have the characteristic that, because the thermistors are mounted far from the semiconductor chip, they cannot keep up with rapid temperature rises caused by changes in current flow due to load variations. On the other hand, in chip temperature measurement methods based on temperature sensing diodes, the active area is reduced because the temperature sensing diode is fabricated on the semiconductor chip, and further reduced because a dedicated diode electrode is placed on the semiconductor chip. Therefore, when a temperature sensing diode is mounted on a semiconductor switching element chip with a small current rating, the chip size becomes larger.

[0006] Therefore, a method for detecting the temperature of a voltage-controlled semiconductor chip without using a thermistor or a temperature sensing diode has been proposed (for example, see Patent Document 1 and Patent Document 2).

[0007] According to the technology described in Patent Document 1, the temperature is detected by measuring the duration of the Miller plateau when the IGBT is turned off and converting the duration of the Miller plateau into a temperature. That is, in the technology of Patent Document 1, the IGBT junction temperature is determined based on the interdependence between the Miller plateau time delay and the IGBT junction temperature.

[0008] In the technology of Patent Document 2, the time change of the gate voltage during the switching operation of a semiconductor device is measured, and the temperature of the semiconductor device is estimated based on the temperature dependence of the time change of the gate voltage on the temperature of the semiconductor device.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2013-142704

[0012] Patent Document 2: Japanese Patent Application Publication No. 2020-072569 Summary of the Invention

[0013] Technical issues

[0014] However, the technology in Patent Document 1 has the problem of difficulty in accurately detecting the Miller effect period, which is the time delay of the Miller plateau. Furthermore, the technology in Patent Document 2 involves measuring the gate voltage rise time and using a microcomputer to calculate the temperature of the semiconductor device corresponding to the gate voltage rise time, based on temperature dependence information; therefore, this leads to the problem of increasing the size of the driving device.

[0015] The present invention was made in view of the following point, and its object is to provide a temperature detection method and driving device for large-scale voltage-controlled semiconductor devices that can perform temperature monitoring of semiconductor chips with high accuracy and are not used for temperature detection of semiconductor chips.

[0016] Technical solution

[0017] In order to solve the above-mentioned problems, one aspect of this invention provides a temperature detection method for a voltage-controlled semiconductor device. In this method, the gate voltage of the gate used to drive the voltage-controlled semiconductor device is monitored, the voltage during the Miller effect period generated when the gate voltage changes instantaneously during the turn-on or turn-off of the voltage-controlled semiconductor device is detected, and the gate voltage during the Miller effect period is output as a signal that is temperature-dependent on the chip temperature of the voltage-controlled semiconductor device.

[0018] Furthermore, the present invention provides a driving device for a voltage-controlled semiconductor device. This driving device for the voltage-controlled semiconductor device includes: a driving circuit that drives the gate of the voltage-controlled semiconductor device; a gate resistor disposed between the driving circuit and the gate of the voltage-controlled semiconductor device; a delay circuit that delays a driving signal output by the driving circuit until a predetermined time is reached, up to the Miller effect period generated during a momentary change in the gate voltage; a single trigger circuit that outputs a pulse signal having a pulse width shorter than the Miller effect period from the rising edge or falling edge of the delayed signal output by the delay circuit; a comparator that compares a gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor device, with a reference voltage equivalent to an overheat detection threshold voltage; and a receiving circuit that receives the pulse signal output by the single trigger circuit and the output signal of the comparator, and outputs an overheat detection signal if the gate voltage exceeds the reference voltage.

[0019] The present invention also provides a driving device for another voltage-controlled semiconductor device. This driving device for the voltage-controlled semiconductor device includes: a driving circuit that drives the gate of the voltage-controlled semiconductor device; a gate resistor disposed between the driving circuit and the gate of the voltage-controlled semiconductor device; a delay circuit that delays the driving signal output by the driving circuit until a predetermined time is reached up to the Miller effect period generated during the instantaneous change of the gate voltage; a single trigger circuit that outputs a pulse signal having a pulse width shorter than the Miller effect period from the rising edge or falling edge of the delayed signal output by the delay circuit; and a sample-and-hold circuit that acquires a gate voltage that is temperature-dependent on the chip temperature of the voltage-controlled semiconductor device during the reception of the pulse signal, holds the gate voltage when the input of the pulse signal disappears, and outputs it.

[0020] In addition, the present invention provides another driving device for a voltage-controlled semiconductor device. This driving device for the voltage-controlled semiconductor device includes: a driving circuit that drives the gate of the voltage-controlled semiconductor device; a gate resistor disposed between the driving circuit and the gate of the voltage-controlled semiconductor device; a delay circuit that delays the driving signal output by the driving circuit until a predetermined time is reached up to the Miller effect period generated during the instantaneous change of the gate voltage; a single trigger circuit that outputs a pulse signal having a pulse width shorter than the Miller effect period from the rising edge or falling edge of the delayed signal output by the delay circuit; a comparator that compares a gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor device, with a reference voltage equivalent to an overheat detection threshold voltage; a sampling and holding circuit that receives the pulse signal output by the single trigger circuit and the output signal of the comparator, and outputs an overheat detection signal if the gate voltage exceeds the reference voltage; and a sample-and-hold circuit that acquires the gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor device, during the reception of the pulse signal, holds the gate voltage when the input of the pulse signal disappears, and outputs it.

[0021] Technical effect

[0022] Since the temperature detection method and driving device of the voltage-controlled semiconductor element described above can directly and in real time monitor the chip temperature of the voltage-controlled semiconductor element, the chip temperature can be monitored with high accuracy. In addition, the configuration for detecting chip temperature can be implemented with a small-scale circuit configuration.

[0023] The above and other objects, features and advantages of the present invention become apparent from the accompanying drawings, which illustrate preferred embodiments as examples of the invention, and the following description in connection with them. Attached Figure Description

[0024] Figure 1 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the first embodiment.

[0025] Figure 2 This is a graph showing the relationship between gate voltage and chip temperature during the Miller effect.

[0026] Figure 3 This is a timing diagram illustrating the operation of the IGBT drive device according to the first embodiment.

[0027] Figure 4 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the second embodiment.

[0028] Figure 5 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the third embodiment.

[0029] Symbol Explanation

[0030] 10: IGBT

[0031] 12: FWD

[0032] 20, 20a, 20b: Drive unit

[0033] 22: Pre-driver

[0034] 24: Drive circuit

[0035] 26: Gate resistor

[0036] 28: Delay circuit

[0037] 30: Single trigger circuit

[0038] 32, 34: Resistors

[0039] 36: Comparator

[0040] 38: With circuit

[0041] 40: Sample and Hold Circuit

[0042] 42: Operational amplifier

[0043] 44: Switching elements

[0044] 46: Capacitor

[0045] 48: Operational amplifier Detailed Implementation

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, taking the case of using an IGBT as a voltage-controlled semiconductor element and applying it to a drive device for driving the IGBT. It should be noted that in the drawings, parts indicated by the same symbols represent the same constituent elements.

[0047] Figure 1 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the first embodiment. Figure 2 This is a graph showing the relationship between gate voltage and chip temperature during the Miller effect. Figure 3 This is a timing diagram illustrating the operation of the IGBT drive device according to the first embodiment.

[0048] exist Figure 1 The diagram shows an IGBT 10 as a semiconductor switching element and a drive device 20 for driving the IGBT 10. The IGBT 10 and the drive device 20 are, for example, integrated into a package to form a semiconductor device called a smart power module.

[0049] IGBT 10 is connected in reverse parallel with an FWD (Free Wheeling Diode) 12. The FWD 12 serves to allow the energy stored in the inductive load to flow back to the power supply side when IGBT 10 is turned off. That is, the anode of the FWD 12 is connected to the emitter of IGBT 10, and the cathode of the FWD 12 is connected to the collector of IGBT 10.

[0050] The drive unit 20 includes a pre-driver 22, a drive circuit 24, and a gate resistor 26. The pre-driver 22 has a terminal IN for receiving PWM (Pulse Width Modulation) signals from an external upstream device. The output terminal of the pre-driver 22 is connected to the input terminal of the drive circuit 24. The output terminal of the drive circuit 24 is connected to one terminal of the gate resistor 26, and the other terminal of the gate resistor 26 is connected to terminal G, which is connected to the gate of the IGBT 10. The drive circuit 24 is also connected to terminal E, which is connected to the emitter of the IGBT 10. The PWM signal input to terminal IN is converted into a drive signal SDRV by the pre-driver 22 and the drive circuit 24. The drive signal SDRV is converted into a gate voltage VGE by the gate resistor 26 and supplied to terminal G.

[0051] The drive unit 20 also includes a delay circuit 28, a single trigger circuit 30, resistors 32 and 34, a comparator 36, and an AND circuit 38. The input terminal of the delay circuit 28 is connected to the connection between the output terminal of the drive circuit 24 and one terminal of the gate resistor 26, and the output terminal of the delay circuit 28 is connected to the input terminal of the single trigger circuit 30. One terminal of resistor 32 is connected to the power supply line, and the other terminal of resistor 32 is connected to one terminal of resistor 34, with the other terminal of resistor 34 grounded. Resistors 32 and 34 form a voltage divider circuit and output a reference voltage Vref. The reference voltage Vref is equivalent to the overheat detection threshold voltage, for example, the voltage equivalent to the upper limit of the operating temperature guarantee temperature of IGBT 10, i.e., 175°C.

[0052] The non-inverting input terminal of comparator 36 is connected to the connection between the other terminal of gate resistor 26 and terminal G, and the inverting input terminal is connected to the connection between the other terminal of resistor 32 and one terminal of resistor 34. The output terminal of single-trigger circuit 30 is connected to the first input terminal of circuit 38, and the output terminal of comparator 36 is connected to the second input terminal of circuit 38. The output terminal of circuit 38 is connected to the alarm output terminal ALM, which notifies an external upper-level device of an overheat detection signal.

[0053] Here, the gate voltage VGE during the Miller effect period when the IGBT 10 is turned on is temperature-dependent on the chip temperature Tvj of the IGBT 10. For example... Figure 2As shown, since its temperature dependence is a linear change in the gate voltage VGE with respect to the chip temperature Tvj, the chip temperature Tvj can be detected based on the gate voltage VGE.

[0054] Next, refer to Figure 3 The timing diagram illustrates the operation of the drive unit 20 configured above. It should be noted that... Figure 3 In the timing diagram, from top to bottom, the following signals are shown: the drive signal SDRV output by the drive circuit 24, the gate voltage VGE between the gate resistor 26 and the terminal G, the delay signal output by the delay circuit 28, the pulse signal output by the single trigger circuit 30, and the overheat detection signal of the alarm output terminal ALM.

[0055] If a PWM signal is input to terminal IN of drive device 20, the PWM signal is input to drive circuit 24 via pre-driver 22 and output from drive circuit 24 as drive signal SDRV. If the drive signal SDRV is applied to the gate of IGBT 10 via gate resistor 26, the gate voltage VGE is as follows: Figure 3 Make the changes as shown.

[0056] If the drive signal SDRV rises from a low (L) level to a high (H) level, the H-level voltage charges the gate-emitter capacitance of IGBT 10 through the gate resistor 26. If the charging voltage of the gate-emitter capacitance exceeds the turn-on threshold voltage of IGBT 10, IGBT 10 turns on, and the collector-emitter junction of IGBT 10 becomes approximately short-circuited. Thus, with the gate of IGBT 10 connected to both the gate-emitter capacitance and the gate-collector capacitance (Miller capacitance), IGBT 10 operates as a Miller integrator. During the Miller effect period Tm, which is its operating period, the gate voltage VGE remains constant. If the Miller effect period Tm ends, further charging continues to the gate of IGBT 10, and therefore, the gate voltage VGE rises to the H level of the drive signal SDRV.

[0057] After the drive signal SDRV becomes L level, the gate voltage VGE changes in the opposite direction to the change when IGBT 10 is turned on, and the gate voltage VGE drops to the potential that becomes L level of the drive signal SDRV.

[0058] The drive signal SDRV is also input to the delay circuit 28. The delay circuit 28 outputs a delayed signal, which delays the drive signal SDRV by a delay time Td. This delay time Td is the time from the rising edge of the drive signal SDRV to any point in time during the Miller effect period Tm of the gate voltage VGE, and is determined based on the switching characteristics of the IGBT 10. The delayed signal is input to the single trigger circuit 30, which outputs a pulse signal of a certain width from the rising edge of the delayed signal. The pulse signal output by the single trigger circuit 30 has a pulse width shorter than the Miller effect period Tm, and becomes the signal for obtaining the gate voltage VGE during the Miller effect period Tm.

[0059] The gate voltage VGE is also provided to the non-inverting input terminal of comparator 36. Since comparator 36 receives a reference voltage Vref, equivalent to the overheat detection threshold voltage, at its inverting input terminal, it constitutes a binarized circuit for determining whether the gate voltage VGE reaches the overheat detection threshold voltage. Comparator 36 outputs an L-level signal when the gate voltage VGE is less than the reference voltage Vref, and an H-level signal when the gate voltage VGE is greater than or equal to the reference voltage Vref.

[0060] The first input terminal of the circuit 38 receives the pulse signal output by the single-trigger circuit 30, and the second input terminal receives the output signal of the comparator 36. Thus, the circuit 38 allows the output signal of the comparator 36 to pass through only during the period when it is receiving the pulse signal.

[0061] When the chip temperature of IGBT 10 is within the range of the operating guarantee temperature, the gate voltage VGE of Tm during the Miller effect is less than the reference voltage Vref, so comparator 36 outputs an L-level signal, and therefore, circuit 38 outputs an L-level signal.

[0062] When the IGBT 10 chip temperature exceeds the guaranteed operating temperature range, due to the Miller effect, the gate voltage VGE of Tm becomes above the reference voltage Vref. Therefore, comparator 36 outputs a signal of level H, which is also output by circuit 38. This signal of level H serves as an overheat detection signal and is sent to the external upper-level device from the alarm output terminal ALM.

[0063] It should be noted that, in this embodiment, although the overheat detection signal is output to the outside from the alarm output terminal ALM, it can also be input to an overheat detection protection circuit (not shown) to forcibly turn off IGBT 10.

[0064] Figure 4 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the second embodiment.

[0065] The driving device 20a of the IGBT 10 in the second embodiment is configured such that, in contrast to the driving device 20 of the first embodiment which detects overheating of the IGBT 10 and outputs an alarm, the driving device 20a detects the chip temperature in real time and outputs it.

[0066] The drive device 20a includes a pre-driver 22, a drive circuit 24, a gate resistor 26, a delay circuit 28, and a single trigger circuit 30. These are the same circuit units as those included in the drive device 20 of the first embodiment, so detailed descriptions are omitted here.

[0067] The drive unit 20a also includes a sample-and-hold circuit 40. The sample-and-hold circuit 40 includes an operational amplifier 42, a switching element 44, a capacitor 46, and an operational amplifier 48. The inverting input terminal of the operational amplifier 42 is connected to its own output terminal to form a voltage follower circuit, and the non-inverting input terminal is connected to terminal G, which is connected to the gate of the IGBT 10. The output terminal of the operational amplifier 42 is connected to one terminal of the switching element 44, and the other terminal of the switching element 44 is connected to one terminal of the capacitor 46 and the non-inverting input terminal of the operational amplifier 48. The other terminal of the capacitor 46 is grounded. The control terminal of the switching element 44 is connected to the output terminal of the single trigger circuit 30. The inverting input terminal of the operational amplifier 48 is connected to its own output terminal to form a voltage follower circuit. The output terminal of the operational amplifier 48 is connected to the chip temperature output terminal TMP.

[0068] The sample-and-hold circuit 40 of the drive device 20a is configured to receive the gate voltage VGE through an operational amplifier 42 with high input impedance, thereby minimizing the impact caused by connecting the sample-and-hold circuit 40 to terminal G. Since the operational amplifier 42 is configured as a voltage follower circuit, the gate voltage VGE input to the non-inverting input terminal is directly output. If the switching element 44 receives a pulse signal of level H output by the single trigger circuit 30 at the control terminal, it is turned on (conducted) only during the period of receiving the pulse signal, and the voltage output by the operational amplifier 42 (≈ gate voltage VGE) is applied to the capacitor 46. At this time, the terminal voltage of the capacitor 46 becomes the voltage obtained by following the voltage output by the operational amplifier 42.

[0069] If the pulse signal output by the single trigger circuit 30 becomes L level, then the switching element 44 is turned off (non-conducting), and the terminal voltage of the capacitor 46 remains at the voltage when the switching element 44 is turned off. The voltage held by the capacitor 46 is directly output as the chip temperature detection signal through the operational amplifier 48 that constitutes the voltage follower circuit, and is notified to the external upper-level device from the chip temperature output terminal TMP.

[0070] It should be noted that in the external upstream device, if a chip temperature detection signal is received from the drive device 20a, the chip temperature is calculated based on the chip temperature detection signal. That is, the upstream device has a display... Figure 2 The data showing the relationship between the gate voltage VGE and the chip temperature Tvj during the Miller effect is used to convert the gate voltage VGE shown in the chip temperature detection signal into the corresponding chip temperature Tvj.

[0071] Therefore, for the drive device 20a, since it can directly and in real time monitor the chip temperature of the IGBT 10, it can monitor the chip temperature with high accuracy. In addition, it can implement the configuration for detecting the chip temperature with a small-scale circuit configuration.

[0072] Figure 5 This is a circuit diagram showing an example of the configuration of the IGBT drive device according to the third embodiment.

[0073] The driving device 20b of the IGBT 10 in the third embodiment has the overheat detection function of the IGBT 10 of the driving device 20 in the first embodiment and the chip temperature detection function of the IGBT 10 of the driving device 20a in the second embodiment.

[0074] The driving device 20b includes a pre-driver 22, a driving circuit 24, a gate resistor 26, a delay circuit 28, a single trigger circuit 30, resistors 32 and 34, a comparator 36, an AND circuit 38, and a sample-and-hold circuit 40. The components of the driving device 20b described above are the same as those of the driving device 20 of the first embodiment and the driving device 20a of the second embodiment. However, the gate voltage VGE input to the non-inverting input terminal of the comparator 36 is obtained from the output terminal of the operational amplifier 42 of the sample-and-hold circuit 40.

[0075] Thus, the drive device 20b has the same circuit units as the drive device 20 of the first embodiment and the drive device 20a of the second embodiment, and its operation is also the same as that of the drive devices 20 and 20a, so detailed description is omitted here. According to this drive device 20b, both overheat detection and temperature detection can be achieved.

[0076] It should be noted that in the above embodiment, the gate voltage VGE during the Miller effect period when the IGBT 10 is turned on is detected, and the chip temperature corresponding to the gate voltage VGE is determined. However, it is also possible to change this to detecting the gate voltage VGE during the Miller effect period when the IGBT 10 is turned off, or during both the turn-on and turn-off periods of the IGBT 10, and then determining the chip temperature. In this case, the delay circuit 28 outputs a delayed signal that is delayed from the time point of the falling edge of the drive signal SDRV to any time point within the Miller effect period Tm of the gate voltage VGE. Furthermore, the drive devices 20 and 20a can be replaced by devices that drive MOSFETs instead of the IGBT 10.

[0077] The above describes one aspect of the temperature detection method and driving device for the voltage-controlled semiconductor element of the present invention based on the embodiments, but these are only examples and are not limited to the above description.

[0078] The foregoing content merely illustrates the principles of the invention. Furthermore, those skilled in the art will be able to make numerous modifications and alterations; the invention is not limited to the precise configurations and applications shown and described above. All corresponding modifications and equivalents are considered to be within the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A driving device for a voltage-controlled semiconductor element, characterized in that, Driving voltage-controlled semiconductor devices, possessing: A driving circuit that drives the gate of the voltage-controlled semiconductor element; A gate resistor is disposed between the driving circuit and the gate of the voltage-controlled semiconductor element; A delay circuit that delays the drive signal output by the drive circuit for a predetermined time, the predetermined time being until the Miller effect occurs during the instantaneous change of the gate voltage. A single-trigger circuit outputs a pulse signal with a pulse width shorter than the Miller effect period, starting from the rising edge or falling edge of the delayed signal output by the delay circuit. A comparator that compares the gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor element, with a reference voltage equivalent to an overheat detection threshold voltage. as well as The circuit receives the pulse signal output by the single trigger circuit and the output signal of the comparator, and outputs an overheat detection signal if the gate voltage exceeds the reference voltage.

2. The driving device for a voltage-controlled semiconductor element as described in claim 1, characterized in that, The driving device for the voltage-controlled semiconductor element has an alarm output terminal, which notifies the outside of the overheat detection signal output by the circuit.

3. A driving device for a voltage-controlled semiconductor element, characterized in that, Driving voltage-controlled semiconductor devices, possessing: A driving circuit that drives the gate of the voltage-controlled semiconductor element; A gate resistor is disposed between the driving circuit and the gate of the voltage-controlled semiconductor element; A delay circuit that delays the drive signal output by the drive circuit for a predetermined time, the predetermined time being until the Miller effect occurs during the instantaneous change of the gate voltage. A single-trigger circuit outputs a pulse signal with a pulse width shorter than the Miller effect period, starting from the rising edge or falling edge of the delayed signal output by the delay circuit. as well as A sample-and-hold circuit acquires the gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor element, during the period of receiving the pulse signal, holds the gate voltage when the input of the pulse signal disappears, and outputs it.

4. The driving device for a voltage-controlled semiconductor element according to claim 3, characterized in that, The driving device for the voltage-controlled semiconductor element has a chip temperature output terminal, which transmits the signal output by the sample-and-hold circuit as a chip temperature detection signal to the outside.

5. A driving device for a voltage-controlled semiconductor element, characterized in that, Driving voltage-controlled semiconductor devices, possessing: A driving circuit that drives the gate of the voltage-controlled semiconductor element; A gate resistor is disposed between the driving circuit and the gate of the voltage-controlled semiconductor element; A delay circuit that delays the drive signal output by the drive circuit for a predetermined time, the predetermined time being until the Miller effect occurs during the instantaneous change of the gate voltage. A single-trigger circuit outputs a pulse signal with a pulse width shorter than the Miller effect period, starting from the rising edge or falling edge of the delayed signal output by the delay circuit. A comparator that compares the gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor element, with a reference voltage equivalent to an overheat detection threshold voltage. The circuit receives the pulse signal output by the single trigger circuit and the output signal of the comparator, and outputs an overheat detection signal if the gate voltage exceeds the reference voltage. as well as A sample-and-hold circuit acquires the gate voltage, which is temperature-dependent on the chip temperature of the voltage-controlled semiconductor element, during the period of receiving the pulse signal, holds the gate voltage when the input of the pulse signal disappears, and outputs it.

6. The driving device for a voltage-controlled semiconductor element according to claim 5, characterized in that, The driving device for the voltage-controlled semiconductor element includes: an alarm output terminal that notifies the outside of the overheat detection signal output by the circuit; and a chip temperature output terminal that notifies the outside of the signal output by the sample-and-hold circuit as a chip temperature detection signal.

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