JP5700095B2 - Power device control circuit and IPM using the same - Google Patents

Description

  The present invention relates to a power device control circuit for controlling a gate voltage of a power device and an IPM using the power device control circuit.

  When controlling a large current, a high breakdown voltage is required, and power devices such as IGBTs (Insulated Bipolar Transistors) and MOSFETs are often used. The power device is on / off controlled by voltage driving or current driving. The part that controls on / off of the power device is called a power device control circuit.

  The power device control circuit desirably controls the power device so as to reduce dv / dt and switching loss. Here, dv / dt is a time change amount of the gate voltage. As dv / dt increases, EMI noise (Electromagnetic Interference) increases. Since EMI noise interferes with control of electronic equipment, it must be suppressed. On the other hand, the switching loss is a power loss that occurs when the power device is turned on and off. Switching loss must be suppressed from the viewpoint of lower power consumption.

  For example, Patent Document 1 discloses a power device control circuit that speeds up dv / dt and reduces switching loss. The power device control circuit disclosed in Patent Document 1 detects a main circuit current and a gate voltage of a switching element (power device). Then, when the main circuit current is large, and the gate voltage reduces the gate resistance during the mirror period (paragraph 0014 of Patent Document 1). As a result, di / dt and dv / dt can be speeded up even when the switching element is driven with a large current, and the switching loss can be reduced. In Patent Document 1, the power device control circuit is expressed as a gate drive circuit or a drive circuit.

JP 2007-228447 A Japanese Patent Laid-Open No. 02-280675 JP-A-11-262243 JP 2000-232347 A Japanese Patent Laying-Open No. 2005-065029 JP 2006-324963 A JP 2008-029059 A JP 2008-182835 A JP 2008-092663 A

  In the case of a voltage-driven power device, the gate resistance is often increased in order to reduce dv / dt and suppress EMI. In the case of a current-driven power device, the drive current is often reduced. Here, the relationship between dv / dt and switching loss will be described with reference to FIG. FIG. 10 is a diagram for explaining the waveforms of IGBT Vg, Ic, Vce, and switching loss. In FIG. 10, the solid line is when dv / dt is large, and the broken line is when dv / dt is small. When dv / dt is increased, EMI noise increases, but switching ends in a short period. Therefore, the switching loss is small. On the other hand, when dv / dt is reduced, the mirror period is extended and switching is performed slowly. Therefore, the problem of EMI noise is suppressed, but the switching loss increases. That is, dv / dt reduction and switching loss reduction are in a trade-off relationship. Therefore, there is a problem that it is difficult to realize the reduction of EMI noise and the reduction of switching loss together.

  Incidentally, in the power device control circuit described in Patent Document 1, the gate voltage is used for control. More specifically, a gate voltage determination unit 52 is provided. Then, it is determined whether the gate voltage is a voltage in the mirror period. Here, the gate voltage of the power device is about 10 to 12 V and 15 V in the case of MOSFET and IGBT, respectively. However, the operating voltage of the power device control circuit is often several volts. Therefore, in order to control the gate voltage with the power device control circuit described in Patent Document 1, a level shift circuit is required. Therefore, the method described in Patent Document 1 has problems such as complicated control.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a power device control circuit capable of suppressing EMI noise and switching loss with a simple configuration, and an IPM using the power device control circuit.

A power device control circuit according to the invention of the present application is a power device control circuit that transmits a gate drive signal to a power device, the drive device having a plurality of drive elements connected to the gate of the power device, and the power device A conversion circuit that digitizes an analog value of the gate voltage of the power device and converts it into a digital value of the gate voltage, a threshold setting circuit that digitizes an actual threshold value of the power device having a certain variation and stores it as threshold digital data, A comparison circuit that compares the voltage digital value and the threshold digital data to switch the drive capability of the drive circuit, a temperature sensor that measures the temperature of the power device, and a digital that digitizes the temperature measured by the temperature sensor A temperature conversion circuit for converting the temperature value into a temperature value, and the threshold setting circuit includes the power device. A plurality of threshold digital data corresponding to the temperature of the memory is stored, and the comparison circuit selects threshold digital data corresponding to the digital temperature value from the plurality of threshold digital data and compares it with the gate voltage digital value. It is characterized by that.
Another power device control apparatus according to the invention of the present application is a power device control circuit that transmits a gate drive signal to a power device, the drive circuit having a plurality of drive elements connected to the gate of the power device, A conversion circuit that digitizes an analog value of the gate voltage of the power device and converts it to a digital value of the gate voltage; a threshold setting circuit that digitizes an actual threshold value of the power device having a certain variation and stores it as threshold digital data; A comparison circuit that switches the drive capability of the drive circuit by comparing the digital value of the gate voltage and the threshold digital data, a current detection element that measures the current flowing through the power device, and a measurement by the current detection element A current conversion circuit that digitizes the converted current and converts it into a digital current value, The threshold setting circuit stores a plurality of threshold digital data corresponding to the conduction current of the power device, and the comparison circuit selects the threshold digital data corresponding to the digital conduction current value from the plurality of threshold digital data. Is selected and compared with the digital value of the gate voltage.

  The IPM according to the invention of the present application is characterized in that the whole or a part of the power device control circuit described above is built in a control IC or a microcomputer.

  Another IPM according to the invention of the present application is characterized by including a diode made of SiC formed in a part of the power device and the power device control circuit described above.

  ADVANTAGE OF THE INVENTION According to this invention, the power device control circuit which suppressed EMI noise and switching loss, and IPM using the same can be manufactured by simple structure.

2 is a conceptual diagram illustrating a configuration of an IPM according to Embodiment 1. FIG. It is a flowchart explaining operation | movement of a power device control circuit. It is a figure explaining a gate waveform. It is a figure explaining the control which considered the temperature of the power device. It is a figure explaining the control which considered the flowing current of the power device. It is a drive circuit of Embodiment 2, and is a diagram for explaining a drive circuit including a resistance element. It is a figure explaining a drive circuit provided with MOSFET. FIG. 10 is a diagram illustrating a drive circuit according to a third embodiment, the drive circuit including two resistance elements. It is a figure explaining a drive circuit provided with 2 MOSFET. It is a figure explaining a subject.

Embodiment 1
This embodiment will be described with reference to FIGS. In some cases, the same material or the same and corresponding components are denoted by the same reference numerals, and description thereof is omitted a plurality of times. The same applies to other embodiments.

  FIG. 1 is a conceptual diagram of a power device control circuit of this embodiment and an IPM using the same. FIG. 1 shows a power device control circuit 10 and a power device 12. The power device control circuit 10 and the power device 12 may be collectively referred to as IPM. The power device control circuit 10 is a circuit that transmits a gate drive signal to the IGBT 26. On the other hand, the power device 12 includes an IGBT 26 and a diode 28. Hereinafter, the configuration of the power device control circuit 10 will be described.

  The power device control circuit 10 includes a conversion circuit 14. The conversion circuit 14 is connected to the gate wiring of the IGBT 26 and monitors the gate voltage. Further, the conversion circuit 14 converts the gate voltage from an analog value to a digital value. Hereinafter, the gate voltage converted into a digital value by the conversion circuit 14 is referred to as a “gate voltage digital value”.

  Further, the power device control circuit 10 includes a threshold setting circuit 18. The threshold setting circuit 18 includes a storage device and a reading circuit. In the storage device, the threshold value of the IGBT 26 is stored as digital data. For example, EPROM or Flash memory is used as the storage device. Hereinafter, the threshold digital data of the IGBT 26 stored in the threshold setting circuit 18 is referred to as “threshold digital data”.

  Further, the power device control circuit 10 includes a comparison circuit 16. The comparison circuit 16 is a portion that compares the gate voltage digital value and the threshold digital data to switch the drive capability of the drive circuit 20 described later. The comparison circuit 16 is connected to the conversion circuit 14 and the threshold setting circuit 18. The comparison circuit 16 is connected to the drive circuit 20 in order to switch the drive capability of the drive circuit 20. The operation of the comparison circuit 16 will be described later.

Further, the power device control circuit 10 includes a drive circuit 20. The drive circuit 20 has a plurality of drive elements 22. The plurality of drive elements 22 are connected in parallel to the gate of the IGBT 26. The drive capability of the drive circuit 20 is a control target of the comparison circuit 16. In other words, the number of drive elements to be used among the plurality of drive elements 22 is determined by the control from the comparison circuit 16.
The power device control circuit 10 of the present embodiment has the above-described configuration. Hereinafter, the operation of the power device control circuit 10 will be described with reference to FIG.

  FIG. 2 is a flowchart for explaining the operation of the power device control circuit 10 when the IGBT 26 is turned on. First, at step 50, the conversion circuit 14 acquires the value of the gate voltage of the IGBT 26. Acquisition of the value of the gate voltage is performed by wiring connecting the conversion circuit 14 and the gate wiring.

  Next, the process proceeds to step 52. In step 52, the conversion circuit 14 AD converts the gate voltage from an analog value to a digital value. Thereby, a gate voltage digital value is obtained. Here, the comparison circuit 16 is a low breakdown voltage control circuit such as a microcomputer. Therefore, the gate voltage of the IGBT 26, which is typically about 12V, cannot be input to the comparison circuit 16 as it is. Therefore, AD conversion is performed so that the gate voltage digital value becomes a voltage that can be handled by the comparison circuit 16.

  Next, the process proceeds to step 54. In step 54, the comparison circuit 16 compares the gate voltage digital value with the threshold digital data. Here, as described above, the comparison circuit 16 is a low breakdown voltage control circuit. However, since the gate voltage digital value and the threshold digital data are both digital signals, the comparison circuit can use them as they are. If the gate voltage digital value is lower than the threshold digital data, the process returns to step 50 again. On the other hand, when the gate voltage digital value is equal to or greater than the threshold digital data, the process proceeds to step 56. When the gate voltage digital value is lower than the threshold digital data, some of the plurality of drive elements 22 are unused.

  Step 56 will be described. In step 56, the comparison circuit 16 controls the drive circuit 20 so as to enhance the drive capability of the drive circuit 20. That is, in step 56, some of the unused drive elements among the plurality of drive elements 22 are turned on by the control of the comparison circuit 16. Thereby, the drive capability of the drive circuit 20 is increased, and the gate voltage dV / dt of the IGBT 26 is increased. In other words, at step 56, the switching speed of the IGBT 26 is accelerated. Here, the driving capability is improved by increasing the number of driving elements used. However, the driving capability may be increased by switching the driving element to be used.

  When the power device control circuit 10 is operated based on the flowchart of FIG. 2, a gate waveform as shown by the solid line in FIG. 3 is obtained. With reference to FIG. In FIG. 3, the section before the gate voltage digital value reaches the threshold digital data is section 1. In section 1, control is performed with dv / dt being small. This is a state where the drive capability of the drive circuit 20 is low. A section in which the gate voltage digital value is equivalent to the threshold digital data is section 2. Section 2 is a mirror period. As described above, in the section 2, the drive capability of the drive circuit 20 is increased. Therefore, the mirror period is shortened as compared with the case where the control is continued with the driving capability equivalent to that of the section 1. Here, the dashed-dotted waveform in FIG. 3 is a gate waveform when the IGBT is turned on while maintaining a constant driving capability.

A section in which the gate voltage digital value is higher than the threshold digital data is section 3. In the section 3, the state in which the drive capability of the drive circuit 20 is increased is maintained. Therefore, section 3 is a section having a higher dv / dt than section 1.
The operation of the power device control circuit 10 of this embodiment is as described above.

  If the power device control circuit 10 of this embodiment is used, EMI noise and switching loss can be suppressed. That is, EMI noise is suppressed in order to maintain a low dv / dt state when the gate voltage digital value is lower than the threshold digital data. On the other hand, when the gate voltage digital value is equal to or greater than the threshold digital data, the drive capability of the drive circuit 20 is enhanced. Therefore, since the mirror period is shortened and the subsequent switching is accelerated, the switching loss is suppressed. Thus, according to the configuration of the power device control circuit 10 of the present embodiment, the gate waveform of the IGBT 26 can be optimized.

  If the power device control circuit 10 of this embodiment is used, EMI noise and switching loss can be easily suppressed with a simple configuration. In the present embodiment, both the gate voltage digital value and the threshold digital data used by the comparison circuit 16 are digitized. Therefore, the gate voltage of the IGBT 26 can be used for controlling the drive circuit 20 without using a level shift circuit or the like. Therefore, EMI noise and switching loss can be easily suppressed with a simple configuration. The gate voltage digital value generated by the conversion circuit 14 can also be applied to other controls. Therefore, it is superior in terms of controllability and applicability as compared with the case where the gate voltage value is used as it is.

  If the power device control circuit 10 of the present embodiment is used, the threshold value can be finely adjusted. That is, the number of adjustment bits of the threshold digital data is increased. Then, the threshold digital data is finely adjusted so as to match the actual threshold. For example, the fine adjustment is performed so that an actual threshold value having a certain variation due to manufacturing variation or the like matches the threshold digital data. Thereby, highly accurate control can be performed. Such fine adjustment is possible because threshold information (threshold digital data) is digitized.

  If the power device control circuit 10 of the present embodiment is used, a plurality of power devices can be controlled by a single power device control circuit. In this case, the power device control circuit stores threshold digital data for each power device having various thresholds. Then, a gate voltage digital value is generated for each power device having various threshold values. In this way, it is possible to control a plurality of power devices with one power device control circuit.

  If the power device control circuit 10 of the present embodiment is used, verification (test) of the power device control circuit or the IPM can be facilitated. The threshold setting circuit 18 of the present embodiment stores threshold digital data obtained by digitizing the threshold data of the IGBT 26. Therefore, it is possible to verify (test) the power device control circuit or the IPM without the need to change the circuit components by changing parts.

Hereinafter, modifications of the present embodiment will be described.
For example, when the power device control circuit 100 shown in FIG. 4 is used, the effect of the present invention can be enhanced. The power device control circuit 100 shown in FIG. 4 is characterized in that the temperature of the power device 12 is reflected in the control of the drive circuit 20. As shown in FIG. 4, an on-chip diode 114 is mounted on a chip constituting the power device 12. The temperature of the power device 12 is measured by the on-chip diode 114. The measured temperature is converted into a digital temperature value by the temperature conversion circuit 112. The temperature level threshold setting circuit 110 stores the temperature level threshold. The temperature level threshold setting circuit 110 is arranged in the threshold setting part 106 together with the threshold setting circuit 18. The power device control circuit 100 further includes a temperature comparison circuit 104 that compares the digital temperature value with the temperature level threshold.

  In the configuration of FIG. 4, digitization processing of the gate voltage is also performed, but the description thereof is omitted here. However, the threshold setting circuit 18 stores threshold digital data when the temperature of the power device is high (high-temperature threshold digital data) and threshold digital data when the power device is low (low-temperature threshold digital data). That is, it is assumed that the threshold setting circuit 18 stores two types of threshold digital data.

  In the temperature comparison circuit 104, the digital temperature value and the temperature level threshold are compared, and the comparison result is reflected in the control of the drive circuit 20. Specifically, one of the two types of threshold digital data stored in the threshold setting circuit 18 is selected based on the comparison result of the temperature comparison circuit 104. When the digital temperature value is higher than the temperature level threshold, high temperature threshold digital data is used. When the digital temperature value is lower than the temperature level threshold value, low-temperature threshold digital data is used. Therefore, the threshold digital data used in the comparison circuit 16 is determined by the temperature of the power device 12. It is known that the threshold voltage of the IGBT 26 varies depending on the temperature of the power device. Therefore, the drive circuit 20 can be controlled with high accuracy by using appropriate threshold digital data according to the temperature of the power device as described above. Therefore, it is possible to control the drive circuit 20 suitable for the operating environment of the power device.

  The threshold setting circuit 18 may store three or more types of threshold digital data instead of two types of threshold digital data. Further, a configuration in which the digital temperature value is directly transmitted to the threshold setting circuit 18 or the comparison circuit 16 without performing the comparison by the temperature comparison circuit is also conceivable. Further, instead of the on-chip diode 114, another temperature sensor such as a thermistor may be used.

Another modification will be described with reference to FIG.
For example, when the power device control circuit 200 shown in FIG. 5 is used, the effect of the present invention can be enhanced. The power device control circuit 200 shown in FIG. 5 is characterized in that the current flowing through the IGBT 26 is reflected in the control of the drive circuit 20. As shown in FIG. 5, a shunt resistor 208 is disposed in the power device control circuit 200. Both ends of the shunt resistor 208 are connected to the IGBT 26 so that the collector current of the IGBT 26 can be detected. The conduction current detected by the shunt resistor 208 is converted into a digital conduction current value by the conduction current conversion circuit 206. The current level threshold setting circuit 204 stores a current level threshold. The current level threshold setting circuit 204 is arranged in the threshold setting part 202 together with the threshold setting circuit 18. The power device control circuit 200 further includes a conduction current comparison circuit 220 that compares the digital conduction current value with a current level threshold value.

  In the configuration of FIG. 5, digitization processing of the gate voltage is also performed. However, the threshold setting circuit 18 includes threshold digital data when the power device current is high (threshold digital data for high current) and threshold digital data when the power device current is low (for low current). Threshold digital data) is stored. That is, it is assumed that the threshold setting circuit 18 stores two types of threshold digital data.

  In the conduction current comparison circuit 220, the digital conduction current value is compared with the current level threshold value, and the comparison result is reflected in the control of the drive circuit 20. Specifically, one of the two types of threshold digital data stored in the threshold setting circuit 18 is selected based on the comparison result of the conduction current comparison circuit 220. When the digital current value is higher than the current level threshold value, high current threshold digital data is used. When the digital flow current value is lower than the current level threshold value, low flow current threshold digital data is used. Therefore, the threshold digital data transmitted from the threshold setting circuit 18 to the comparison circuit 16 is determined by the flowing current of the power device 12. The drive circuit 20 can be controlled with high accuracy by using the value of the digital conduction current to select the threshold digital data. Therefore, it is possible to control the drive circuit 20 suitable for the operating environment of the power device.

  The threshold setting circuit 18 may store three or more types of threshold digital data instead of two types of threshold digital data. Further, a current detection element such as a current sense formed on the chip of the current transformer or the power device 12 may be used instead of the shunt resistor 208.

Another modification will be described.
The whole or a part of the power device control circuit 10 may be built in a control IC or a microcomputer. As a result, it is possible to reduce the number of mounted parts and circuit components rather than the discrete parts. Therefore, the cost can be reduced and the defect rate can also be reduced.

Another modification will be described.
The diode 28 described in FIG. 1 and the like may be manufactured using SiC as a material. Since SiC has a high voltage resistance, the current density can be increased. Therefore, since the diode can be reduced in size, the IPM can be reduced in size.

Another modification will be described.
The IGBT 26 and the diode 28 constituting the power device 12 may be manufactured using SiC as a material. The IPM can be reduced in size as described above. Further, when the power device includes a bipolar transistor or a MOSFET, the same applies even if they are made of SiC.

Another modification will be described.
The power device 12 may be composed of an RC (Reverse-Conductive) -IGBT manufactured using SiC as a material. In this case, since SiC is used, the IPM can be reduced in size as described above. Further, it is not necessary to connect a diode in reverse parallel to the IGBT, and the assembly of the IPM can be facilitated.

  In addition, for example, the power device 12 may have a MOSFET instead of the IGBT 26. The gate voltage of the MOSFET is about 10-12V. If such a high voltage is converted into a digital value having a low voltage that can be processed by the comparison circuit, the effect of the present invention can be obtained.

Embodiment 2
This embodiment will be described with reference to FIGS. The present embodiment relates to a configuration of a drive circuit controlled by a comparison circuit. Since the input to the comparison circuit is the same as that of the first embodiment, a description thereof will be omitted. As shown in FIG. 6, the drive circuit 302 of this embodiment includes a plurality of resistance elements as the plurality of drive elements 304. Each resistance element has the same resistance value. The plurality of resistance elements are arranged in parallel. Then, except for one resistance element, it is connected to the comparison circuit 16, and ON / OFF control is performed from the comparison circuit 16.

  In the present embodiment, gate driving is performed only with a resistor not connected to the comparison circuit 16 in a section where the gate voltage digital value is less than the threshold digital data. Therefore, the driving capability is low in this section, and the value of dv / dt is small. When the gate voltage digital value is equal to or greater than the threshold digital data, some of the resistance elements are connected to the power source. Therefore, the driving capability is high in this section, and the value of dv / dt is large.

  As a result, a gate waveform as shown by the solid line in FIG. 3 is obtained. Therefore, the same effect as Embodiment 1 can be acquired. In particular, since the plurality of driving elements 304 are composed of resistance elements having the same resistance value, the following two points are excellent. The first point is that if one characteristic of the plurality of driving elements 304 is grasped, the characteristic and variation in the case of parallel use can be grasped. The second point is that the threshold variation can be adjusted. That is, the on / off state of the resistance element can be controlled to meet the actual threshold value.

  In the present embodiment, a plurality of driving elements are configured by resistance elements, but the present invention is not limited to this. For example, a MOSFET may be used instead of the resistance element. A configuration using a plurality of MOSFETs as a plurality of driving elements will be described with reference to FIG. The power device control circuit 400 includes a drive circuit 402. The drive circuit 402 includes a MOSFET 410 and a MOSFET 412. MOSFET 410 and MOSFET 412 have the same characteristics. Further, the MOSFET 410 and the MOSFET 412 are arranged in parallel. MOSFET 410 and MOSFET 412 are connected to first drive circuit 404 and second drive circuit 406, respectively. The first drive circuit 404 and the second drive circuit 406 are connected to the comparison circuit 16.

  In a section where the gate voltage digital value is less than the threshold digital data, gate driving is performed only by the MOSFET 410. Therefore, the driving capability is low in this section, and the value of dv / dt is small. When the gate voltage digital value is equal to or greater than the threshold digital data, the MOSFET 412 is used in addition to the MOSFET 410. Therefore, the driving capability is high in this section, and the value of dv / dt is large. Therefore, the same effect as when a plurality of resistance elements are used can be obtained.

  By the way, if the configuration using resistors as in the configuration of FIG. 6 is made into an IC, the area of the power device control circuit can be reduced compared to the case where MOSFETs are used. Therefore, the cost can be reduced.

  Note that the number of resistance elements and the number of MOSFETs are appropriately determined from the viewpoint of driving capability. In addition, modifications corresponding to the first embodiment can be made.

Embodiment 3
This embodiment will be described with reference to FIGS. The present embodiment relates to a configuration of a drive circuit controlled by a comparison circuit. Since the input to the comparison circuit is the same as that of the first embodiment, a description thereof will be omitted. As shown in FIG. 8, the drive circuit 502 of this embodiment includes a resistor 504 and a resistor 506. The resistor 504 has a lower resistance value than the resistor 506. Further, the resistor 504 and the resistor 506 are arranged in parallel. The resistors 504 and 506 are both connected to the comparison circuit 16 and are controlled to be turned on / off by the comparison circuit 16.

  In the present embodiment, the gate drive is performed only by the resistor 506 in the section where the gate voltage digital value is less than the threshold digital data. Therefore, the driving capability is low in this section, and the value of dv / dt is small. When the gate voltage digital value is equal to or greater than the threshold digital data, gate driving is performed only by the resistor 504. Therefore, the driving capability is high in this section, and the value of dv / dt is large.

  As a result, a gate waveform as shown by the solid line in FIG. 3 is obtained. Therefore, the same effect as Embodiment 1 can be acquired. In particular, since the drive circuit 502 includes a plurality of resistance elements having different resistance values, the following three points are excellent. The first point is that the number of drive elements can be reduced to a minimum of two elements. That is, the two elements of the resistor for use in section 1 and the resistor for use in sections 2 and 3 shown in FIG. Therefore, the power device control circuit 500 can be reduced in size. The second point is that the cost can be reduced and the defective rate can be reduced because the number of parts is reduced. The third point is that the drive circuit 502 can be miniaturized by making it an IC.

  In the present embodiment, the driving element is configured by the two resistance elements, but the present invention is not limited to this. For example, a MOSFET may be used instead of the resistance element. A configuration using two MOSFETs as drive elements will be described with reference to FIG. The power device control circuit 600 includes a drive circuit 602. The drive circuit 602 includes a MOSFET 604 and a MOSFET 606. MOSFET 604 has a larger current capacity than MOSFET 606. Further, the MOSFET 604 and the MOSFET 606 are arranged in parallel. MOSFET 604 and MOSFET 606 are connected to first drive circuit 610 and second drive circuit 612, respectively. The first drive circuit 610 and the second drive circuit 612 are connected to the comparison circuit 16.

  In a section where the gate voltage digital value is less than the threshold digital data, gate driving is performed only by the MOSFET 606. Therefore, the driving capability is low in this section, and the value of dv / dt is small. When the gate voltage digital value is equal to or greater than the threshold digital data, the MOSFET 604 is used. Therefore, the driving capability is high in this section, and the value of dv / dt is large. Therefore, it is possible to obtain the same effect as when the above-described resistance element 2 is used. Note that the number of resistance elements and the number of MOSFETs are appropriately determined from the viewpoint of driving capability. In addition, modifications corresponding to the first embodiment can be made.

  DESCRIPTION OF SYMBOLS 10 Power device control circuit, 12 Power device, 14 Conversion circuit, 16 Comparison circuit, 18 Threshold setting circuit, 20 Drive circuit, 22 Multiple drive elements, 26 IGBT, 28 Diode

Claims (6)

A power device control circuit for transmitting a gate drive signal to a power device,
A drive circuit having a plurality of drive elements connected to the gate of the power device;
A conversion circuit that digitizes an analog value of the gate voltage of the power device and converts it to a digital value of the gate voltage;
A threshold setting circuit that digitizes an actual threshold value of the power device having a certain variation and stores it as threshold digital data;
A comparison circuit that compares the gate voltage digital value and the threshold digital data to switch the drive capability of the drive circuit ;
A temperature sensor for measuring the temperature of the power device;
A temperature conversion circuit that digitizes the temperature measured by the temperature sensor and converts it into a digital temperature value;
The threshold setting circuit stores a plurality of threshold digital data corresponding to the temperature of the power device,
The comparison circuit selects threshold value digital data corresponding to the digital temperature value from the plurality of threshold value digital data, and compares it with the gate voltage digital value. A power device control circuit for transmitting a gate drive signal to a power device,
A drive circuit having a plurality of drive elements connected to the gate of the power device;
A conversion circuit that digitizes an analog value of the gate voltage of the power device and converts it to a digital value of the gate voltage;
A threshold setting circuit that digitizes an actual threshold value of the power device having a certain variation and stores it as threshold digital data;
A comparison circuit that compares the gate voltage digital value and the threshold digital data to switch the drive capability of the drive circuit ;
A current detection element for measuring a current flowing through the power device;
A conduction current conversion circuit that digitizes the conduction current measured by the current detection element and converts it into a digital conduction current value;
The threshold setting circuit stores a plurality of threshold digital data corresponding to the current flowing through the power device,
The comparison circuit selects threshold digital data corresponding to the digital conduction current value from the plurality of threshold digital data, and compares the digital digital value with the gate voltage digital value.   An IPM characterized in that the power device control circuit according to claim 1 or 2 is entirely or partially incorporated in a control IC or a microcomputer.   The power device control circuit according to claim 1 or 2,
  A power device connected to the power device control circuit and receiving a gate drive signal;
  An IPM comprising: a diode made of SiC formed in a part of the power device.   The IPM according to claim 3 or 4, wherein the element constituting the power device is made of SiC.   The IPM according to claim 3, wherein the power device is an RC-IGBT.

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