JP5533555B2 - Electronic equipment - Google Patents

Description

  The present invention relates to an electronic device including a switching element and a drive circuit.

  Conventionally, as an electronic device including a switching element and a drive circuit, for example, there is a power converter disclosed in Patent Document 1.

  This power converter includes an IGBT, three MOSFETs, and a control circuit. The source of the first MOSFET is connected to the drive circuit power supply, the drain is connected to the gate of the IGBT, and the gate is connected to the control circuit. The sources of the second and third MOSFETs are connected to the emitter of the IGBT, the drain is connected to the gate of the IGBT, and the gate is connected to the control circuit.

  The control circuit drives the IGBT by controlling the three MOSFETs based on a drive signal input from the outside. When the drive signal instructs to turn on the IGBT, the control circuit turns on the first MOSFET and turns off the second MOSFET. As a result, charges are charged from the drive circuit power supply to the gate of the IGBT. As a result, the gate voltage becomes higher than the on / off threshold voltage, and the IGBT is turned on.

  On the other hand, when the drive signal instructs to turn off the IGBT, the control circuit turns off the first MOSFET and turns on the second MOSFET. As a result, charges are discharged from the gate of the IGBT. As a result, the gate voltage becomes lower than the on / off threshold voltage, and the IGBT is turned off. Then, when the gate voltage becomes a predetermined value or less, the control circuit turns on the third MOSFET. As a result, the electric charge is further discharged from the gate of the IGBT, and the off state of the IGBT is maintained.

Japanese Patent No. 3430878

  By the way, in the power converter described above, when the second MOSFET is turned on when the first MOSFET is turned on or malfunctioned, the gate voltage of the IGBT is not lowered, and an abnormal state in which the IGBT cannot be turned off occurs. To do. At this time, if the gate voltage of the IGBT is a voltage within a predetermined range near the ON / OFF threshold voltage, the collector-emitter voltage, that is, the ON voltage increases, and the heat generation of the IGBT increases. If such an abnormal state continues, there is a possibility that the IGBT generates heat and is thermally destroyed.

  The present invention has been made in view of such circumstances, and even if the on-drive switching element corresponding to the first MOSFET enters an abnormal state in which the switching element cannot be turned off due to an on failure or the like, An object of the present invention is to provide an electronic device capable of preventing destruction.

  Therefore, as a result of intensive research and trial and error to solve this problem, the present inventors turn off the switching element other than the off-drive switching element based on the drive signal and the current flowing through the on-drive switching element. Thus, the present inventors have found that the thermal destruction of the switching element can be prevented even when the on-drive switching element is in an abnormal state where the switching element cannot be turned off due to an on failure or the like, and the present invention has been completed.

That is, the electronic device according to claim 1 includes a first switching element that is driven by controlling a voltage of a control terminal, a driving power supply circuit that supplies a voltage for driving the first switching element, and one end Is connected to the output terminal of the driving power supply circuit, the other end is connected to the control terminal of the first switching element, and the ON driving switching element that charges the control terminal of the first switching element by being turned on The switching element for off driving connected to the control terminal of the first switching element and discharging the charge from the control terminal of the first switching element by turning on, and the switching element for on driving based on the input drive signal and off By controlling the driving switching element, the voltage of the control terminal of the first switching element is controlled to drive the first switching element. An electronic device comprising: a control circuit having a cutoff switching element that is connected to a control terminal of the first switching element and discharges electric charge from the control terminal of the first switching element when turned on; When an abnormal current flows through the first switching element, the cutoff switching element is controlled to turn off the first switching element, and the drive signal is turned on even though the drive signal indicates that the first switching element is turned off. When a current flows through the switching element, the first switching element is determined to be in an abnormal state, and the cutoff switching element is controlled to turn off the first switching element. According to this configuration, when the first switching element is in an abnormal state, the first switching element is turned off by controlling the blocking switching element and discharging the charge from the control terminal of the first switching element. Therefore, it is possible to prevent thermal destruction of the first switching element.

In the electronic device according to claim 2 , the other end of the on-drive switching element is connected to the control terminal of the first switching element via the on-drive resistor, and the control circuit is connected to the voltage of the on-drive resistor. Based on this, it is determined whether or not a current is flowing through the ON drive switching element. According to this configuration, it is possible to reliably determine whether or not a current flows through the on-drive switching element without newly providing a current detection resistor.

In the electronic device according to claim 3 , one end of the on-drive switching element is connected to the output terminal of the drive power supply circuit via the current detection resistor, and the control circuit is based on the voltage of the current detection resistor. It is characterized in that it is determined whether or not a current flows through the on-drive switching element. According to this configuration, it is possible to reliably determine whether or not a current is flowing through the on-drive switching element by using the current detection resistor provided between the drive power supply circuit and the on-drive switching element.

In the electronic device according to claim 4 , the drive power supply circuit has an input terminal connected to the power supply circuit via a current detection resistor, converts the voltage of the power supply circuit, and drives the first switching element. And the control circuit determines whether or not current is flowing through the on-drive switching element based on the voltage of the current detection resistor. According to this configuration, when a current flows from the driving power supply circuit to the on-driving switching element, a current also flows from the power supply circuit to the driving power supply circuit. Therefore, it is possible to reliably determine whether or not current is flowing through the on-drive switching element by using a current detection resistor provided between the power supply circuit and the drive power supply circuit.

The electronic device according to claim 5 is characterized in that the control circuit determines whether or not a current flows through the on-drive switching element based on the voltage of the drive power supply circuit. According to this configuration, when a current flows from the drive power supply circuit to the on-drive switching element, the voltage of the drive power supply circuit decreases. Therefore, it is possible to reliably determine whether or not a current is flowing through the on-drive switching element based on the voltage of the drive power supply circuit.

In the electronic device according to claim 6 , the resistance value of the on-drive resistor is set in consideration of the magnitude of the current required when charging the control terminal of the first switching element. It is characterized by. According to this configuration, it is possible to suppress and set the resistance value while securing a current necessary for charging the control terminal of the first switching element. Therefore, the loss of the on-drive resistance can be suppressed.

The electronic device according to claim 7 is characterized in that the current required when charging the control terminal of the first switching element takes into account the ambient temperature of the first switching element during operation. And According to this configuration, the current required for charging the control terminal of the first switching element varies depending on the ambient temperature during operation. However, even in such a case, the resistance value can be set while suppressing the current while securing the current necessary for charging the control terminal of the first switching element. Therefore, loss of the current detection resistor can be suppressed.

In the electronic device according to claim 8 , the resistance value of the current detection resistor is set in consideration of the magnitude of the current required when charging the control terminal of the first switching element. It is characterized by. According to this configuration, the resistance value can be suppressed and set while securing a current necessary for charging the control terminal of the first switching element. Therefore, loss due to the current detection resistor can be suppressed.

The electronic device according to claim 9 is characterized in that the current required for charging the control terminal of the first switching element takes into account the ambient temperature of the first switching element during operation. And According to this configuration, the current required for charging the control terminal of the first switching element varies depending on the ambient temperature during operation. However, even in such a case, the resistance value can be set while suppressing the current while securing the current necessary for charging the control terminal of the first switching element. Therefore, loss of the current detection resistor can be suppressed.

The electronic device according to claim 1 0, is driven by controlling the voltage of the control terminal, a second switching element connected in series to the first switching element, second switching element based on the drive signal inputted And a drive circuit for driving the second switching element by controlling the voltage of the control terminal and turning off the second switching element when an abnormal current is flowing through the second switching element. When it is determined that the first switching element is in an abnormal state, the first switching element is turned on. According to this configuration, when the first switching element is in an abnormal state and is turned on, when the second switching element is turned on, both the first and second switching elements are turned on, and the first and second switching elements are turned on. An abnormal current flows in When an abnormal current flows through the second switching element, the drive circuit turns off the second switching element. Therefore, the abnormal current flowing through the first switching element can be interrupted. Therefore, it is possible to prevent thermal destruction of the first switching element.

The electronic device of claim 1 1, a first switching element which is driven by controlling the voltage of the control terminal, and a power supply circuit for driving supplies a voltage for driving the first switching element, one end Is connected to the output terminal of the driving power supply circuit, and the other end is connected to the control terminal of the first switching element, and when turned on, the control terminal of the first switching element is charged with an electric charge. A switching element connected to a control terminal of the first switching element and turned on to discharge electric charges from the control terminal of the first switching element; and the on-state based on an input drive signal The voltage of the control terminal of the first switching element is controlled by controlling the driving switching element and the off-driving switching element. And a control circuit for driving the first switching element, and a second switching element that is driven by controlling the voltage of the control terminal and connected in series to the first switching element. The second switching element is driven by controlling the voltage of the control terminal of the second switching element based on the drive signal to be driven, and when the abnormal current flows through the second switching element, the second switching element is A drive circuit that turns off, and the control circuit, when a drive signal indicates that the first switching element is turned off, when a current flows through the on-drive switching element, It is determined that the first switching element is in an abnormal state, and the first switching element is turned on. According to this configuration, when the first switching element is in an abnormal state and is turned on, when the second switching element is turned on, both the first and second switching elements are turned on, and the first and second switching elements are turned on. An abnormal current flows in When an abnormal current flows through the second switching element, the drive circuit turns off the second switching element. Therefore, the abnormal current flowing through the first switching element can be interrupted. Therefore, it is possible to prevent thermal destruction of the first switching element.

The electronic device according to claim 12 is characterized in that the control circuit outputs an abnormal signal to the outside when it is determined that the first switching element is in an abnormal state. According to this configuration, the abnormal state of the first switching element can be notified to the outside.
The electronic device according to claim 1 3, control circuit, even though the drive signal indicates the ON of the first switching element, the predetermined time has elapsed for charging the charge to the control terminal of the first switching element When the current flows through the on-drive switching element, it is determined that the first switching element is in an abnormal state.

  According to this configuration, when the drive signal instructs to turn on the first switching element, the control circuit turns off the off-drive switching element and turns on the on-drive switching element. Thereby, the first switching element is turned on. However, when the off-drive switching element is turned on due to an on-failure or malfunction, a current that does not flow in a normal state despite the elapse of a predetermined time for charging the control terminal of the first switching element. It flows to the switching element for on drive. And the voltage of the control terminal of a 1st switching element does not fully rise, but the abnormal state which cannot turn on a 1st switching element generate | occur | produces. At this time, if the voltage of the control terminal is a voltage within a predetermined range near the on / off threshold voltage, the on-voltage increases and the heat generation of the first switching element increases. If such an abnormal state continues, the first switching element may generate heat and be thermally destroyed. However, the control circuit indicates that the drive signal indicates that the first switching element is turned on, and a current is supplied to the on-drive switching element even though a predetermined time has elapsed for charging the control terminal of the first switching element. When it is flowing, it is determined that the first switching element is in an abnormal state. Then, the first switching element other than the off-drive switching element is turned off. Therefore, even when the off-drive switching element is in an abnormal state in which the first switching element cannot be turned on due to an on failure or the like, it is possible to prevent thermal destruction of the first switching element.

  Note that the first and second switching elements and the switching elements are introduced for the sake of convenience.

It is a circuit diagram of the motor control device in a 1st embodiment. It is a circuit diagram of the control apparatus in FIG. It is a timing chart of the drive signal in the normal state, the on-drive FET and the off-drive FET, the current flowing through each FET, and the gate voltage waveform of the IGBT. FIG. 5 is a timing chart of a drive signal, an on-drive FET, and an off-drive FET when the on-drive FET is turned on, and a current flowing through each FET and a gate voltage waveform of the IGBT. FIG. 6 is a timing chart of a drive signal, an on-drive FET, and an off-drive FET when the off-drive FET is turned on, and a current flowing through each FET and an IGBT gate voltage waveform. It is a circuit diagram of the control apparatus in 2nd Embodiment. It is a circuit diagram of the control apparatus in another form which changed the connection position of resistance for current detection to a 2nd embodiment. It is a circuit diagram of the control device in another form which abolished resistance for current detection to a 2nd embodiment. It is a circuit diagram of the control apparatus in 3rd Embodiment. It is a circuit diagram of the control apparatus in 4th Embodiment.

  Next, an embodiment is given and this invention is demonstrated in detail. In the present embodiment, an example in which the electronic device according to the present invention is applied to a motor control device that is mounted on a vehicle and controls a motor for driving the vehicle is shown.

(First embodiment)
First, the configuration of the motor control device of the first embodiment will be described with reference to FIG. Here, FIG. 1 is a circuit diagram of the motor control device according to the first embodiment.

  The motor control device 1 (electronic device) shown in FIG. 1 converts a DC high voltage (for example, 288V) output from a high voltage battery B1 insulated from the vehicle body into a three-phase AC voltage and supplies it to the vehicle drive motor M1. This is a device for controlling the vehicle drive motor M1. The motor control device 1 includes a smoothing capacitor 10, an inverter device 11, and a control device 12.

  The smoothing capacitor 10 is an element for smoothing the DC high voltage of the high voltage battery B1. One end of the smoothing capacitor 10 is connected to the positive terminal of the high voltage battery B1. The other end is connected to the negative terminal of the high voltage battery B1. Furthermore, the negative terminal of the high voltage battery B1 is connected to the ground for the high voltage battery insulated from the vehicle body.

  The inverter device 11 is a device that converts the DC voltage smoothed by the smoothing capacitor 10 into a three-phase AC voltage and supplies it to the vehicle drive motor M1. The inverter device 11 includes IGBTs 110a to 110f and current sense resistors 111a to 111f.

  The IGBTs 110a to 110f are switching elements that are driven by controlling the voltage of the gate (control terminal) and convert the DC voltage smoothed by the smoothing capacitor 10 by turning on and off to a three-phase AC voltage. . The IGBTs 110a to 110f include a current sense terminal through which a current that is proportional to the collector current and smaller than the collector current flows. The IGBTs 110a (second switching elements) and 110d (first switching elements), the IGBTs 110b and 110e, and the IGBTs 110c and 110f are respectively connected in series. Specifically, the emitters of the IGBTs 110a to 110c are connected to the collectors of the IGBTs 110d to 110f, respectively. Three sets of IGBTs 110a and 110d, IGBTs 110b and 110e, and IGBTs 110c and 110f connected in series are connected in parallel. The collectors of the IGBTs 110 a to 110 c are connected to one end of the smoothing capacitor 10, and the emitters of the IGBTs 110 d to 110 f are connected to the other end of the smoothing capacitor 10. The gates and emitters of the IGBTs 110a to 110f are connected to the control device 12, respectively. Further, the series connection points of the IGBTs 110a and 110d, the IGBTs 110b and 110e, and the IGBTs 110c and 110f that are connected in series are respectively connected to the vehicle drive motor M1.

  The current sense resistors 111a to 111f are elements for converting the current flowing through the IGBTs 110a to 110f into a voltage. Specifically, it is an element that converts a current flowing through a current sense terminal into a voltage. One ends of the current sense resistors 111a to 111f are connected to the current sense terminals of the IGBTs 110a to 110f, and the other ends are connected to the emitters of the IGBTs 110a to 110f, respectively. Further, both ends of the current sense resistors 111a to 111f are connected to the control device 12, respectively.

  The control device 12 is a device that controls the IGBTs 110a to 110f. The control device 12 is connected to the gates and emitters of the IGBTs 110a to 110f, respectively. Moreover, in order to detect the electric current which flows into IGBT110a-110f, it connects to the both ends of current sense resistance 111a-111f, respectively.

  Next, the control device will be described in detail with reference to FIG. Here, FIG. 2 is a circuit diagram of the control device in FIG. Specifically, it is a circuit diagram showing a circuit portion for one IGBT.

  As shown in FIG. 2, the control device 12 has a driving power supply circuit 120, an on driving circuit 121, an off driving circuit 122, an off holding circuit 123, and a blocking circuit 124, with respect to the IGBT 110 d. The overcurrent detection circuit 126, the short circuit detection circuit 127, and the control circuit 128 are provided. In the same manner, the control device 12 also applies to the other IGBTs 110a to 110c, 110e, and 110f, a driving power supply circuit, an on-driving circuit, an off-driving circuit, an off-holding circuit, and a shut-off circuit. An overcurrent detection circuit, a short circuit detection circuit, and a control circuit.

  The drive power supply circuit 120 is a circuit that supplies a voltage for driving the IGBT 110d. The drive power supply circuit 120 converts the voltage supplied from the power supply circuit (not shown) into a stabilized voltage and outputs the voltage. Further, the operation is stopped based on an instruction from the control circuit 128. The input terminal of the driving power supply circuit 120 is connected to the power supply circuit. The positive terminal is connected to the ON drive circuit 121. Further, the negative terminal is connected to the ground for the high voltage battery insulated from the vehicle body, and is connected to the emitter of the IGBT 110d via the ground for the high voltage battery. In addition, the control terminal is connected to the control circuit 128.

  The on drive circuit 121 is a circuit for turning on the IGBT 110d. Specifically, this is a circuit that charges the gate of the IGBT 110d, sets the gate voltage higher than a threshold voltage for turning on and off, and turns on the IGBT 110d. The on drive circuit 121 includes an on drive FET 121a (on drive switching element) and an on drive resistor 121b.

  The on-drive FET 121a is a switching element that charges the gate of the IGBT when turned on. Specifically, it is a P-channel MOSFET. The source of the on-drive FET 121 a is connected to the positive terminal of the drive power supply circuit 120. The drain is connected to the gate of the IGBT 110d through the on-drive resistor 121b. Further, the gate is connected to the control circuit 128.

  The off drive circuit 122 is a circuit for turning off the IGBT 110d. Specifically, this is a circuit that discharges electric charges from the gate of the IGBT 110d, lowers the gate voltage below a threshold voltage for turning on and off, and turns off the IGBT 110d. The off drive circuit 122 includes an off drive FET 122a (off drive switching element) and an off drive resistor 122b.

  The off-drive FET 122a is a switching element that discharges charges from the gate of the IGBT 110d when turned on. Specifically, it is an N-channel MOSFET. The source of the off drive FET 122a is connected to the ground for the high voltage battery insulated from the vehicle body, and is connected to the negative terminal of the drive power supply circuit 120 and the emitter of the IGBT 110d via the ground for the high voltage battery. The drain is connected to the gate of the IGBT 110d through the off-drive resistor 122b. Further, the gate is connected to the control circuit 128.

  The off-holding circuit 123 is a circuit that holds the off state of the IGBT 110d. Specifically, when the gate voltage of the IGBT 110d falls below an off-holding threshold value that is lower than the on / off threshold voltage, the gate voltage is quickly turned on / off by discharging charges from the gate of the IGBT 110d more quickly than the off drive circuit 122. This is a circuit that keeps the IGBT 110d in an OFF state by lowering the threshold voltage. The off holding circuit 123 includes an off holding FET 123a (off holding switching element) and a gate resistor 123b.

  The off-holding FET 123a is a switching element that discharges charges from the gate of the IGBT 110d when turned on. Specifically, it is an N-channel MOSFET. The source of the off-holding FET 123a is connected to the ground for the high voltage battery insulated from the vehicle body, and is connected to the negative terminal of the driving power supply circuit 120 and the emitter of the IGBT 110d via the ground for the high voltage battery. The drain is connected to the gate of the IGBT 110d. Furthermore, the gate is connected to the control circuit 128 via the gate resistor 123b.

  Here, the resistance value of the on-drive resistor 121b is set in consideration of the amount of current required when charging the gate of the IGBT 110d. The current required for charging the gate of the IGBT 110d is a value that takes into account the ambient temperature of the IGBT 110d during operation. Further, the resistance value of the off-drive resistor 122b is set in consideration of the amount of current required when discharging the charge from the gate of the IGBT 110d. Note that the current required for discharging the charge from the gate of the IGBT 110d is a value that takes into account the ambient temperature of the IGBT 110d during operation. That is, the resistance value is set according to the current capacity of the IGBT 110d in consideration of the ambient temperature of the IGBT 110d during operation.

  The cutoff circuit 124 is a circuit that turns off the IGBT 110d in place of the off-drive circuit 122 when an abnormal current flows through the IGBT 110d. Specifically, when an overcurrent or a short-circuit current flows in the IGBT 110d, the gate voltage is turned on by discharging the charge from the gate of the IGBT 110d more slowly than the off-drive circuit 122 instead of the off-drive circuit 122. This is a circuit that is lower than the threshold voltage to be turned off and the IGBT 110d is turned off. The blocking circuit 124 includes a blocking FET 124a and a blocking resistor 124b.

  The blocking FET 124a is a switching element that discharges charges from the gate of the IGBT 110d when turned on. Specifically, it is an N-channel MOSFET. The source of the blocking FET 124a is connected to the ground for the high voltage battery insulated from the vehicle body, and is connected to the negative terminal of the driving power supply circuit 120 and the emitter of the IGBT 110d via the ground for the high voltage battery. Further, the drain is connected to the gate of the IGBT through the blocking resistor 124b. Further, the gate is connected to the control circuit 128.

  The overcurrent detection circuit 126 is a circuit that detects whether or not an overcurrent flows through the IGBT 110d. Specifically, it is a circuit that determines that an overcurrent is flowing through the IGBT 110d when the current flowing through the IGBT 110d becomes larger than the overcurrent threshold. The input terminal of the overcurrent detection circuit 126 is connected to one end of the current sense resistor 111d. The output terminal is connected to the control circuit 128.

  The short circuit detection circuit 127 is a circuit that detects whether or not the IGBT 110d is in a short circuit state. Specifically, when the current flowing through the IGBT 110d becomes larger than the short-circuit current threshold greater than the overcurrent threshold, both the IGBTs 110a and 110d are in a short-circuited state, and the circuit determines that the short-circuit current is flowing through the IGBT 110d. The input terminal of the short circuit detection circuit 127 is connected to one end of the current sense resistor 111d. The output terminal is connected to the control circuit 128.

  The control circuit 128 controls the on-drive circuit 121 and the off-drive circuit 122 based on a drive signal input from the outside to drive the IGBT 110d, and the off-hold circuit 123 based on the gate voltage of the IGBT 110d. This is a circuit that controls and maintains the off state of the IGBT 110d. In addition, when the on-drive FET 121a or the off-drive FET 122a is turned on due to an on failure or malfunctions and the IGBT 110d becomes in an abnormal state, the operation of the drive power supply circuit 120 is stopped and the IGBT 110d is turned off. It is also a circuit that outputs an abnormal signal to the outside. Further, when an overcurrent flows through the IGBT 110d or when the IGBT 110d is short-circuited, the circuit is also a circuit that controls the cutoff circuit 124 to turn off the IGBT 110d instead of the off-drive circuit 122.

  The control circuit 128 is connected to the gates of the on-drive FET 121a and the off-drive FET 122a, respectively. Further, in order to detect the gate voltage of the IGBT 110d, the gate voltage is connected to the gate of the IGBT 110d and is connected to the gate of the off-holding FET 123a through the gate resistor 123b. Further, it is connected to the control terminal of the drive power supply circuit 120. In addition, they are connected to the output terminals of the overcurrent detection circuit 126 and the short-circuit detection circuit 127 and the gate of the blocking FET 124a, respectively.

  Here, the drive power supply circuit 120, the ON drive FET 120a, the OFF drive FET 122a, the cutoff FET 124a, the overcurrent detection circuit 126, the short circuit detection circuit 127, and the control circuit 128 are integrally configured as an IC.

  Next, the operation of the motor control device will be described with reference to FIG. When the ignition switch (not shown) of the vehicle is turned on, the motor control device 1 shown in FIG. 1 starts its operation. The DC high voltage of the high voltage battery B1 is smoothed by the smoothing capacitor 10. The control device 12 controls the IGBTs 110a to 110f constituting the inverter device 11 based on a drive signal input from the outside. The inverter device 11 converts the DC high voltage smoothed by the smoothing capacitor 10 into a three-phase AC voltage and supplies it to the vehicle drive motor M1. In this way, the motor control device 1 controls the vehicle drive motor M1.

  Next, with reference to FIG. 2 to FIG. 5, the IGBT driving operation in a normal state and the operation when it is determined that the IGBT is in an abnormal state due to an on failure or the like of the on driving FET or the off driving FET are described. To do. Here, FIG. 3 shows a drive signal in a normal state, a timing chart of the on-drive FET and the off-drive FET, a current flowing through each FET, and a gate voltage waveform of the IGBT. FIG. 4 shows a drive signal, a timing chart of the on-drive FET and the off-drive FET, a current flowing through each FET, and a gate voltage waveform of the IGBT when the on-drive FET is turned on. FIG. 5 shows a drive signal, a timing chart of the on-drive FET and the off-drive FET, a current flowing through each FET, and a gate voltage waveform of the IGBT when the off-drive FET is turned on. 3 to 5, the current flowing in the on-drive FET and the current flowing in the off-drive FET are shown as positive in the direction of flowing into the gate of the IGBT and negative in the direction of flowing out of the gate of the IGBT. The waveform drawn with a broken line in FIGS. 4 and 5 is a waveform in a normal state. Also, t1 to t4 in FIG. 4 are the same timings as t1 to t4 in FIG. 3, and t1 and t2 in FIG. 5 are the same timings as t1 and t2 in FIG.

  In FIG. 2, the control circuit 128 drives the IGBT 110d by controlling the on-drive FET 121a and the off-drive FET 122a based on a drive signal input from the outside.

  As shown in FIG. 3, when the drive signal instructs to turn on the IGBT 110d (t1), the control circuit 128 turns off the off drive FET 122a and turns on the on drive FET 121a. As a result, current flows from the driving power supply circuit 120 to the gate of the IGBT 110d through the on-driving FET 121a and the on-driving resistor 121b for a time Ton, and charges are charged (t2). As a result, the gate voltage becomes higher than the threshold voltage for turning on and off, and the IGBT 110d is turned on.

  On the other hand, when the drive signal instructs to turn off the IGBT 110d (t3), the control circuit 128 turns off the on-drive FET 121a and turns on the off-drive FET 122a. As a result, current flows from the gate of the IGBT 110d through the off-drive resistor 122b and the off-drive FET 122a for a time Toff, and the charge is discharged (t4). As a result, the gate voltage becomes lower than the threshold voltage for turning on and off, and the IGBT 110d is turned off. Then, when the gate voltage becomes equal to or lower than the off-holding threshold value lower than the on-off threshold voltage, the control circuit 128 turns on the off-holding FET 123a in FIG. As a result, a current flows from the gate of the IGBT 110d through the off-holding FET 123a, the electric charge is further discharged, and the off-state of the IGBT 110d is held.

  By the way, when the current flowing through the IGBT 110d becomes larger than the overcurrent threshold, the overcurrent detection circuit 126 determines that the overcurrent is flowing through the IGBT 110d. When the overcurrent detection circuit 126 determines that the current is an overcurrent, the control circuit 128 turns on the blocking FET 124a in place of the off drive FET 122a. As a result, a current flows from the gate of the IGBT 110d through the blocking resistor 124b and the blocking FET 124a, and the charge is discharged. As a result, the gate voltage becomes lower than the threshold voltage at which the gate voltage is gradually turned on and off as compared with the off drive circuit 122, and the IGBT 110d is turned off.

  Further, when the current flowing through the IGBT 110d becomes larger than the short-circuit current threshold, the short-circuit detection circuit 127 determines that both the IGBTs 110a and 110d are in a short-circuit state. When the short circuit detection circuit 127 determines that the short circuit is present, the control circuit 128 turns on the blocking FET 124a and turns off the IGBT 110d, similarly to the case where it is determined that the current is an overcurrent.

  When the on-drive FET 121a is turned on due to an on-failure or malfunction, the drive signal instructs the IGBT 110d to turn off as shown in FIG. 4 (t3), and the control circuit 128 tries to turn off the on-drive FET 121a. However, the on-drive FET 121a cannot be turned off. Therefore, a current that does not flow in a normal state flows from the drive power supply circuit 120 to the gate of the IGBT 110d through the on-drive FET 121a and the on-drive resistor 121b. Further, even after the time Toff has elapsed, a current that does not flow in a normal state flows out from the gate of the IGBT 110d through the off-drive resistor 122b and the off-drive FET 122a. As a result, the gate voltage of the IGBT 110d does not sufficiently decrease, and an abnormal state in which the IGBT 110d cannot be turned off occurs.

  However, the control circuit 128 detects the current flowing through the on-driving FET 121a based on the voltage across the terminals of the on-driving resistor 121b. Even when the drive signal instructs the IGBT 110d to be turned off, when the current flows through the on-drive FET 121a, the operation of the drive power supply circuit 120 is stopped and the voltage from the drive power supply circuit 120 is reduced. Shut off the supply. As a result, the gate voltage becomes lower than the threshold voltage for turning on and off, and the IGBT 110d is turned off. That is, the IGBT 110d is turned off except for the off-drive FET 122a (other than the off-drive switching element).

  Further, when the off drive FET 122a is turned on due to an on failure or malfunction, as shown in FIG. 5, the drive signal instructs the IGBT 110d to be turned on (t1), and the control circuit 128 tries to turn off the off drive FET 122a. However, the off-drive FET 122a cannot be turned off. Therefore, even after the time Ton has elapsed, a current that does not flow in the normal state flows from the drive power supply circuit 120 to the gate of the IGBT 110d through the on-drive FET 121a and the on-drive resistor 121b. In addition, a current that does not flow in a normal state flows from the gate of the IGBT 110d through the off-drive resistor 122b and the off-drive FET 122a. As a result, the gate voltage of the IGBT 110d does not rise sufficiently, and an abnormal state in which the IGBT 110d cannot be turned on occurs.

  However, the control circuit 128 detects the current flowing through the on-drive FET 221a based on the voltage across the terminals of the on-drive resistor 221b. When the drive signal instructs the IGBT 110d to be turned on and the current is flowing in the on-drive FET 121a even though the time Ton has elapsed (predetermined time has elapsed), the operation of the drive power supply circuit 120 is stopped and the drive is performed. The voltage supply from the power supply circuit 120 is cut off. As a result, the gate voltage becomes lower than the threshold voltage for turning on and off, and the IGBT 110d is turned off. That is, the IGBT 110d is turned off except for the off-drive FET 122a.

  Next, the effect will be described. According to the first embodiment, when the drive signal instructs to turn off the IGBT 110d, the control circuit 128 turns off the on-drive FET 121a and turns on the off-drive FET 122a. Thereby, the IGBT 110d is turned off. However, when the on-driving FET 121a is turned on due to an on-failure or malfunction, a current that does not flow in a normal state flows to the on-driving FET 121a as shown in FIG. Then, the gate voltage of the IGBT 110d is not sufficiently lowered, and an abnormal state in which the IGBT 110d cannot be turned off occurs. When the gate voltage is within a predetermined range near the on / off threshold voltage, the collector-emitter voltage, that is, the on-voltage increases, and the heat generation of the IGBT 110d increases. If such an abnormal state continues, the IGBT 110d may generate heat and be thermally destroyed. However, the control circuit 128 determines that the IGBT 110d is in an abnormal state when a current flows through the on-drive FET 121a even though the drive signal instructs the IGBT 110d to turn off. Then, the IGBT 110d is turned off except for the off-drive FET 121a. Therefore, even if the on-drive FET 121a is in an abnormal state in which the IGBT 110d cannot be turned off due to an on failure or the like, it is possible to prevent thermal destruction of the IGBT 110d.

  According to the first embodiment, the control circuit 128 detects the current flowing through the on-drive FET 121a based on the voltage across the terminals of the on-drive resistor 121b. Therefore, it is possible to reliably determine whether or not current is flowing through the on-drive FET 121a without newly providing a current detection resistor.

  According to the first embodiment, the resistance value of the on-drive resistor 121b is set in consideration of the amount of current required when charging the gate of the IGBT 110d. The current required for charging the gate of the IGBT 110d varies depending on the ambient temperature during operation. However, the current required for charging the gate of the IGBT 110d is a value that takes into account the ambient temperature of the IGBT 110d during operation. For this reason, even when the ambient temperature rises during operation, the resistance value can be set while suppressing the current necessary for charging the gate of the IGBT 110d. Therefore, the loss of the on-drive resistor 121b can be suppressed.

  According to the first embodiment, when the IGBT 110d is in an abnormal state, the IGBT 110d is turned off by cutting off the voltage to the gate for driving the IGBT 110d. Therefore, thermal destruction of the IGBT 110d can be prevented.

  According to the first embodiment, the abnormal state of the IGBT 110d can be notified to the outside.

  According to the first embodiment, when the drive signal instructs to turn on the IGBT 110d, the control circuit 128 turns off the off drive FET 122a and turns on the on drive FET 121a. Thereby, the IGBT 110d is turned on. However, when the off-drive FET 122a is turned on due to an on-failure or malfunction, as shown in FIG. 5, it flows in a normal state even though the time Ton for charging the gate of the IGBT 110d has elapsed. Current flows to the on-drive FET 121a. Then, the gate voltage of the IGBT 110d does not rise sufficiently, and an abnormal state in which the IGBT 110d cannot be turned on occurs. When the gate voltage is within a predetermined range near the on / off threshold voltage, the collector-emitter voltage, that is, the on-voltage increases, and the heat generation of the IGBT 110d increases. If such an abnormal state continues, the IGBT 110d may generate heat and be thermally destroyed. However, the control circuit 128 indicates that the IGBT 110d is turned on when the drive signal instructs the IGBT 110d to turn on and the time Ton for charging the gate of the IGBT 110d elapses, but the current flows in the on-drive FET 121a. Is determined to be in an abnormal state. Then, the IGBT 110d is turned off except for the off-drive FET 122a. Therefore, even when the off-drive FET 122a is in an abnormal state in which the IGBT 110d cannot be turned on due to an on-failure or the like, the thermal destruction of the IGBT 110d can be prevented.

  In the first embodiment, when the control circuit 128 determines that the IGBT 110d is in an abnormal state, it stops the operation of the drive power supply circuit 120 and cuts off the supply of voltage from the drive power supply circuit 120. Although the example which turns off IGBT110d is given, it is not restricted to this. The IGBT 110d may be turned off by controlling the off-holding FET 123a. In this case, the IGBT 110d can be turned off by turning on the off-holding FET 123a and discharging the charge from the gate of the IGBT 110d. Therefore, thermal destruction of the IGBT 110d can be prevented.

  Further, the IGBT 110d may be turned on. When IGBT 110a shown in FIG. 2 is turned on, both IGBTs 110a and 110d connected in series are turned on, and a short-circuit current flows through IGBTs 110a and 110d. When a short-circuit current flows through the IGBT 110a, the control circuit or the like (drive circuit) that controls the IGBT 110a turns off the IGBT 110a as in the case of the IGBT 110d. Therefore, the short circuit current flowing through the IGBT 110d can be cut off. Therefore, thermal destruction of the IGBT 110d can be prevented.

(Second Embodiment)
Next, the motor control device of the second embodiment will be described. The motor control device according to the second embodiment is different from the motor control device according to the first embodiment in that the current flowing through the on-drive FET is detected based on the voltage of the on-drive resistor, while the drive power supply circuit is turned on. Based on the voltage of the current detection resistor provided between the drive FETs, the current flowing through the on-drive FET is detected. The motor control device of the second embodiment has the same configuration as the motor control device of the first embodiment except for the on-drive circuit.

  First, the configuration of the control device and the operation when it is determined that the IGBT is in an abnormal state will be described with reference to FIG. Here, FIG. 6 is a circuit diagram of the control device in the second embodiment. Here, a different part from 1st Embodiment is demonstrated, and description is abbreviate | omitted except a required part about a common part.

  As shown in FIG. 6, the control device 22 has a driving power supply circuit 220, an on driving circuit 221, an off driving circuit 222, an off holding circuit 223, and a blocking circuit 224 with respect to the IGBT 210 d. , An overcurrent detection circuit 226, a short circuit detection circuit 227, and a control circuit 228. The IGBT 210d and the current sense resistor 211d correspond to the IGBT 110d and the current sense resistor 111d of the first embodiment. The drive power supply circuit 220, the off drive circuit 222, the off hold circuit 223, the cutoff circuit 224, the overcurrent detection circuit 226, and the short circuit detection circuit 227 are the same as the drive power supply circuit 120 and the off drive circuit of the first embodiment. 122, the off-holding circuit 123, the cutoff circuit 124, the overcurrent detection circuit 126, and the short-circuit detection circuit 127.

  The on-drive circuit 221 includes an on-drive FE 221a, an on-drive resistor 221b, and a current detection resistor 221c. The on-drive FE 221a and the on-drive resistor 221b have the same configuration as the on-drive FE 121a and the on-drive resistor 121b of the first embodiment.

  The current detection resistor 221c is a resistor that detects a current flowing through the on-drive FET 221a. One end of the current detection resistor 221c is connected to the positive terminal of the drive power supply circuit, and the other end is connected to the source of the on-drive FET 221a. Further, both ends of the current detection resistor 221c are connected to the control circuit 228.

  Here, the resistance value of the current detection resistor 221c is set in consideration of the magnitude of the current required when charging the gate of the IGBT 210d. The current required for charging the gate of the IGBT 210d is a value that takes into account the ambient temperature of the IGBT 210d during operation. That is, the resistance value is set according to the current capacity of the IGBT in consideration of the ambient temperature of the IGBT during operation.

  The control circuit 228 determines whether or not a current is flowing through the on-drive FET 221a based on the voltage between the terminals of the current detection resistor 221c. Even when the drive signal instructs the IGBT 210d to turn off, when the current flows through the on-drive FET 221a, the operation of the drive power supply circuit 220 is stopped, and the voltage from the drive power supply circuit 220 is reduced. Shut off the supply. Similarly, when the drive signal instructs to turn on the IGBT 210d and the current is flowing in the on-drive FET 221a even though the time Ton has elapsed, the supply of voltage from the drive power supply circuit 220 is cut off in the same manner. .

  Next, the effect will be described. According to the second embodiment, the current detection resistor 221c provided between the drive power supply circuit 220 and the on-drive FET 221a can reliably determine whether or not current is flowing through the on-drive FET 221a. it can.

  According to the second embodiment, the resistance value of the current detection resistor 221c is set in consideration of the magnitude of the current required when charging the gate of the IGBT 210d. The current required for charging the gate of the IGBT 210d varies depending on the ambient temperature during operation. However, the current required for charging the gate of the IGBT 210d is a value considering the ambient temperature of the IGBT 210d during operation. Therefore, even when the ambient temperature rises during operation, the resistance value can be set while suppressing the current while securing the current necessary for charging the gate of the IGBT 210d. Therefore, the loss of the current detection resistor 221c can be suppressed.

  In the second embodiment, the current detection resistor 221c is provided between the drive power supply circuit 220 and the on-drive FET 221a. However, the present invention is not limited to this. As shown in FIG. 7, it may be provided between the power supply circuit and the drive power supply circuit 220. When a current flows from the drive power supply circuit 220 to the on-drive FET 221a, a current also flows from the power supply circuit to the drive power supply circuit 220. Therefore, even with such a configuration, it can be determined whether or not a current is flowing through the on-drive FET 221a.

  In the second embodiment, an example is described in which it is determined whether or not current is flowing in the on-drive FET 221a based on the voltage across the terminals of the current detection resistor 221c. However, the present invention is not limited to this. As shown in FIG. 8, the control circuit 228 is connected to the positive terminal of the drive power supply circuit 220, and it is determined whether or not current is flowing through the on-drive FET 221a based on the voltage of the drive power supply circuit 220. May be. When a current flows from the drive power supply circuit 220 to the on-drive FET 221a, the voltage of the drive power supply circuit 220 decreases. Therefore, even with such a configuration, it is possible to determine whether or not a current is flowing through the on-drive FET 221a based on the voltage of the drive power supply circuit 220.

(Third embodiment)
Next, the motor control apparatus of 3rd Embodiment is demonstrated. The motor control device of the third embodiment turns off the IGBT gate voltage while the motor control device of the first embodiment cuts off the voltage supply from the drive power supply circuit and turns off the IGBT when the IGBT is abnormal. The IGBT is clamped below the holding threshold value, and the IGBT is turned off by the off holding circuit. The motor control device of the third embodiment has the same configuration as the motor control device of the first embodiment except for the control device.

  First, the configuration of the control device will be described with reference to FIG. Here, FIG. 9 is a circuit diagram of the control device in the third embodiment. Here, a different part from the control apparatus of 1st Embodiment is demonstrated, and description is abbreviate | omitted except a required part about a common part.

  As shown in FIG. 5, the control device 32 has a drive power supply circuit 320, an on drive circuit 321, an off drive circuit 322, an off holding circuit 323, and a cutoff circuit 324 with respect to the IGBT 310 d. The overcurrent detection circuit 326, the short circuit detection circuit 327, and the control circuit 328 are provided. Further, a voltage clamp circuit 329 is provided. The IGBT 310d and the current sense resistor 311d correspond to the IGBT 110d and the current sense resistor 111d of the first embodiment. The drive power supply circuit 320, the on drive circuit 321, the off drive circuit 322, the off hold circuit 323, the cutoff circuit 324, the overcurrent detection circuit 326, and the short circuit detection circuit 327 are the drive power supply circuit of the first embodiment. 120, the on-drive circuit 121, the off-drive circuit 122, the off-hold circuit 123, the cutoff circuit 124, the overcurrent detection circuit 126, and the short-circuit detection circuit 127.

  The voltage clamp circuit 329 is a circuit that clamps the gate voltage of the IGBT 310d to be equal to or lower than an off-hold threshold. The voltage clamp circuit 329 includes a voltage clamp FET 329a and a constant voltage diode 329b. The voltage of the constant voltage diode 329b is set to be a constant voltage equal to or lower than the off-hold threshold. The voltage clamping FET 329a is a switching element that, when turned on, connects the constant voltage diode 329b to the gate of the IGBT 320d. Specifically, it is an N-channel MOSFET. The source of the voltage clamping FET 329a is connected to the ground for the high voltage battery insulated from the vehicle body, and is connected to the negative terminal of the driving power supply circuit 320 and the emitter of the IGBT 310d via the ground for the high voltage battery. The drain is connected to the gate of the IGBT 320d via the constant voltage diode 329b. Specifically, the anode of the constant voltage diode 329b is connected, and the cathode of the constant voltage diode 329b is connected to the gate of the IGBT 320d. Further, the gate of the voltage clamping FET 329 a is connected to the control circuit 328.

  Next, an operation when it is determined that the IGBT is in an abnormal state will be described with reference to FIG. The control circuit 328 detects the current flowing through the on-drive FET 321a based on the voltage across the terminals of the on-drive resistor 321b. Even when the drive signal instructs to turn off the IGBT 310d, when the current flows through the on-drive FET 321a, the voltage clamp circuit 329 is activated to make the gate voltage of the IGBT 310d equal to or less than the off-hold threshold. Specifically, the voltage clamping FET 329a is turned on, and the gate voltage of the IGBT 310d is set to be equal to or lower than the off holding threshold set by the constant voltage diode 329b. As a result, the off-holding FET 323a is turned on, the charge is discharged from the gate of the IGBT 310d, and the IGBT 310d is turned off. Similarly, the IGBT 310d is turned off even when a current flows through the on-driving FET 321a even though the drive signal instructs the IGBT 310d to turn on and the time Ton has elapsed.

  Next, the effect will be described. According to the third embodiment, the control signal 328 instructs the IGBT 310d to turn on when a current flows through the on-drive FET 321a even though the drive signal instructs the IGBT 310d to turn off. Even when the time Ton has elapsed, when the current flows through the on-drive FET 321a, the voltage clamp circuit 329 is activated to set the gate voltage of the IGBT 310d below the off-hold threshold. Therefore, the off-holding FET 323a can discharge the charge from the gate of the IGBT 310d to turn off the IGBT 310d. Therefore, thermal destruction of the IGBT 310d can be prevented.

(Fourth embodiment)
Next, a motor control device according to a fourth embodiment will be described. In the motor control device of the fourth embodiment, the motor control device of the first embodiment cuts off the voltage supply from the drive power supply circuit and turns off the IGBT when the IGBT is abnormal, whereas the gate of the IGBT is driven on. The IGBT is cut off from the FET for off and the FET for off drive. The motor control device of the fourth embodiment has the same configuration as the motor control device of the first embodiment except for the control device.

  First, the configuration of the control device will be described with reference to FIG. Here, FIG. 10 is a circuit diagram of the control device in the fourth embodiment. Here, a different part from the control apparatus of 1st Embodiment is demonstrated, and description is abbreviate | omitted except a required part about a common part.

  As shown in FIG. 10, the control device 42 has a driving power supply circuit 420, an on-driving circuit 421, an off-driving circuit 422, an off-holding circuit 423, and a blocking circuit 424 with respect to the IGBT 410d. , An overcurrent detection circuit 426, a short circuit detection circuit 427, and a control circuit 428. Further, a gate blocking FET 429 is provided. The IGBT 410d and the current sense resistor 411d correspond to the IGBT 110d and the current sense resistor 111d of the first embodiment. The drive power supply circuit 420, the on drive circuit 421, the off drive circuit 422, the off hold circuit 423, the cutoff circuit 424, the overcurrent detection circuit 426, and the short circuit detection circuit 427 are the drive power supply circuit of the first embodiment. 120, the on-drive circuit 121, the off-drive circuit 122, the off-hold circuit 123, the cutoff circuit 124, the overcurrent detection circuit 126, and the short-circuit detection circuit 127.

  The gate blocking FET 429 is a switching element that blocks the gate of the IGBT 410d from the on driving FET 421a and the off driving FET 422a. Specifically, it is an N-channel MOSFET. The source of the gate blocking FET 429 is connected to the gate of the IGBT 410d. The drain is connected to the on-drive FET 421a via the on-drive resistor 421b and is connected to the off-drive FET 422a via the off-drive resistor 422b. Further, the gate is connected to the control circuit 428.

  Next, an operation when it is determined that the IGBT is in an abnormal state will be described with reference to FIG. The control circuit 428 detects the current flowing through the on-drive FET 421a based on the voltage across the terminals of the on-drive resistor 421b. When the current is flowing through the on-drive FET 321a even though the drive signal instructs the IGBT 310d to be turned off, the gate of the IGBT 410d is cut off from the on-drive FET 421a and the off-drive FET 422a. As a result, the supply of voltage to the gate for driving the IGBT 410d is cut off, and the IGBT 410d is turned off. Similarly, the IGBT 410d is turned off even when a current flows through the on-driving FET 421a even though the drive signal instructs the IGBT 410d to turn on and the time Ton has elapsed.

  Next, the effect will be described. According to the fourth embodiment, the control signal 428 instructs the IGBT 410d to turn on when a current flows through the on-drive FET 421a even though the drive signal instructs the IGBT 410d to turn off. The gate of the IGBT 410d is cut off from the on-driving FET 421a and the off-driving FET 422a when the current is flowing in the on-driving FET 421a despite the time Ton elapses. Therefore, supply of voltage to the gate for driving IGBT 410d is cut off, and IGBT 410d is turned off. Therefore, thermal destruction of the IGBT 410d can be prevented.

DESCRIPTION OF SYMBOLS 1 ... Motor control apparatus (electronic device), 10 ... Smoothing capacitor, 11 ... Inverter apparatus, 110a ... IGBT (2nd switching element), 110b, 110c, 110e, 110f ... IGBT, 110d, 210d, 310d, 410d ... IGBT (first switching element), 111a to 111f, 211d, 311d, 411d ... current sense resistor, 12, 22, 32, 42 ... control device, 120, 220 , 320, 420... Driving power supply circuit, 121, 221, 321, 421... ON driving circuit, 121 a, 221 a, 321 a, 421 a... ON driving FET (ON driving switching element), 121 b 221b, 321b, 421b... ON driving resistance, 221c... Current detection resistance, 12 , 222, 322, 422... Off drive circuit, 122 a, 222 a, 322 a, 422 a... Off drive FET (off drive switching element), 122 b, 222 b, 322 b, 422 b. , 123, 223, 323, 423 ... off holding circuit, 123a, 223a, 323a, 423a ... off holding FET (off holding switching element), 123b, 223b, 323b, 423b ... gate resistance , 124, 224, 324, 424... Blocking circuit, 124 a, 224 a, 324 a, 424 a... Blocking FET, 124 b, 224 b, 324 b, 424 b... Blocking resistor, 126, 226, 326, 426 ... Overcurrent detection circuit, 127, 227, 327, 427 ... Short circuit detection circuit, 1 8, 228, 328, 428 ... control circuit, 329 ... voltage clamp circuit, 329a ... voltage clamp FET, 329b ... constant voltage diode, 429 ... gate cutoff FET, B1,.・ High voltage battery, M1 ... Vehicle drive motor

Claims (13)

A first switching element driven by controlling the voltage of the control terminal;
A driving power supply circuit for supplying a voltage for driving the first switching element;
One end is connected to the output terminal of the drive power supply circuit, and the other end is connected to the control terminal of the first switching element, and when turned on, the control terminal of the first switching element is charged with charge. Switching element for
An off-drive switching element that is connected to the control terminal of the first switching element and discharges electric charge from the control terminal of the first switching element by being turned on;
Control for driving the first switching element by controlling the voltage of the control terminal of the first switching element by controlling the on-driving switching element and the off-driving switching element based on the input driving signal. Circuit,
In an electronic device comprising:
A cutoff switching element that is connected to the control terminal of the first switching element and discharges electric charge from the control terminal of the first switching element by being turned on;
When an abnormal current flows through the first switching element, the control circuit controls the blocking switching element to turn off the first switching element, and a drive signal instructs the first switching element to turn off. However, when a current flows through the on-drive switching element, it is determined that the first switching element is in an abnormal state, and the cutoff switching element is controlled to turn off the first switching element. An electronic device characterized by: The other end of the on-drive switching element is connected to the control terminal of the first switching element via an on-drive resistor,
The electronic device according to claim 1 , wherein the control circuit determines whether a current is flowing through the on-drive switching element based on a voltage of the on-drive resistor. One end of the on-drive switching element is connected to the output terminal of the drive power circuit via a current detection resistor,
2. The electronic device according to claim 1 , wherein the control circuit determines whether or not a current flows in the on-drive switching element based on a voltage of the current detection resistor. The drive power supply circuit has an input terminal connected to the power supply circuit via a current detection resistor, converts a voltage of the power supply circuit, and supplies a voltage for driving the first switching element,
2. The electronic device according to claim 1 , wherein the control circuit determines whether or not a current flows in the on-drive switching element based on a voltage of the current detection resistor. 2. The electronic device according to claim 1 , wherein the control circuit determines whether or not a current flows through the on-driving switching element based on a voltage of the driving power supply circuit. The resistance of the on-drive resistor, to claim 2, characterized in that it is set in consideration of the magnitude of the current required when electric charge is applied to the control terminal of the first switching element The electronic device described. Current required when electric charge is applied to the control terminal of the first switching element, according to claim 6, characterized in that takes into account the ambient temperature of the first switching element during operation Electronic equipment. Resistance of the current detecting resistor, claim 3 or, characterized in that it is set in consideration of the magnitude of the current required when electric charge is applied to the control terminal of the first switching element 5. The electronic device according to 4 . 9. The current according to claim 8 , wherein the current required for charging the control terminal of the first switching element is based on an ambient temperature of the first switching element during operation. Electronic equipment. A second switching element driven by controlling the voltage of the control terminal and connected in series to the first switching element;
The second switching element is driven by controlling the voltage of the control terminal of the second switching element based on the input drive signal, and the second switching element is operated when an abnormal current flows through the second switching element. A drive circuit for turning off the element;
Have
It said control circuit when said first switching element is determined to be in the abnormal state, the electronic device according to any one of claims 1 to 9, wherein turning on the first switching element.   A first switching element driven by controlling the voltage of the control terminal;
  A driving power supply circuit for supplying a voltage for driving the first switching element;
  One end is connected to the output terminal of the drive power supply circuit, and the other end is connected to the control terminal of the first switching element, and when turned on, the control terminal of the first switching element is charged with charge. Switching element for
  An off-drive switching element that is connected to the control terminal of the first switching element and discharges electric charge from the control terminal of the first switching element by being turned on;
  Control for driving the first switching element by controlling the voltage of the control terminal of the first switching element by controlling the on-driving switching element and the off-driving switching element based on the input driving signal. Circuit,
In an electronic device comprising:
  A second switching element driven by controlling the voltage of the control terminal and connected in series to the first switching element;
  The second switching element is driven by controlling the voltage of the control terminal of the second switching element based on the input drive signal, and the second switching element is operated when an abnormal current flows through the second switching element. A drive circuit for turning off the element;
Have
  The control circuit determines that the first switching element is in an abnormal state when a current is flowing through the on-driving switching element even though the drive signal instructs the first switching element to be turned off. An electronic apparatus comprising: determining and turning on the first switching element. Said control circuit, when said first switching element is determined to be in the abnormal state, the electronic device according to any one of claims 1 to 11, characterized in that outputs an abnormality signal to the outside. The control circuit instructs the switching element for on-drive to turn on even though a driving signal indicates that the first switching element is turned on and a predetermined time has elapsed for charging the control terminal of the first switching element. when current is flowing, an electronic device according to any one of claims 1 to 11, wherein the first switching element is characterized in that it is determined that an abnormal state.

Images