Drive unit and drive method

Abstract

SOLUTION: A drive device includes a temperature detection circuit that outputs a temperature detection signal according to temperature of a switching element, a current detection circuit that samples a current detection signal according to the current flowing through the switching element at a timing during an on period of the switching element, and a drive circuit that adjusts a drive current supplied to a control terminal of the switching element according to the temperature detection signal and the current detection signal. The drive circuit may make the drive current smaller according to the temperature detection signal indicating that the temperature of the switching element is lower when the current detection signals are the same. The drive circuit may make the drive current smaller according to the current detection signal indicating that a main current is smaller when the temperature detection signals are the same.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a driving device and a driving method.

Background Art

[0002] Patent Document 1 describes that "the operation temperature of a power semiconductor switching element is not detected constantly, but is detected at a timing according to a control signal from an external control circuit. By detecting the operation temperature at a predetermined timing, for example, the timing when the power semiconductor switching element turns off, the influence of the switching noise of the power semiconductor switching element is reduced compared with the case of constantly detecting the operation temperature. Therefore, the influence of the switching noise of the power semiconductor switching element can be reduced and the magnitude of the current for driving the power semiconductor switching element can be changed" (paragraph 0009).

[0003] Patent Document 2 describes that "the semiconductor device according to this invention, in summary, updates the threshold value for switching the switching speed of an output transistor for driving a load according to the temperature. When the temperature becomes high, the threshold value is lowered" (paragraph 0023), and "the semiconductor device according to this invention includes a temperature sensor that detects the operation temperature of a switching element for driving an output load, and a gate control circuit that changes the threshold value for switching the switching speed of the switching element according to the detection output of this temperature sensor. This gate control circuit lowers the threshold value when the detection output of the temperature sensor indicates a temperature rise" (paragraph 0024).

[0004] Patent Document 3 describes that "the invention of claim 1 increases the gate resistance value to reduce noise generation when the load current is below a predetermined value, and reduces the gate resistance when the load current exceeds the predetermined value and the element temperature exceeds a predetermined temperature, thereby reducing the switching loss and preventing thermal breakdown" (paragraph 0018). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Unexamined Patent Publication No. 2019-110677 [Patent Document 2] Japanese Unexamined Patent Publication No. 2008-182835 [Patent 3 Japanese Patent Publication No. 2003-274672 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] It is desirable to realize a drive system that effectively reduces switching loss and switching noise according to the temperature of the switching element and the current flowing through the switching element. [Means for solving the problem]

[0006] In a first embodiment of the present invention, a drive device is provided. The drive device may include a temperature detection circuit that outputs a temperature detection signal corresponding to the temperature of a switching element. The drive device may include a current detection circuit that samples a current detection signal corresponding to the main current flowing through the switching element during the ON period of the switching element. The drive device may include a drive circuit that adjusts the drive current supplied to the control terminal of the switching element according to the temperature detection signal and the current detection signal.

[0007] The drive circuit may reduce the drive current in response to a temperature detection signal indicating a lower temperature of the switching element, provided that the current detection signals are the same.

[0008] The drive circuit may reduce the drive current in response to a current detection signal indicating that the main current is smaller, provided that the temperature detection signals are the same.

[0009] The drive circuit may set the magnitude of the drive current to a value corresponding to the first temperature range, regardless of the value of the current detection signal, depending on whether the temperature indicated by the temperature detection signal falls within the first temperature range among multiple temperature ranges. The drive circuit may adjust the magnitude of the drive current according to the value of the current detection signal, depending on whether the temperature indicated by the temperature detection signal falls within the second temperature range among multiple temperature ranges.

[0010] The second temperature range is the temperature range with the lowest temperature among multiple temperature ranges, and the first temperature range may be any temperature range other than the temperature range with the lowest temperature among multiple temperature ranges.

[0011] The drive circuit may set the magnitude of the drive current to a magnitude corresponding to a combination of a temperature range that includes the temperature indicated by the temperature detection signal from among a plurality of temperature ranges, and a current range that includes the current value indicated by the current detection signal from among a plurality of current ranges.

[0012] The drive circuit may include a current mirror circuit that outputs a drive current which is an amplified version of the supplied current. The drive circuit may include a voltage output circuit that outputs a control voltage corresponding to a temperature detection signal and a current detection signal. The drive circuit may include a current control circuit that supplies a current corresponding to the control voltage to the current mirror circuit.

[0013] The drive circuit may include a current mirror circuit that outputs a drive current which is an amplified version of the supplied current. The drive circuit may also include a current control circuit that supplies a current to the current mirror circuit in accordance with a temperature detection signal and a current detection signal.

[0014] The drive circuit may include a current mirror circuit that outputs a drive current which is an amplified version of the supplied current. The drive circuit may also include an amplification factor setting circuit that sets the amplification factor of the current mirror circuit according to a temperature detection signal and a current detection signal.

[0015] In a second aspect of the present invention, a driving method is provided. The driving method may include a temperature detection circuit outputting a temperature detection signal corresponding to the temperature of the switching element. The driving method may include a current detection circuit outputting a current detection signal corresponding to the main current flowing through the switching element. The driving method may include a driving circuit adjusting a driving current supplied to the control terminal of the switching element according to the temperature detection signal and the current detection signal.

[0016] Note that the above summary of the invention does not list all the features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0017] [Figure 1] The configuration of the device 5 according to this embodiment is shown. [Figure 2] The configuration of the temperature detection circuit 130 according to this embodiment is shown. [Figure 3] The relationship between the input to the temperature detection circuit 130 according to this embodiment and the temperature is shown. [Figure 4] The input and output of the temperature detection circuit 130 according to this embodiment are shown. [Figure 5] The configuration of the current detection circuit 140 according to this embodiment is shown. [Figure 6] The configuration of the voltage output circuit 160 according to this embodiment is shown. [Figure 7] The input and output of the voltage output circuit 160 according to this embodiment are shown. [Figure 8] The configuration of the switching circuit 170 according to this embodiment is shown. [Figure 9] The noise reduction effect of the device 5 according to this embodiment in the low current region is shown. [Figure 10] The loss reduction effect of the device 5 according to this embodiment in the medium and large current regions is shown. [Figure 11] The switching speed of the device 5 according to this embodiment according to the temperature is shown. [Figure 12] The loss reduction effect of the device 5 according to this embodiment according to the temperature is shown. [Figure 13] Shows the configuration of the voltage output circuit 1300 according to the first modification example of the present embodiment. [Figure 14] Shows the input and output of the voltage output circuit 1300 according to the first modification example of the present embodiment. [Figure 15] Shows the configuration of the device 1500 according to the second modification example of the present embodiment. [Figure 16] Shows the configuration of the switching circuit 1570 according to the second modification example of the present embodiment. [Figure 17] Shows the configuration of the switching circuit 1700 according to the third modification example of the present embodiment. [Figure 18] Shows the input and output of the decoder circuit 1710 according to the third modification example of the present embodiment. [Figure 19] Shows the configuration of the voltage output circuit 1900 according to the fourth modification example of the present embodiment.

Mode for Carrying Out the Invention

[0018] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0019] FIG. 1 shows the configuration of the device 5 according to the present embodiment. The device 5 includes a drive element 10 and a drive device 100.

[0020] The device 5 includes a switching element 15 and a temperature sensor 40. The switching element 15 is a semiconductor switching element such as an IGBT (insulated gate bipolar transistor) or a MOSFET (metal-oxide-semiconductor field-effect transistor). The switching element 15 may be a SiC-IGBT or SiC-MOSFET that can switch at a higher speed. The switching element 15 has a first main terminal and a second main terminal, and a control terminal that controls the connection state between the first main terminal and the second main terminal. The switching element 15 has a collector ("C" in the figure) and an emitter ("E" in the figure) as the first main terminal and the second main terminal, and a gate ("G" in the figure) as the control terminal. When the switching element 15 is a MOSFET, the switching element 15 has a drain and a source as the first main terminal and the second main terminal, and a gate as the control terminal. In this embodiment, for the sake of explanation, the case where the switching element 15 is an IGBT will be shown.

[0021] The switching element 15 includes a main switching element 20 as a main cell that carries the main current and a sense switching element 30 as a current sense cell that carries the sense current. The main cell is connected between the collector and emitter, and the current sense cell is connected between the collector and sense emitter, with the gate of the switching element 15 connected to the gates of both the main cell and the current sense cell. The area ratio of the current sense cell to the main cell is set to less than 1 / 1000, and in a steady state, it carries a sense current at a ratio (e.g., 1 / 1000) to the main current that corresponds to the area ratio.

[0022] The temperature sensor 40 is positioned near the switching element 15 and detects the temperature of the switching element 15. In this embodiment, the temperature sensor 40 is, for example, a thermal diode. Alternatively, the temperature sensor 40 may be of another type.

[0023] The drive unit 100 includes a power supply 110, an input buffer 120, a temperature detection circuit 130, a current detection circuit 140, and a drive circuit 150. The power supply 110 is, for example, a voltage regulator. The power supply 110 converts the power supply voltage VCC input from an external source into a power supply voltage VDD used internally by the drive unit 100.

[0024] The input buffer 120 amplifies the control signal IN input from the outside and outputs it as the control signal OUTOFF. The control signal OUTOFF is a signal that instructs the switching element 15 to be disconnected when the logic is H (high) and to be connected when the logic is L (low).

[0025] The temperature detection circuit 130 is connected to the temperature sensor 40 in the drive element 10. The temperature detection circuit 130 receives the detected value OT from the temperature sensor 40 and outputs a temperature detection signal (for example, TL / TM / TH in the figure) corresponding to the temperature of the switching element 15.

[0026] The current detection circuit 140 is connected to the sense terminal SE of the switching element 15 (the emitter terminal of the sense switching element 30) and the input buffer 120. The current detection circuit 140 receives a detection value OC corresponding to the current flowing through the sense terminal SE of the switching element 15 as input and outputs a current detection signal (for example, ILOW in the figure) corresponding to the current flowing through the switching element 15. In this embodiment, the current detection circuit 140 samples the current detection signal corresponding to the current flowing through the switching element 15 during the ON period of the switching element 15 and outputs the sampled result at the end of the ON period of the switching element 15.

[0027] The drive circuit 150 is connected to the input buffer 120, the temperature detection circuit 130, and the current detection circuit 140. The drive circuit 150 switches the switching element 15 on and off by driving the control terminal G (gate) of the switching element 15 in accordance with the control signal OUTOFF. Here, the drive circuit 150 can change the switching speed of the switching element 15 by adjusting the drive current supplied to the control terminal G of the switching element 15 in accordance with the temperature detection signal and the current detection signal.

[0028] The drive circuit 150 includes a voltage output circuit 160 and a switching circuit 170. The voltage output circuit 160 is connected to the temperature detection circuit 130 and the current detection circuit 140. The voltage output circuit 160 outputs a control voltage IDREF corresponding to the temperature detection signals TL / TM / TH from the temperature detection circuit 130 and the current detection signal ILOW from the current detection circuit 140.

[0029] The switching circuit 170 is connected to the input buffer 120 and the voltage output circuit 160. The switching circuit 170 drives the control terminal G of the switching element 15 by outputting a drive signal OUT to the switching element 15 in accordance with the control signal OUTOFF from the input buffer 120. The switching circuit 170 adjusts the drive current supplied to the control terminal G when driving the control terminal G according to the control voltage IDREF.

[0030] Figure 2 shows the configuration of the temperature detection circuit 130 according to this embodiment. The temperature detection circuit 130 includes one or more comparators 200-1 to 2 (also referred to as "comparator 200"), one or more timers 210-1 to 2 (also referred to as "timer 210"), a decoder 220, and other circuit elements. A constant current source connected between the power supply voltage VCC and the temperature sensor 40 ("detected value OT" in the figure) supplies a constant current to the temperature sensor 40. As a result, the temperature sensor 40 generates a voltage corresponding to the temperature of the switching element 15 as the detected value OT. A smoothing filter such as an RC integrator smooths the detected value OT.

[0031] One or more comparators 200 classify the detected value OT into a plurality of voltage ranges. In the example of this figure, comparators 200-1 to 2 classify the detected value OT into below the voltage threshold VROTH (temperature ≧ T2), exceeding the voltage threshold VROTH and below the voltage threshold VROTM (T1 ≦ temperature < T2), and exceeding the voltage threshold VROTM (temperature < T1), and output signals OTHEN and OTMEN indicating the classification results. The decoder 220 decodes the signals OTHEN and OTMEN and outputs them as temperature detection signals TL / TM / TH that classify the temperature of the switching element 15 into a plurality of temperature ranges.

[0032] FIG. 3 shows the relationship between the input to the temperature detection circuit 130 according to this embodiment and the temperature. In this embodiment, the temperature sensor 40 is realized by a thermal diode. Since the voltage drop of the thermal diode becomes smaller as the temperature rises, the temperature sensor 40 outputs a detected value OT of a lower voltage as the temperature of the switching element 15 rises. The voltage threshold VROTM in FIG. 2 is set to the voltage of the detected value OT when the temperature of the switching element 15 reaches the temperature threshold T1. The voltage threshold VROTH in FIG. 2 is set to the voltage of the detected value OT when the temperature of the switching element 15 reaches the temperature threshold T2 (T2 > T1).

[0033] FIG. 4 shows the input and output of the temperature detection circuit 130 according to this embodiment. Comparator 200-1 outputs a signal OTHEN that is logic 1 when the detected value OT is below the voltage threshold VR OT H (temperature ≧ T2), and logic 0 when exceeding the voltage threshold VR OT H (temperature < T2). Comparator 200-2 outputs a signal OTMEN that is logic 1 when the detected value OT is below the voltage threshold VR OT M (temperature ≧ T1), and logic 0 when exceeding the voltage threshold VR OT M (temperature < T1). The decoder 220 decodes such signals OTHEN and OTMEN so that the temperature detection signal TL is logic 1 when the temperature < T1, the temperature detection signal TM is logic 1 when T1 ≦ temperature < T2, and the temperature detection signal TH is logic 1 when T2 ≦ temperature.

[0034] FIG. 5 shows the configuration of the current detection circuit 140 according to the present embodiment. The current detection circuit 140 includes a sense resistor Rsens, a comparator 500, and a flip-flop 510. The sense resistor Rsens is connected between the sense terminal of the switching element 15 and the reference potential (ground potential in the example of this figure), and conducts a sense current proportional to the current flowing through the switching element 15. Thereby, the detection value OC becomes a voltage value corresponding to the current flowing through the switching element 15.

[0035] The comparator 500 compares the detection value OC with the threshold voltage VDVDT. The comparator 500 outputs a logic 1 when the detection value OC is less than the threshold voltage VDVDT (current flowing through the switching element 15 < I1) ILOW, and outputs a logic 0 when the detection value OC is greater than or equal to the threshold voltage VDVDT (current flowing through the switching element 15 ≧ I1). The signal output by the comparator 500 is an example of a current detection signal corresponding to the current flowing through the switching element 15.

[0036] The flip-flop 510 samples a current detection signal corresponding to the current flowing through the switching element 15 at the timing during the on-period of the switching element 15. In this figure, the flip-flop 510 latches the current detection signal at the timing when the control signal OUTOFF rises. Thereby, the flip-flop 510 can sample a current detection signal corresponding to the current flowing through the switching element 15 at the timing at the end of the steady state in which the switching element 15 is on. The flip-flop 510 outputs the sampled current detection signal as ILOW.

[0037] FIG. 6 shows the configuration of the voltage output circuit 160 according to the present embodiment. The voltage output circuit 160 includes a variable resistance circuit composed of a plurality of resistors R1 to 5 and a plurality of switches SW1 to 4, and a decoder circuit 600. The plurality of resistors R1 to 5 are connected in series between the power supply voltage VDD and the reference potential (ground potential in the example of this figure), and divide the power supply voltage VDD. Each of the plurality of switches SW1 to 4 is connected between each of the plurality of resistors R1 to 5 and the output of the voltage output circuit 160. The decoder circuit 600 decodes the temperature detection signals TL / TM / TH and the current detection signal ILOW, and outputs a signal for turning on and off each of the switches SW1 to 4.

[0038] FIG. 7 shows the input and output of the voltage output circuit 160 according to the present embodiment. When the temperature detection signal TH = 1 (logical 1) (when the temperature ≥ T2), the decoder circuit 600 turns on the switch SW1 in FIG. 6. At this time, the decoder circuit 600 turns off the switches SW2 to 4. Thereby, the voltage output circuit 160 outputs the voltage V1 between the resistors R1 and R2 as the control voltage IDREF.

[0039] When the temperature detection signal TM = 1 (when T1 ≤ temperature < T2), the decoder circuit 600 turns on the switch SW2 in FIG. 6. At this time, the decoder circuit 600 turns off the switches SW1, 3, and 4. Thereby, the voltage output circuit 160 outputs the voltage V2 (<V1) between the resistors R2 and R3 as the control voltage IDREF.

[0040] When the temperature detection signal TL = 1 and the current detection signal ILOW = 0 (when the temperature < T1 and the current indicated by the current detection signal ILOW ≥ I1), the decoder circuit 600 turns on the switch SW3 in FIG. 6. At this time, the decoder circuit 600 turns off the switches SW1, 2, and 4. Thereby, the voltage output circuit 160 outputs the voltage V3 (<V2) between the resistors R3 and R4 as the control voltage IDREF.

[0041] When the temperature detection signal TL = 1 and the current detection signal ILOW = 1 (when the temperature < T1 and the current indicated by the current detection signal ILOW < I1), the decoder circuit 600 turns on the switch SW4 in FIG. 6. At this time, the decoder circuit 600 turns off the switches SW1 to SW3. Thereby, the voltage output circuit 160 outputs the voltage V4 (< V3) between the resistors R4 and R5 as the control voltage IDREF.

[0042] FIG. 8 shows the configuration of the switching circuit 170 according to the present embodiment. The switching circuit 170 includes a MOSFET 800, a MOSFET 810, a MOSFET 820, a MOSFET 830, a resistor 840, a differential amplifier circuit 850, and a MOSFET 860. The MOSFETs 800 and 810 function as a current mirror circuit that outputs a drive current i1 × a obtained by amplifying the current i1 (the current between the drain and source of the MOSFET 800) supplied to the MOSFET 800 by a factor of a to the control terminal G of the switching element 15. The source of the MOSFET 800 is connected to the power supply voltage VCC, and the gate and drain are connected. The source of the MOSFET 810 is connected to the power supply voltage VCC, the gate is connected to the gate of the MOSFET 800, and the drain is connected to the control terminal G of the switching element 15 as the output of the switching circuit 170.

[0043] The MOSFET 820 is connected in series with the MOSFET 810 between the power supply voltage VCC and the reference potential PGND (the emitter potential of the switching element 15), and the control signal OUTOFF from the input buffer 120 is input to the gate. The MOSFET 820 turns off when the control signal OUTOFF is 0. In this case, the MOSFET 810 outputs the drive current to the control terminal G of the switching element 15. The MOSFET 820 turns on when the control signal OUTOFF is 1, connects the control terminal G of the switching element 15 to the reference potential PGND, and turns off the switching element 15.

[0044] MOSFET 830, resistor 840, and differential amplifier circuit 850 are a current control circuit that supplies a current corresponding to the control voltage IDREF from the voltage output circuit 160 to the current mirror circuit of MOSFET 800 and MOSFET 810. MOSFET 830 and resistor 840 are connected in series between the drain of MOSFET 800 and the reference potential PGND. The differential amplifier circuit 850 receives the control voltage IDREF as input to its positive terminal and the voltage between MOSFET 830 and resistor 840 as input to its negative terminal. The output terminal of the differential amplifier circuit 850 is connected to the gate of MOSFET 830. When the control signal OUTOFF is 0, the differential amplifier circuit 850 controls MOSFET 830 so that the potential between MOSFET 830 and resistor 840 becomes the potential of the control voltage IDREF. As a result, when the control signal OUTOFF is 0, resistor 840 supplies a current i1, which is the current value obtained by dividing the control voltage IDREF by the resistance value of resistor 840, through the path of MOSFET 800, MOSFET 830, and resistor 840.

[0045] MOSFET860 is connected between the gate of MOSFET830 and the reference potential PGND, and the control signal OUTOFF is input to its gate. MOSFET860 is off when the control signal OUTOFF is 0. MOSFET860 is on when the control signal OUTOFF is 1, forcing MOSFET830 off and preventing current from flowing to MOSFET800 (current i1=0).

[0046] The switching circuit 170 described above can turn on the switching element 15 when the control voltage OUTOFF is 0 by supplying a drive current, which is amplified by the current mirror circuit according to the control voltage IDREF, to the switching element 15. Also, when the control voltage OUTOFF is 1, the switching element 15 can be turned off by setting the control terminal G of the switching element 15 to the reference potential PGND.

[0047] FIG. 9 shows the noise reduction effect in the low current region of the device 5 according to the present embodiment when the temperature is <T1>. When the temperature detection signal TL from the temperature detection circuit 130 is logic 1 and TM and TH are both logic 0, the drive circuit 150 reduces the drive current according to the current detection signal ILOW indicating that the main current flowing through the switching element 15 is smaller.

[0048] More specifically, when the current detection signal ILOW sampled during the on-period of the switching element 15 is 0, the switching element 15 conducts a current of I1 or more during the on-period (in the figure, medium and large current regions). When the current detection signal ILOW is 1, the switching element 15 conducts a current of less than I1 during the on-period (in the figure, low current region). When the driving device 100 is used in the low current region where the switching element 15 conducts a current of less than I1 during the on-period, the driving device 100 reduces the driving current supplied to the switching element 15 by reducing the control voltage IDREF from voltage V3 to V4.

[0049] In this way, when the switching element 15 is used in the low current region, the driving device 100 reduces the switching speed dv / dt of the switching element 15 compared to when it is used in the medium and large current regions. Thereby, the driving device 100 can reduce noise compared to the case where the switching speed of the switching element 15 is not reduced (dashed line in the figure).

[0050] FIG. 10 shows the loss reduction effect in the medium and large current regions of the device 5 according to the present embodiment when the temperature is <T1>. When the temperature is <T1>, the drive circuit 150 sets the control voltage IDREF to voltage V4 when the switching element 15 is used in the low current region where it conducts a current of less than I1 during the on-period. Here, when the drive current is the same, the switching loss Eon of the switching element 15 becomes larger when it is used in the medium and large current regions where it conducts a current of I1 or more during the on-period compared to when it is used in the low current region.

[0051] In this embodiment, when the driving circuit 150 is used in a medium-to-high current region where a current of I1 or more flows during the on-period of the switching element 15, the control voltage IDREF is set to the voltage V3, and the driving current supplied to the switching element 15 is increased. Thereby, the driving circuit 150 can reduce the switching loss of the switching element 15.

[0052] FIG. 11 shows the switching speed according to the temperature of the device 5 according to this embodiment. As the temperature of the switching element 15 rises, the switching speed dv / dt decreases, and accordingly, the noise decreases (dashed line in the figure). In this embodiment, the driving circuit 150 increases the control voltage IDREF from V3 or V4 to V2 to increase the driving current of the switching element 15 at the point where the detected value OT of the temperature sensor 40 switches from a state exceeding the threshold value VROTM to below the threshold value VROTM (the point where the temperature switches from <T1 (TL = 1) to the temperature ≧ T1 (TM = 1)). Further, the driving circuit 150 increases the control voltage IDREF from V2 to V1 to increase the driving current of the switching element 15 at the point where the detected value OT of the temperature sensor 40 switches from a state exceeding the threshold value VROTH to below the threshold value VROTH (the point where the temperature switches from <T2 (TM = 1) to the temperature ≧ T2 (TH = 1)).

[0053] In this way, when the current detection signal ILOW is the same, the driving circuit 150 reduces the driving current according to the temperature detection signal TL / TM / TH indicating that the temperature of the switching element 15 is lower, and increases the driving current according to the temperature detection signal TL / TM / TH indicating that the temperature of the switching element 15 is higher. Accordingly, the driving circuit 150 suppresses the decrease in the switching speed dv / dt of the switching element 15 accompanying the increase in temperature.

[0054] FIG. 12 shows the loss reduction effect according to the temperature of the device 5 according to the present embodiment. As the temperature of the switching element 15 rises, the switching speed dv / dt decreases, and accordingly, the switching loss increases (dashed line in the figure). As shown in relation to FIG. 11, the drive circuit 150 increases the drive current according to the temperature detection signals TL / TM / TH and raises the switching speed dv / dt. Thereby, the drive circuit 150 can reduce the switching loss of the switching element 15 accompanying the rise in temperature. This indicates According to the temperature detection signals TL / TM / TH, the drive current is increased and the switching speed dv / dt is raised. Thereby, the drive circuit 150 can reduce the switching loss of the switching element 15 accompanying the rise in temperature.

[0055] The drive device 100 described above can appropriately reduce the switching loss and switching noise of the switching element 15 according to the temperature of the switching element 15 and the current flowing through the switching element 15 during the on-period, if parameters such as the threshold voltages VR OT H and VR OT M, and voltages V1 to V4 are appropriately set according to the purpose of use.

[0056] In the present embodiment, the drive device 100 can set the magnitude of the drive current to a magnitude associated with the first temperature range (for example, T1≤temperature<T2) regardless of the value of the current detection signal ILOW, according to the temperature indicated by the temperature detection signals TL / TM / TH being included in the first temperature range (for example, T1≤temperature<T2) among a plurality of temperature ranges (for example, temperature<T1, T1≤temperature<T2, temperature≥T2). Also, the drive device 100 can adjust the magnitude of the drive current according to the value of the current detection signal ILOW, according to the temperature indicated by the temperature detection signal being included in the second temperature range (for example, temperature<T1) among a plurality of temperature ranges. For example, in a usage environment where the temperature of the switching element 15 becomes equal to or higher than a specific temperature threshold in response to a relatively large current flowing through the switching element during the on-period, the number of types of the magnitude of the drive current can be reduced by setting the magnitude of the drive current regardless of the value of the current detection signal in at least one temperature range.

[0057] In the present embodiment, such a second temperature range is the temperature range with the lowest temperature (temperature < T1) among a plurality of temperature ranges, and the first temperature range is a temperature range other than the temperature range with the lowest temperature among the plurality of temperature ranges (T1 ≤ temperature < T2, temperature ≥ T2). For example, in a usage mode where the switching element 15 passes a relatively large current (current ≥ I1) during the on-period and the temperature ≥ T1, by controlling the magnitude of the drive current only in the temperature range with the lowest temperature according to the current detection signal ILOW, the types of the magnitude of the drive current can be reduced.

[0058] FIG. 13 shows the configuration of the voltage output circuit 1300 according to the first modification of the present embodiment. In this modification, instead of the voltage output circuit 160 in the device 5 of FIG. 1, the voltage output circuit 1300 is used. Since the other components in the device 5 are the same as those in FIGS. 1 to 5 and 8, the description will be omitted except for the following differences.

[0059] The voltage output circuit 1300 includes a variable resistance circuit composed of a plurality of resistors R1 to 7 and a plurality of switches SW1 to 6, and a decoder circuit 1310. The plurality of resistors R1 to 7 are connected in series between the power supply voltage VDD and the reference potential (ground potential in the example of this figure) to divide the power supply voltage VDD. Each of the plurality of switches SW1 to 6 is connected between each resistor of the plurality of resistors R1 to 7 and the output of the voltage output circuit 1300. The decoder circuit 1310 decodes the temperature detection signals TL / TM / TH and the current detection signal ILOW and outputs a signal for turning on and off each of the switches SW1 to 6.

[0060] FIG. 14 shows the input and output of the voltage output circuit 1300 according to the first modification of the present embodiment. In this modification, the voltage output circuit 1300 sets the control voltage IDREF to a magnitude associated with the combination of the temperature range including the temperature indicated by the temperature detection signals TL / TM / TH among a plurality of temperature ranges and the current range including the current value indicated by the current detection signal ILOW among a plurality of current ranges, and thereby sets the magnitude of the drive current of the switching element 15 to the magnitude associated with the combination of these temperature ranges and current ranges. As shown in this figure, the voltage output circuit 1300 may change the control voltage IDREF according to which of the plurality of current ranges the current value indicated by the current detection signal ILOW is included in all temperature ranges.

[0061] The decoder circuit 1310 in FIG. 13 turns on the switch SW1 and sets the control voltage IDREF to the voltage V1 if the current detection signal ILOW = 0 when the temperature detection signal TH = 1 (temperature ≥ T2), and turns on the switch SW2 and sets the control voltage IDREF to the voltage V2 if the current detection signal ILOW = 1. The decoder circuit 1310 turns on the switch SW3 and sets the control voltage IDREF to the voltage V3 if the current detection signal ILOW = 0 when the temperature detection signal TM = 1 (T1 ≤ temperature < T2), and turns on the switch SW4 and sets the control voltage IDREF to the voltage V4 if the current detection signal ILOW = 1. The decoder circuit 1310 turns on the switch SW5 and sets the control voltage IDREF to the voltage V5 if the current detection signal ILOW = 0 when the temperature detection signal TL = 1 (temperature < T1), and turns on the switch SW6 and sets the control voltage IDREF to the voltage V6 if the current detection signal ILOW = 1.

[0062] In this modification, the drive device 100 can set the magnitude of the drive current of the switching element 15 for each combination of the temperature range and the current range. Thereby, the drive device 100 can adjust the magnitude of the drive current more flexibly according to the temperature of the switching element 15 and the magnitude of the current flowing through the switching element 15 during the on-period.

[0063] Figure 15 shows the configuration of the device 1500 according to a second modified example of this embodiment. The device 1500 uses a drive circuit 1550 instead of the drive circuit 150 in Figure 1. Other components in the device 1500 that are denoted by the same reference numerals as in Figure 1 are the same as in Figures 1 to 5, so their description will be omitted below except for the differences.

[0064] The drive circuit 1550 includes a voltage output circuit 1560 and a switching circuit 1570. The voltage output circuit 1560 outputs a constant reference voltage IDREF. The switching circuit 1570 receives the reference voltage IDREF, temperature detection signals TL / TM / TH, and current detection signal ILOW as inputs. The switching circuit 1570 changes the switching speed of the switching element 15 by adjusting the drive current supplied to the control terminal G of the switching element 15 according to the temperature detection signals TL / TM / TH and the current detection signal ILOW.

[0065] Figure 16 shows the configuration of a switching circuit 1570 according to a second modified example of this embodiment. The switching circuit 1570 includes a MOSFET 800, a MOSFET 810, a MOSFET 820, a MOSFET 830, a variable resistor 1640, a differential amplifier circuit 850, a MOSFET 860, and a decoder circuit 1600. Similar to the MOSFET 800 and MOSFET 810 shown in Figure 8, the MOSFET 800 and MOSFET 810 function as current mirror circuits that output a drive current amplified from the current supplied to the MOSFET 800. The MOSFET 820 is the same as the MOSFET 820 in Figure 8.

[0066] MOSFET830, variable resistor1640, differential amplifier circuit850, and decoder circuit1600 constitute a current control circuit that supplies current corresponding to the temperature detection signal TL / TM / TH and the current detection signal ILOW to the current mirror circuit of MOSFET800 and MOSFET810. MOSFET830 and variable resistor1640 are connected in series between the drain of MOSFET800 and the reference potential PGND.

[0067] The variable resistor 1640 includes multiple resistors R1-4 and multiple switches SW1-4. The multiple resistors R1-4 are connected in series between the reference potential (ground potential in this example) and the source of the MOSFET 830, dividing the source voltage of the MOSFET 830. Each of the multiple switches SW1-4 is connected between the MOSFET 830 side of each of the multiple resistors R1-4 and the negative terminal of the differential amplifier circuit 850.

[0068] The differential amplifier circuit 850 receives a reference voltage IDREF at its positive terminal. The differential amplifier circuit 850 also receives a voltage selected by switches SW1 to SW4 from among several voltages V1 to V4, obtained by dividing the source voltage of MOSFET 830 through several resistors R1 to R4, at its negative terminal. The output terminal of the differential amplifier circuit 850 is connected to the gate of MOSFET 830.

[0069] The decoder circuit 1600 decodes the temperature detection signals TL / TM / TH and the current detection signal ILOW and outputs signals to turn switches SW1 to SW4 on and off. The operation of the decoder circuit 1600 is the same as that of the decoder circuit 600 shown in Figures 6 to 7. When the temperature detection signal TH=1 (logic 1) (temperature ≥ T2), the decoder circuit 1600 turns on switch SW1 in Figure 16. At this time, the decoder circuit 1600 turns off switches SW2 to SW4. As a result, the variable resistor 1640 supplies the voltage V1 between resistors R1 and R2 as a feedback voltage IVD to the negative terminal of the differential amplifier circuit 850. In this case, the differential amplifier circuit 850 controls MOSFET 830 so that the voltage V1 becomes the reference voltage IDREF. As a result, the current control circuit supplies the current IDREF / R1 to the current mirror circuit.

[0070] When the temperature detection signal TM = 1 (when T1 ≤ temperature < T2), the decoder circuit 1600 turns on the switch SW2 in FIG. 16. At this time, the decoder circuit 1600 turns off the switches SW1, 3, and 4. As a result, the variable resistor 1640 supplies the voltage V2 between the resistors R2 and R3 as the feedback voltage IVD to the negative terminal of the differential amplifier circuit 850. In this case, the differential amplifier circuit 850 controls the MOSFET 830 so that the voltage V2 becomes the reference voltage IDREF. As a result, the current control circuit supplies the current IDREF / (R1 + R2) to the current mirror circuit.

[0071] When the temperature detection signal TL = 1 (when temperature < T1) and the current detection signal ILOW = 0 (when current ≥ I1), the decoder circuit 1600 turns on the switch SW3 in FIG. 16. At this time, the decoder circuit 1600 turns off the switches SW1, 2, and 4. As a result, the variable resistor 1640 supplies the voltage V3 between the resistors R3 and R4 as the feedback voltage IVD to the negative terminal of the differential amplifier circuit 850. In this case, the differential amplifier circuit 850 controls the MOSFET 830 so that the voltage V3 becomes the reference voltage IDREF. As a result, the current control circuit supplies the current IDREF / (R1 + R2 + R3) to the current mirror circuit.

[0072] When the temperature detection signal TL = 1 (when temperature < T1) and the current detection signal ILOW = 1 (when current < I1), the decoder circuit 1600 turns on the switch SW4 in FIG. 16. At this time, the decoder circuit 1600 turns off the switches SW1 to 3. As a result, the variable resistor 1640 supplies the voltage V4 between the resistor R4 and the source of the MOSFET 830 as the feedback voltage IVD to the negative terminal of the differential amplifier circuit 850. In this case, the differential amplifier circuit 850 controls the MOSFET 830 so that the voltage V4 becomes the reference voltage IDREF. As a result, the current control circuit supplies the current IDREF / (R1 + R2 + R3 + R4) to the current mirror circuit. The MOSFET 860 is the same as the MOSFET 860 in FIG. 8.

[0073] According to the modified switching circuit 1570, instead of generating a control voltage IDREF corresponding to the temperature detection signal and current detection signal using the voltage output circuit 160, the drive current of the switching element 15 can be controlled according to the temperature detection signal and current detection signal by providing a variable resistor 1640 between the MOSFET 830 and the reference potential PGND.

[0074] Figure 17 shows the configuration of a switching circuit 1700 according to a third modified example of this embodiment. The switching circuit 1700 may be used in place of the switching circuit 1570 in Figure 15. Components in this figure that are denoted by the same reference numerals as in Figure 8 are the same as in Figure 8, so their explanation will be omitted below, except for the differences.

[0075] The switching circuit 1700 includes a MOSFET 800, a plurality of MOSFETs 810-1 to 4 (hereinafter also referred to as "MOSFET 810"), switches SW1a to 4a, switches SW1b to 4b, a MOSFET 820, a MOSFET 830, a resistor 840, a differential amplifier circuit 850, a MOSFET 860, and a decoder circuit 1710. The MOSFET 800, the plurality of MOSFETs 810-1 to 4, switches SW1a to 4a, and switches SW1b to 4b function as a current mirror circuit that outputs a drive current amplified from the current supplied to the MOSFET 800. The source of the MOSFET 800 is connected to the power supply voltage VCC, and the gate and drain are connected. Each of the MOSFETs 810-1 to 4 has its gate connected to the power supply voltage VCC via switches SW1b to 4b, its gate connected to the gate of the MOSFET 800 via switches SW1a to 4a, and its drain connected to the control terminal G of the switching element 15 as the output of the switching circuit 170. Switches SW1a to SW4a are turned on when each of signals D0 to SW3 is logic 1, and turned off when each of signals D0 to SW3 is logic 0. Switches SW1b to SW4b are turned on when each of signals D0 to SW3 is logic 0, and turned off when each of signals D0 to SW3 is logic 1.

[0076] Each MOSFET 810, when the corresponding signal among signals D0 to D3 is logic 1, amplifies the current flowing through MOSFET 800 and outputs it to the control terminal G of the switching element 15, similar to MOSFET 810 in Figure 8. Each MOSFET 810 turns off and does not supply current when the corresponding input among signals D0 to D3 is logic 0. As a result, the current amplification factor of the current mirror circuit containing multiple MOSFET 810s is variable according to the values ​​of signals D0 to D3.

[0077] MOSFET820, MOSFET830, resistor840, differential amplifier circuit850, and MOSFET860 are the same as the components with the same reference numerals in Figure 8. In this modified example, the differential amplifier circuit850 receives a constant voltage reference voltage IDREF as input.

[0078] The decoder circuit 1710 functions as an amplification factor setting circuit that sets the amplification factor of the current mirror circuit according to the temperature detection signal TL / TM / TH and the current detection signal ILOW. The decoder circuit 1710 decodes the temperature detection signal TL / TM / TH and the current detection signal ILOW and outputs signals D0 to 3 that turn switches SW1a to 4a and switches SW1b to 4b on or off, respectively.

[0079] Figure 18 shows the input and output of the decoder circuit 1710 according to a third modified example of this embodiment. When the temperature detection signal TH=1 (logic 1) (when temperature ≥ T2), the decoder circuit 1710 sets signals D0~3 to logic 1. As a result, switches SW1a~4a are turned on, switches SW1b~4b are turned off, and MOSFETs 810-1~4 amplify the current flowing through MOSFET 800. Therefore, the current amplification factor of the current mirror circuit is the sum of the current amplification factors of MOSFETs 810-1~4.

[0080] When the temperature detection signal TM = 1 (when T1 ≤ temperature < T2), the decoder circuit 1710 sets signals D0 to D2 to logic 1 and signal D3 to logic 0. As a result, switches SW1a to SW3a are on, switch SW4a is off, switches SW1b to SW3b are off, and switch SW4b is on, and MOSFETs 810-1 to 810-3 amplify the current flowing through MOSFET 800. Therefore, the current amplification factor of the current mirror circuit is the sum of the respective current amplification factors of MOSFETs 810-1 to 810-3.

[0081] When the temperature detection signal TL = 1 and the current detection signal ILOW = 0 (when temperature < T1 and the current indicated by the current detection signal ILOW ≥ I1), the decoder circuit 1710 sets signals D0 to D1 to logic 1 and signals D2 to D3 to logic 0. As a result, switches SW1a to SW2a are on, switches SW3a to SW4a are off, switches SW1b to SW2b are off, and switches SW3b to SW4b are on, and MOSFETs 810-1 to 810-2 amplify the current flowing through MOSFET 800. Therefore, the current amplification factor of the current mirror circuit is the sum of the respective current amplification factors of MOSFETs 810-1 to 810-2.

[0082] When the temperature detection signal TL = 1 and the current detection signal ILOW = 1 (when temperature < T1 and the current indicated by the current detection signal ILOW < I1), the decoder circuit 1710 sets signal D0 to logic 1 and signals D1 to D3 to logic 0. As a result, switch SW1a is on, switches SW2a to SW4a are off, switch SW1b is off, and switches SW2b to SW4b are on, and MOSFET 810-1 amplifies the current flowing through MOSFET 800. Therefore, the current amplification factor of the current mirror circuit is the same as the current amplification factor of MOSFET 810-1.

[0083] According to the modified switching circuit 1570, instead of generating a control voltage IDREF corresponding to the temperature detection signal and current detection signal using the voltage output circuit 160 in Figure 1, the drive current of the switching element 15 can be controlled according to the temperature detection signal and current detection signal by using a current mirror circuit including MOSFET 800 and multiple MOSFETs 810.

[0084] In the example shown in this figure, the decoder circuit 1710 always sets signal D0 to logic 1. When performing such control, the switching circuit 1700 may be configured such that it does not have switches SW1a~b and the gate of MOSFET810-1 is connected to the gate of MOSFET800. Also, the decoder circuit 1710 does not need to have a circuit portion that outputs signal D0.

[0085] Figure 19 shows the configuration of a voltage output circuit 1900 according to a fourth modification of this embodiment. In this modification, the voltage output circuit 1900 is used instead of the voltage output circuit 160 in the device 5 shown in Figures 1 and 6. The other components in the device 5 are the same as in Figures 1 to 5 and 8, so their explanation will be omitted below except for the differences.

[0086] The voltage output circuit 1900 in this modified example allows the control voltage IDREF output by the voltage output circuit 1900 in response to the temperature detection signal TL / TM / TH and the current detection signal ILOW to be preset by a predetermined trimming signal TR[7:0]. The trimming signal TR[7:0] may be input from outside the drive unit 100, or it may be set in a register or the like within the drive unit 100.

[0087] The voltage output circuit 1900 includes a variable resistor circuit consisting of multiple resistors R1 to R17, multiple selectors 1910-1 to R4 (also referred to as "selector 1910"), and multiple switches SW1 to R4, as well as a decoder circuit 1920. The multiple resistors R1 to R17 are connected in series between the power supply voltage VDD and the reference potential (ground potential in the example shown in this figure), dividing the power supply voltage VDD. Selector 1910-1 is connected between each resistor in resistors R1 to R5 and switches which of the voltages between each resistor in resistors R1 to R5 is output as voltage V1, according to the value of TR[7:6] in the trimming signal TR[7:0]. For example, selector 1910-1 may output the voltage between resistors R1 and R2 as voltage V1 when TR[7:6] = 0b00 (binary 0). Selector 1910-1 may output the voltage between resistors R2 and R3 as voltage V1 when TR[5:4]=0b01 (binary 1). Selector 1910-1 may output the voltage between resistors R3 and R4 as voltage V1 when TR[7:6]=0b10 (binary 2). Selector 1910-1 may output the voltage between resistors R4 and R5 as voltage V1 when TR[7:6]=0b11 (binary 0).

[0088] Selector 1910-2 is connected between each resistor R5 to R9 and switches which of the voltages between resistors R5 to R9 is output as voltage V2, according to the value of TR[5:4] in the trimming signal TR[7:0]. Selector 1910-3 is connected between each resistor R9 to R13 and switches which of the voltages between resistors R9 to R13 is output as voltage V3, according to the value of TR[3:2] in the trimming signal TR[7:0]. Selector 1910-4 is connected between each resistor R13 to R17 and switches which of the voltages between resistors R13 to R17 is output as voltage V4, according to the value of TR[1:0] in the trimming signal TR[7:0].

[0089] Each of the multiple switches SW1 to SW4 switches which of the multiple voltages V1 to SW4 to output as the control voltage IDREF. The decoder circuit 1920 decodes the temperature detection signals TL / TM / TH and the current detection signal ILOW and outputs signals to turn each of the switches SW1 to SW4 on or off. The input and output of the voltage output circuit 1900 are the same as the input and output of the voltage output circuit 160 shown in Figure 7.

[0090] According to the voltage output circuit 1900 of this modified example, the control voltage IDREF supplied to the switching circuit 170 in accordance with the temperature detection signal TL / TM / TH and the current detection signal ILOW can be adjusted after the drive unit 100 is manufactured.

[0091] In each of the embodiments and modifications described above, the drive unit 100 adjusts the magnitude of the drive current (the drive current flowing from the drive unit 100 to the control terminal G of the switching element 15) in the drive signal OUT supplied from the drive unit 100 to the switching element 15, according to the temperature detection signal and the current detection signal. Alternatively, or in addition to this, the drive unit 100 may also adjust the magnitude of the drive current (the drive current flowing from the control terminal G of the switching element 15 to the drive unit 100) in the drive signal OUT supplied from the drive unit 100 to the switching element 15, according to the temperature detection signal and the current detection signal.

[0092] Such a drive device 100 can be realized, for example, by replacing the MOSFET 820 in the switching circuit 170 in Figure 8 with an output stage MOSFET of a current mirror circuit that turns off when the control signal OUTOFF is 0, and when the control signal OUTOFF is 1, draws a drive current amplified according to the temperature detection signal and the current detection signal from the control terminal G of the switching element 15.

[0093] In each of the embodiments and modifications described above, the temperature detection signal indicates which of the three temperature ranges the temperature of the switching element 15 falls within. Alternatively, the temperature detection signal may indicate which of two or more arbitrary temperature ranges the temperature of the switching element 15 falls within, or it may indicate a continuous value corresponding to the temperature of the switching element 15. Also, in each of the embodiments and modifications described above, the current detection signal indicates which of two current ranges the current flowing through the switching element 15 during the ON period falls within. Alternatively, the current detection signal may indicate which of two or more arbitrary current ranges the current flowing through the switching element 15 during the ON period falls within, or it may indicate a continuous value corresponding to the current flowing through the switching element 15. The drive circuit 150 or drive circuit 1550 may adjust the magnitude of the drive current of the switching element 15 according to the possible combinations of values ​​of the temperature detection signal and the current detection signal.

[0094] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0095] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0096] 5 Device, 10 Driving element, 15 Switching element, 20 Main switching element, 30 Sense switching element, 40 Temperature sensor, 100 Driving device, 110 Power supply, 120 Input buffer, 130 Temperature detection circuit, 140 Current detection circuit, 150 Driving circuit, 160 Voltage output circuit, 170 Switching circuit, 200-1~2 Comparator, 210-1~2 Timer, 220 Decoder, 500 Comparator, 510 Flip-flop, 600 Decoder circuit, 800 MOSFET, 810-1~4 MOSFET, 820 MOSFET, 830 MOSFET, 840 Resistor, 850 Differential amplifier circuit, 860 MOSFET, 1300 Voltage output circuit, 1310 Decoder circuit, 1500 Device, 1550 Driving circuit, 1560 Voltage output circuit, 1570 Switching circuit, 1600 Decoder circuit, 1640 variable resistor, 1700 switching circuit, 1710 decoder circuit, 1900 voltage output circuit, 1910-1~4 selector, 1920 decoder circuit

Claims

1. A temperature detection circuit that outputs a temperature detection signal corresponding to the temperature of the switching element, A current detection circuit samples a current detection signal corresponding to the main current flowing through the switching element during the ON period of the switching element, A drive circuit that adjusts the drive current supplied to the control terminal of the switching element in accordance with the temperature detection signal and the current detection signal. Equipped with, The aforementioned drive circuit is In response to the temperature detection signal indicating a lower temperature of the switching element, the drive current is reduced compared to the case where the temperature detection signal indicating a higher temperature of the switching element is used. In response to the current detection signal indicating that the main current is smaller, the drive current is reduced compared to the case where the current detection signal indicating that the main current is larger. Drive unit.

2. The aforementioned drive circuit is The temperature indicated by the temperature detection signal is classified into one of several temperature ranges. In accordance with the fact that the temperature indicated by the temperature detection signal falls within the first temperature range among the plurality of temperature ranges, the magnitude of the drive current is set to a magnitude corresponding to the first temperature range, regardless of the value of the current detection signal. Depending on whether the temperature indicated by the temperature detection signal falls within a second temperature range that is lower than the first temperature range among the plurality of temperature ranges, the magnitude of the drive current is adjusted according to the value of the current detection signal. The drive device according to claim 1.

3. The drive device according to claim 2, wherein the second temperature range is the temperature range with the lowest temperature among the plurality of temperature ranges, and the first temperature range is a temperature range other than the temperature range with the lowest temperature among the plurality of temperature ranges.

4. The drive device according to claim 1, wherein the drive circuit sets the magnitude of the drive current to a magnitude corresponding to a combination of a temperature range among a plurality of temperature ranges that includes the temperature indicated by the temperature detection signal, and a current range among a plurality of current ranges that includes the current value indicated by the current detection signal.

5. The aforementioned drive circuit is A current mirror circuit that outputs the drive current which is an amplified version of the supplied current, A voltage output circuit that outputs a control voltage corresponding to the temperature detection signal and the current detection signal, A current control circuit that supplies a current corresponding to the control voltage to the current mirror circuit, A drive device according to any one of claims 1 to 4.

6. The aforementioned drive circuit is A current mirror circuit that outputs the drive current which is an amplified version of the supplied current, A current control circuit that supplies a current to the current mirror circuit corresponding to the temperature detection signal and the current detection signal. A drive device according to any one of claims 1 to 4.

7. The aforementioned drive circuit is A current mirror circuit that outputs the drive current which is an amplified version of the supplied current, An amplification factor setting circuit that sets the amplification factor of the current mirror circuit according to the temperature detection signal and the current detection signal. A drive device according to any one of claims 1 to 4.

8. The temperature detection circuit outputs a temperature detection signal corresponding to the temperature of the switching element, The current detection circuit outputs a current detection signal corresponding to the main current flowing through the switching element, The drive circuit adjusts the drive current supplied to the control terminal of the switching element according to the temperature detection signal and the current detection signal. Equipped with, The aforementioned drive circuit is In response to the temperature detection signal indicating a lower temperature of the switching element, the drive current is reduced compared to the case where the temperature detection signal indicating a higher temperature of the switching element is used. In response to the current detection signal indicating that the main current is smaller, the drive current is reduced compared to the case where the current detection signal indicating that the main current is larger. Driving method.

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