Temperature compensation circuit, semiconductor integrated circuit, semiconductor device, and temperature compensation method

Abstract

To provide a temperature compensation circuit suitable for appropriately protecting a power device from overcurrent.SOLUTION: According to one embodiment, there is provided a temperature compensation circuit having a correction circuit and a voltage supply circuit. The correction circuit has a first input node, a second input node, and an output node. The first input node is connected to a temperature sensor near a power device. The second input node is connected to a control terminal of the power device. The voltage supply circuit has an input node and an output node. The input node is connected to the output node of the correction circuit. The output node is connected to a second input node of a comparison circuit. The comparison circuit has a first input node and a second input node. The first input node is connected to one end of the power device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present embodiment relates to a temperature compensation circuit, a semiconductor integrated circuit, a semiconductor device, and a temperature compensation method. [Background technology]

[0002] A semiconductor device connected to a control terminal of a power device drives the power device. The power device is connected to a load that operates with a relatively large current and is used to switch the load. In the semiconductor device, it is desirable to appropriately protect the power device from overcurrent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2018 / 0097515 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one embodiment is to provide a temperature compensation circuit, a semiconductor integrated circuit, and a temperature compensation method suitable for appropriately protecting a power device from an overcurrent. [Means for solving the problem]

[0005] According to one embodiment, there is provided a temperature compensation circuit having a correction circuit and a voltage supply circuit. The correction circuit has a first input node, a second input node, and an output node. The first input node is connected to a temperature sensor near a power device. The second input node is connected to a control terminal of the power device. The voltage supply circuit has an input node and an output node. The input node is connected to an output node of the correction circuit. The output node is connected to a second input node of the comparison circuit. The comparison circuit has a first input node and a second input node. The first input node is connected to one end of the power device. [Brief description of the drawings]

[0006] [Figure 1] 1 is a circuit diagram showing a configuration of a semiconductor device according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining DESAT in the embodiment. [Diagram 3] FIG. 2 is a circuit diagram showing a configuration of a temperature sensor according to the embodiment. [Figure 4] FIG. 2 is a circuit diagram showing a configuration of a temperature compensation circuit according to an embodiment. [Diagram 5] FIG. 4 is a sequence diagram showing an operation of the temperature compensation circuit according to the embodiment. [Figure 6] 5 is a waveform diagram showing the operation of the semiconductor device according to the embodiment. [Figure 7] 5A to 5C are diagrams illustrating the operation of a temperature compensation circuit according to an embodiment. [Figure 8] FIG. 11 is a diagram showing the configuration of a temperature sensor according to a first modified example of the embodiment. [Figure 9] FIG. 11 is a circuit diagram showing a configuration of a temperature compensation circuit according to a second modified example of the embodiment. [Figure 10] FIG. 11 is a sequence diagram showing an operation of a temperature compensation circuit according to a second modified example of the embodiment. [Figure 11] FIG. 11 is a diagram showing a data structure of correction information according to a second modified example of the embodiment. [Figure 12] FIG. 13 is a diagram showing the operation of a correction circuit according to a third modified example of the embodiment. [Figure 13] FIG. 13 is a diagram showing the operation of a correction circuit according to a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a semiconductor device according to an embodiment will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment.

[0008] (Embodiment) The semiconductor device according to the embodiment is connected to a control terminal of a power device to drive the power device, and is designed to appropriately protect the power device from an overcurrent.

[0009] The semiconductor device 1 may be connected to a control terminal G of a power device PT as shown in Fig. 1 to drive the power device PT. Fig. 1 is a circuit diagram showing the configuration of the semiconductor device 1.

[0010] The power device PT is connected to a load LD that operates with a relatively large current, and is used to switch the load LD. The load LD may be a part of a DC motor and its drive circuit (e.g., an H-bridge circuit), and the power device PT may be another part of the drive circuit. Alternatively, the load LD may be a part of an AC motor and its drive circuit (e.g., an inverter circuit), and the power device PT may be another part of the drive circuit.

[0011] The power device PT may be any device capable of handling a relatively large current. The power device PT may be an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or a bipolar transistor. The substrate used in the element structure of the power device PT may be a SiC substrate or a Si substrate.

[0012] When a fault such as a short circuit occurs in the load LD, an overcurrent may flow through the power device PT. In order to protect the power device PT from an overcurrent, it is effective to detect when an overcurrent starts to flow through the power device PT and perform a protective operation to turn off the power device PT accordingly. The start of an overcurrent flowing through the power device PT can be detected by detecting DESAT (hereinafter referred to as DESAT detection).

[0013] DESAT can be defined as shown in Figure 2. Figure 2 is a diagram for explaining DESAT.

[0014] For example, when the power device PT is an N-type IGBT, one end of the power device PT is a collector C, the other end is an emitter E, and the control terminal is a gate G, as shown in FIG. 2(a).

[0015] As shown in Figure 2(b), the power device PT operates with a voltage V between the gate G and emitter E. CE When the voltage V between the collector C and the emitter E exceeds a certain value and turns on, in the region RG1, CE As the current I flows from collector C to emitter E, C In the higher voltage region RG2, the voltage V CE With increasing current I C will increase gradually.

[0016] As shown by the white arrow in Figure 2(b), the current I C The current I C The transition to the region RG2, where the transition is gradual, is called DESAT. Region RG1 is sometimes called the saturation region. Region RG2 is sometimes called the active region.

[0017] In addition, when the power device PT is a P-type IGBT, the polarity of the voltage between the gate G and emitter E that is turned on is reversed, and the collector current flows in the direction from the emitter E to the collector C, except that the power device PT is the same as when it is an N-type IGBT.

[0018] Alternatively, when the power device PT is an N-type power MOSFET, one end of the power device PT is a drain D, the other end is a source S, and the control terminal is a gate G, as shown in FIG. 2(c).

[0019] As shown in Figure 2(d), the power device PT has a gate G-source S voltage V GS When the voltage V between the drain D and source S exceeds a certain value and turns on, in the region RG11,DS As the current I of the drain D increases D In the higher voltage region RG12, the current I D will increase gradually.

[0020] As shown by the white arrow in Fig. 2(d), the current I D The current I D The transition to the region RG12 where the slope is gentle is called DESAT. The region RG11 is sometimes called the linear region. The region RG12 is sometimes called the saturation region.

[0021] When the power device PT is a P-type power MOSFET, the polarity of the voltage between the gate G and source S that is turned on is reversed, and the drain current flows in the direction from the source S to the drain D. Except for this, the power device PT is the same as when it is an N-type power MOSFET.

[0022] Although not shown, if the power device PT is a bipolar transistor, one end of the power device PT is the collector, the other end is the emitter, and the control terminal is the base. The transition from the region where the current at both ends is steep to the region where the current at both ends is gentle is called DESAT.

[0023] The following explanation focuses on the case where the power device PT is an N-type power MOSFET. One end, the other end, and the control terminal of the power device PT are represented by D, S, and G, respectively. The following explanation can also be applied to cases where the power device PT is of other types.

[0024] The semiconductor device 1 shown in Fig. 1 has input nodes 1a to 1e and an output node 1f. The node 1a is connected to the outside (for example, a higher-level controller) and receives an input signal IN from the outside. The input node 1b is connected to one end D of the power transistor PT and one end of the load LD. The input node 1c is connected to a control terminal G of the power transistor PT. The input nodes 1d and 1e are connected to one end and the other end of the temperature sensor TS, respectively. The output node 1f is connected to the control terminal G of the power transistor PT.

[0025] The power device PT has one end D connected to the input node 1b of the semiconductor device 1 and one end of the load LD, the other end S connected to a ground potential, and a control terminal G connected to the input node 1c and the output node 1e of the semiconductor device 1. The power device PT may include a rectifying element (e.g., a diode) whose forward direction is from the other end S to the one end D.

[0026] At least a part of the temperature sensor TS is disposed in the vicinity of the power device PT and is capable of detecting the temperature of the power device PT. The temperature sensor TS outputs the detection result to the input nodes 1d and 1e.

[0027] The semiconductor device 1 includes a semiconductor integrated circuit 2 and a rectifier D DESAT , capacitance element C BLANK , resistor element R DESAT and resistive element R G has.

[0028] The semiconductor integrated circuit 2 may be configured as a single chip, or may be configured by dividing it into multiple chips. The semiconductor integrated circuit 2 is provided with a terminal IN, a terminal DESAT, a terminal DRV, a terminal GATE, a terminal TEMP, and a terminal GND. The terminal GND is connected to the ground potential.

[0029] Rectifier D DESAT is connected between the terminal DESAT and one end D of the power device PT. DESAT The direction from the terminal DESAT to the terminal D is the forward direction. DESATmay be a diode.

[0030] Capacitive element C BLANK One end is connected to the terminal DESAT and the rectifier element D DESAT and the other end is connected to the ground potential. BLANK The capacitance value of the capacitance element C can be determined in advance according to the operating characteristics required for the protection circuit 3. BLANK The capacitance value of the capacitance element C required for DESAT detection of the power device PT is BLANK may be predetermined depending on the charging characteristics of the current source 32 (eg, the RC time constant or the charging time by the current source 32).

[0031] Resistance element R DESAT terminal DESAT and rectifier element D DESAT A resistor element R DESAT The resistance value of the resistor element R can be determined in advance according to the operating characteristics required for the protection circuit 3. DESAT The resistance value of the capacitance element C required for DESAT detection of the power device PT BLANK This can be predetermined depending on the charging characteristics (eg, RC time constant) of the battery.

[0032] Resistance element R G is connected between the terminal DRV and the control terminal G of the power device PT. G The resistance value can be determined in advance according to the operating characteristics (eg, drive capability) required for the drive circuit 5.

[0033] The semiconductor integrated circuit 2 includes a protection circuit 3, a temperature compensation circuit 4, and a drive circuit 5.

[0034] The protection circuit 3 is connected between the drive circuit 5 and the terminal DESAT. When the protection circuit 3 detects the DESAT of the power device PT via the terminal DESAT, the protection circuit 3 supplies a signal Shutdown to the drive circuit 5 to instruct the drive circuit 5 to shut down the power device PT.

[0035] The protection circuit 3 includes a comparison circuit 31, a current source 32, a switch 33, a signal generation circuit 34, and a signal generation circuit 35. The comparison circuit 31 includes an input node 31a, an input node 31b, and an output node 31c. The input node 31a is connected to a terminal DESAT, a resistor element R DESAT , rectifier D DESAT The input node 31b is connected to one end D of the power transistor PT via a control signal . The input node 31b is connected to a part of the temperature compensation circuit 4. For example, a variable voltage source 422 described later is connected to the input node 31b. The variable voltage source 422 generates a threshold voltage Vth in response to a control signal Threshold and supplies it to the input node 31b. The output node 31c is connected to the signal generating circuit .

[0036] For example, the comparator circuit 31 detects the voltage V DESAT is compared with the threshold voltage Vth.

[0037] When input node 31a is a non-inverting input node and input node 31b is an inverting input node, comparison circuit 31 detects a voltage V DESAT If is higher than the threshold voltage Vth, the comparison result of the H level is output, and the voltage V DESAT If is lower than the threshold voltage Vth, the comparison result is output at L level.

[0038] When input node 31a is an inverting input node and input node 31b is a non-inverting input node, comparison circuit 31 detects a voltage V DESAT is higher than the threshold voltage Vth, the comparison result is output at L level, and the voltage V DESAT If is lower than the threshold voltage Vth, the comparison result is output as H level.

[0039] The current source 32 has one end connected to a power supply potential and the other end connected to a node between the input node 31a of the comparison circuit 31 and the terminal DESAT. The current source 32 may be a constant current source, and supplies a constant current to the capacitive element C via the terminal DESAT. BLANKThe constant current supplied by the current source 32 can be determined in advance according to the operating characteristics required for the protection circuit 3. The constant current supplied by the current source 32 can be determined in advance according to the operating characteristics required for the protection circuit 3. BLANK This can be predetermined depending on the charging characteristics (eg, RC time constant) of the battery.

[0040] The switch 33 is a capacitance element C BLANK and the ground potential. One end of the switch 33 is connected to a node between the input node 31a of the comparison circuit 31 and the terminal DESAT, the other end is connected to the ground potential, and a control terminal is connected to the signal generation circuit 35.

[0041] When the switch 33 receives a control signal MASK of a non-active level (for example, an L level) from the signal generating circuit 35, the switch 33 is turned off to BLANK One end of the capacitance element C is cut off from the ground potential. BLANK When the switch 33 receives an active level (for example, H level) control signal MASK from the signal generating circuit 35, the switch 33 turns on to charge the capacitance element C BLANK One end of the capacitance element C is connected to the ground potential. BLANK The charge is extracted from one end and discharged to the ground potential.

[0042] The signal generating circuit 34 is connected between the comparator circuit 31 and the drive circuit 5. The signal generating circuit 34 generates a control signal Shutdown for shutting down the drive circuit 5 in response to an inversion of the comparison result of the comparator circuit 31, and supplies the control signal Shutdown to the drive circuit 5.

[0043] When the input node 31a of the comparison circuit 31 is a non-inverting input node and the input node 31b is an inverting input node, the signal generation circuit 34 supplies a non-active level control signal Shutdown to the drive circuit 5 during a period TP1 when the comparison circuit 31 outputs an L level comparison result. The signal generation circuit 34 supplies an active level control signal Shutdown to the drive circuit 5 during a period TP2 when the comparison circuit 31 outputs an H level comparison result.

[0044] When the input node 31a of the comparison circuit 31 is an inverting input node and the input node 31b is a non-inverting input node, the signal generation circuit 34 supplies a non-active level control signal Shutdown to the protection circuit 3 during a period TP11 when the comparison circuit 31 outputs an H level comparison result. The signal generation circuit 34 supplies an active level control signal Shutdown to the drive circuit 5 during a period TP12 when the comparison circuit 31 outputs an L level comparison result.

[0045] The signal generating circuit 35 is connected between the terminal IN and the switch 33. The signal generating circuit 35 generates a control signal MASK in response to the input signal IN, and supplies the control signal MASK to the switch 33.

[0046] The driving circuit 5 has an input node 5a, an output node 5b, and a control node 5c. The input node 5a is connected to a terminal IN. The output node 5b is connected to a terminal DRV and a resistive element R G The control node 5c is connected to the control terminal G of the power transistor PT via the protection circuit 3.

[0047] The drive circuit 5 is connected between the terminal IN and the terminal DRV. While the drive circuit 5 receives the control signal Shutdown at a non-active level, the drive circuit 5 generates a drive signal DRV for switching in response to the input signal IN and supplies the drive signal DRV to the control terminal G of the power transistor PT. This allows the switching of the power transistor PT to be controlled.

[0048] When the drive circuit 5 receives the active-level control signal Shutdown, it generates a drive signal DRV to maintain the power transistor PT in the off state regardless of the input signal IN, and supplies the drive signal DRV to the control terminal G of the power transistor PT. This maintains the power transistor PT in the off state. This allows the power transistor PT to be protected from an overcurrent generated in the load LD.

[0049] The temperature compensation circuit 4 is connected between the terminals GATE and TEMP and the protection circuit 3. The temperature compensation circuit 4 has a correction circuit 41 and a voltage supply circuit 42. The correction circuit 41 is disposed between the terminals GATE and TEMP and the voltage supply circuit 42. The voltage supply circuit 42 is disposed between the correction circuit 41 and the protection circuit 3.

[0050] The correction circuit 41 is a circuit for calculating the temperature of the power device PT and the voltage V G The voltage supply circuit 42 generates a correction signal according to the correction signal. The voltage supply circuit 42 corrects the threshold voltage Vth according to the correction signal. The voltage supply circuit 42 supplies the corrected threshold voltage Vth to the input node 31b of the comparison circuit 31.

[0051] The correction circuit 41 has an input node 41a, an input node 41b, and an output node 41c. The input node 41a is connected to the temperature sensor TS via a terminal TEMP. One end of a current source 7 may be connected between the input node 41a and the terminal TEMP. The other end of the current source 7 may be connected to a power supply potential. The input node 41b is connected to a control terminal G of the power transistor PT via a terminal GATE. The output node 41c is connected to a voltage supply circuit 42.

[0052] The correction circuit 41 has a temperature acquisition circuit 411, a voltage acquisition circuit 412, and a correction processing circuit 413. The temperature acquisition circuit 411 is connected between a terminal TEMP and the correction processing circuit 413. The voltage acquisition circuit 412 is connected between a terminal GATE and the correction processing circuit 413. The correction processing circuit 413 is connected between the temperature acquisition circuit 411, the voltage acquisition circuit 412, and the voltage supply circuit 42.

[0053] In the correction circuit 41, the temperature acquisition circuit 411 acquires a signal indicating the temperature of the power device PT from the temperature sensor TS via the terminal TEMP and the input node 41a. The temperature acquisition circuit 411 converts the signal format into a format that can be processed by the correction processing circuit 413, and supplies the converted signal to the correction processing circuit 413.

[0054] The voltage acquisition circuit 412 acquires a signal indicating the voltage of the control terminal G from the control terminal G of the power device PT via the terminal GATE and the input node 41b. The voltage acquisition circuit 412 converts the signal format into a format processable by the correction processing circuit 413, and supplies the converted signal to the correction processing circuit 413.

[0055] The correction circuit 41 receives a signal from a temperature acquisition circuit 411 and a signal from a voltage acquisition circuit 412. The correction circuit 41 generates a correction signal according to the temperature of the power device PT and the voltage of the control terminal G, and supplies the correction signal to the voltage supply circuit 42 via an output node 41c.

[0056] The voltage supply circuit 42 has an input node 42a and an output node 42b. The input node 42a is connected to the correction circuit 41. The output node 42b is connected to the input node 31b of the comparison circuit 31.

[0057] The voltage supply circuit 42 has a control circuit 421 and a variable voltage source 422. The control circuit 421 is connected between the correction processing circuit 413 and the variable voltage source 422. The variable voltage source 422 has one end connected to the input node 31b of the comparison circuit 31, the other end connected to the ground potential, and a control terminal connected to the control circuit 421.

[0058] In the voltage supply circuit 42, the control circuit 421 receives a correction signal from the correction circuit 41. The control circuit 421 corrects the threshold voltage Vth in response to the correction signal. The voltage supply circuit 42 generates a control signal Threshold indicating the corrected threshold voltage Vth and supplies it to a control node of the variable voltage source 422. The variable voltage source 422 adjusts the voltage it generates in response to the control signal Threshold, and supplies the adjusted voltage to the input node 31b of the comparison circuit 31 as the threshold voltage Vth.

[0059] For example, when the temperature of the power device PT is a first temperature and the voltage of the control terminal G is a first voltage, the correction circuit 41 generates a first correction signal. The first correction signal includes an instruction to correct the threshold voltage to a first level. The first level may correspond to a rated current of the power device PT at the first temperature. The correction circuit 41 supplies the first correction signal to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the first level in response to the first correction signal.

[0060] Alternatively, when the temperature of the power device PT is a second temperature and the voltage of the control terminal G is a first voltage, the correction circuit 41 generates a second correction signal. The second temperature is higher than the first temperature. The second correction signal includes an instruction to correct the threshold voltage Vth to a second level. The second level is lower than the first level. The second level may correspond to a rated current of the power device at the second temperature. The correction circuit 41 supplies the second correction signal to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the second level in response to the second correction signal.

[0061] This makes it possible in the semiconductor device 1 to perform DESAT detection of the power device PT at the threshold voltage Vth according to the temperature and the voltage of the control terminal G while ensuring a current margin of the power device PT.

[0062] The configuration including the signal generating circuit 34, the signal generating circuit 35, and the control circuit 421 can be regarded as a DESAT processing circuit 6 that performs processing related to DESAT. The semiconductor integrated circuit 2 may further include a control circuit 8 that can supply control signals to the temperature acquiring circuit 411 and the voltage acquiring circuit 412, respectively.

[0063] Any temperature sensor capable of measuring temperature is used as the temperature sensor TS shown in Fig. 1. The temperature sensor TS may be configured as shown in Fig. 3. Fig. 3 is a circuit diagram showing the configuration of the temperature sensor TS.

[0064] The temperature sensor TS includes a sensor element SE and a filter circuit FC. The sensor element SE may be disposed in the vicinity of the power device PT. The sensor element SE includes a thermistor TH. The thermistor TH may be an NTC thermistor or a PTC thermistor. The resistance value of the thermistor TH changes depending on the temperature.

[0065] The filter circuit FC is connected between the sensor element SE and the semiconductor device 1. The filter circuit FC includes a resistor element R FL1 ,R FL2 , filter FL, capacitance element C FL The resistor element R FL1 One end of the resistor element R is connected to one end of the thermistor TH, and the other end of the resistor element R is connected to the other end of the thermistor TH. FL2 The filter FL has one end connected to the other end of the thermistor TH and the other end connected to the ground potential. FL and the resistive element R FL1 ,R FL2 The filter FL may be a low-pass filter. FL has one end connected to the input node 1d of the semiconductor device 1 and the P-side node of the filter FL, and the other end connected to the input node 1e of the semiconductor device 1 and the N-side node of the filter FL.

[0066] The filter circuit FC is capable of filtering the detection signal of the sensor element SE and supplying the processed detection signal to the semiconductor device 1. The filter circuit FC receives the voltage across the sensor element SE at a pair of input nodes, and outputs a pair of detection signals (a P-side detection signal and an N-type detection signal) corresponding to the voltage across the sensor element SE from a pair of output nodes to input nodes 1d and 1e.

[0067] In response to the change in the resistance value of the thermistor TH depending on the temperature, the thermistor TH and the resistive element R FL1 ,R FL2 The amount of current flowing into the resistor element R FL1 ,R FL2The voltage across the filter FL and the capacitance element C changes depending on the temperature. FL and transmitted as a pair of detection signals (P-side detection signal and N-type detection signal) to terminals TEMP and GND via input nodes 1d and 1e. The P-side detection signal flows to the temperature compensation circuit 4 via terminal TEMP, and the N-type detection signal flows to the ground potential via terminal GND.

[0068] The temperature compensation circuit 4 shown in Fig. 1 may be configured as shown in Fig. 4 and may operate as shown in Fig. 5. Fig. 4 is a circuit diagram showing the configuration of the temperature compensation circuit 4. Fig. 5 is a sequence diagram showing the operation of the temperature compensation circuit 4.

[0069] In the correction circuit 41 of the temperature compensation circuit 4, the temperature acquisition circuit 411 includes a variable amplifier AM1. The voltage acquisition circuit 412 includes a variable amplifier AM2. The correction processing circuit 413 includes an adder ADD, a switch SW1, and a capacitance element C1.

[0070] The variable amplifier AM1 has an input node connected to the temperature sensor TS and an output node connected to the adder ADD. The variable amplifier AM1 has a variable gain. The gain of the variable amplifier AM1 may be adjusted in advance under control of the control circuit 8 during calibration. The value of the adjusted gain may be determined experimentally in advance.

[0071] The variable amplifier AM1 acquires a signal indicating the temperature of the power device PT from the temperature sensor TS (S1). The variable amplifier AM1 amplifies the signal with its gain to convert the signal into a format that can be processed by the correction processing circuit 413, and supplies the converted signal AM1 to the correction processing circuit 413.

[0072] The variable amplifier AM2 has an input node connected to the control terminal G of the power device PT and an output node connected to the adder ADD via the switch SW. The variable amplifier AM2 has a variable gain. The gain of the variable amplifier AM2 may be adjusted in advance under control of the control circuit 8 during calibration. The value of the adjusted gain may be experimentally determined in advance.

[0073] The variable amplifier AM2 acquires a signal indicating the voltage of the control terminal G from the control terminal G of the power device PT (S2). The variable amplifier AM2 amplifies the signal with its gain, thereby converting the signal format into a format processable by the correction processing circuit 413, and supplies the converted signal AM2 to the correction processing circuit 413.

[0074] The switch SW1 has one end connected to the variable amplifier AM2 and the other end connected to one end of the capacitance element C1 and the adder ADD. The other end of the capacitance element C1 is connected to the ground potential.

[0075] The switch SW1 may be kept in an on state and an off state at a constant cycle. During the period in which the switch SW1 is kept in the on state, the signal AM2 amplified by the variable amplifier AM2 is sampled to the capacitance element C1, and during the period in which the switch SW1 is kept in the off state, the amplified signal AM2 is held by the capacitance element C1. As a result, the switched capacitor SC1 including the switch SW1 and the capacitance element C1 operates equivalently as a filter (S3), reducing noise in the signal AM2 amplified by the variable amplifier AM2 and generating a filtered signal AM2a.

[0076] The adder ADD receives the amplified signal AM1 from the variable amplifier AM1, receives the filtered signal AM2a from the switched capacitor SC1, and receives the signal offset from the control circuit 8. The signal offset can be determined experimentally in advance. The adder ADD adds the signals AM1, AM2a, and offset. That is, the adder ADD performs an operation to generate a correction signal ADD according to the signals AM1, AM2a, and offset (S4), and supplies the correction signal ADD to the voltage supply circuit 42.

[0077] In the voltage supply circuit 42, the control circuit 421 includes an amplifier AM3 and a switch SW2. The variable voltage source 422 includes a capacitance element C2.

[0078] The amplifier AM3 has an input node connected to the adder ADD and an output node connected to the switch SW2. One end of the switch SW2 is connected to the amplifier AM3 and the other end is connected to one end of the capacitance element C2. The other end of the capacitance element C2 is connected to the ground potential.

[0079] The amplifier AM3 receives the correction signal ADD from the adder ADD. The amplifier AM3 amplifies the correction signal ADD and supplies it to the switch SW2 side.

[0080] The switch SW2 may be maintained in an on state and an off state at a constant cycle. During the period when the switch SW2 is maintained in the on state, the signal AM3 amplified by the amplifier AM3 is sampled to the capacitive element C2, and during the period when the switch SW2 is maintained in the off state, the amplified signal AM3 is held by the capacitive element C2. That is, the signal AM3 corresponding to the correction signal ADD is held by the capacitive element C2 (S5). As a result, the switched capacitor SC2 including the switch SW2 and the capacitive element C2 operates equivalently as a filter, reducing noise in the signal AM3 amplified by the amplifier AM3, and generating a filtered signal AM3a. In response to this filtered signal AM3a, the capacitive element C2 generates a threshold voltage Vth across it and transmits it to the input node 31b of the comparator circuit 31. That is, the capacitive element C2 sets the threshold voltage Vth corresponding to the correction signal ADD to the input node 31b of the comparator circuit 31 (S6). In response to this, the protection circuit 3 including the comparison circuit 31 can perform DESAT detection using the threshold voltage Vth according to the correction signal ADD (S7).

[0081] Next, the time-series operation of the semiconductor device 1 will be described with reference to Fig. 6. Fig. 6 is a waveform diagram showing the operation of the semiconductor device 1.

[0082] Immediately before timing t1, the protection circuit 3 sets the control signal MASK to an active level and maintains the switch 33 in the on state, thereby disabling DESAT detection by the protection circuit 3.

[0083] At timing t1, when the rising edge of the waveform of the input signal INPUT is detected, the drive circuit 5 generates the drive signal V GATE_DRIVE to the active level.

[0084] At timing t2, the drive signal V GATE_DRIVE When the active level (e.g., H level) is reached, the voltage V G starts to rise, and the power device PT starts to turn on accordingly. In response, the current I D starts to flow, and the voltage V at one end D D begins to fall.

[0085] The protection circuit 3 sets the control signal MASK to a non-active level to turn off the switch 33. In response to this, the protection circuit 3 enables DESAT detection. That is, the protection circuit 3 becomes capable of detecting DESAT of the power device PT.

[0086] At time t3, the current I D When the voltage V at one end D stabilizes at a predetermined level, D falls to the reference level (for example, L level), and the transition of the power device PT to the ON state is completed.

[0087] During the period from timing t1 to t3, the voltage V DESAT may temporarily rise, but remains below the threshold voltage Vth. Therefore, the protection circuit 3 DESAT A temporary rise in the voltage is not detected as a DESAT.

[0088] At timing t4, an excessive current I flows to the power device PT in the on state due to a short circuit of the load LD. D When the current starts to flow in, the voltage V at one end D D begins to rise sharply, and accordingly, the voltage V at terminal DESAT DESAT also begins to rise rapidly.

[0089] At time t5, the voltage V of the terminal DESATDESAT exceeds the threshold voltage Vth, the comparison result of the comparison circuit 31 is inverted. That is, the protection circuit 3 detects the DESAT of the power device PT.

[0090] In response to this, at timing t6, the protection circuit 3 transitions the control signal Shutdown to an active level and supplies it to the drive circuit 5. DRV to a non-active level (for example, L level). In response to this, the power device PT starts to turn off and the current I D begins to decrease, and the voltage V at one end D D continues to rise.

[0091] At timing t7, the voltage V at one end D D reaches and remains at a predetermined level (for example, H level), and the drive signal V DRV falls to near a reference level (for example, L level). This causes the power device PT to be turned off.

[0092] At timing t8, the drive signal V GATE_DRIVE At timing t9, the current I D falls to the reference level, and the transition of the power device PT to the off state is completed.

[0093] Next, the operation of the temperature compensation circuit 4 will be described with reference to Fig. 7. Fig. 7 is a diagram showing the operation of the temperature compensation circuit 4.

[0094] In the temperature compensation circuit 4, a correction circuit 41 is configured to calculate the temperature T of the power device PT and the voltage V of the control terminal G. G The correction circuit 41 generates a correction signal according to the voltage V G A correction signal may be generated to instruct correction to the threshold voltage Vth corresponding to the rated current of the power device PT at the temperature T every time the power device PT is turned on.

[0095] For example, voltage V GWhen V = V1, the voltage V across the power transistor PT D and current I D The relationship between these two is as shown in Figure 7(a). If the temperature T = T1, it changes as shown by the solid line, if the temperature is higher, T = T2 (> T1), it changes on the lower current side as shown by the dashed line, and if the temperature is higher, T = T3 (> T2), it changes on the lower current side as shown by the dashed double dot line.

[0096] The rated current at temperatures T=T1, T2, and T3 is I D =I 11 ,I 12 ,I 13 The rated current can be said to be the upper limit of the allowable current at a given temperature. At temperatures T=T1, T2, and T3, the current I D =I 11 ,I 12 ,I 13 The voltage V D =V 11 ,V 12 ,V 13 may be the level of the threshold voltage to be corrected. 11 ,V 12 ,V 13 are in turn smaller.

[0097] The correction circuit 41 is G )=(T1,V1), the threshold voltage is set to level V 11 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 11 and supplies it to the input node 31 b of the comparison circuit 31 .

[0098] The correction circuit 41 is G )=(T2,V1), the threshold voltage is set to level V 12 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 12 and supplies it to the input node 31 b of the comparison circuit 31 .

[0099] The correction circuit 41 is G )=(T3,V1), the threshold voltage is set to the level V 13 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 13 and supplies it to the input node 31 b of the comparison circuit 31 .

[0100] Or, the voltage V G When V2 (> V1), the voltage VD and current I of the power transistor PT D The relationship between these two is as shown in Figure 7(b). At temperature T = T1, the change is as shown by the solid line, at a higher temperature T = T2 (> T1), the change is as shown by the dashed line on the lower current side, and at a higher temperature T = T3 (> T2), the change is as shown by the dashed double dot line on the lower current side.

[0101] The rated current at temperatures T=T1, T2, and T3 is I D =I 21 ,I 22 ,I 23 The rated current can be said to be the upper limit of the allowable current at a given temperature. At temperatures T=T1, T2, and T3, the current I D =I 21 ,I 22 ,I 23 The voltage V D =V 21 ,V 22 ,V 23 may be the level of the threshold voltage to be corrected. 21 ,V 22 ,V 23 are in turn smaller.

[0102] The correction circuit 41 is G )=(T1,V2), the threshold voltage is set to level V 21 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 21 and supplies it to the input node 31 b of the comparison circuit 31 .

[0103] The correction circuit 41 is G )=(T2,V2), the threshold voltage is set to level V 22 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 22 and supplies it to the input node 31 b of the comparison circuit 31 .

[0104] The correction circuit 41 is G )=(T3,V2), the threshold voltage is set to level V 23 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 23 and supplies it to the input node 31 b of the comparison circuit 31 .

[0105] In addition, when the temperature compensation circuit 4 is configured as shown in FIG. 4, the control circuit 8 may set the gain of the variable amplifier AM1 to correspond to the increase in the signal of the temperature T from T1 to T2 to T3, and the voltage V G A gain corresponding to increasing the signal from V1 to V2 may be set in the variable amplifier AM2.

[0106] As described above, in the embodiment, in the temperature compensation circuit 4 of the semiconductor device 1, the correction circuit 41 detects the temperature T of the power device PT and the voltage V of the control terminal G. G The voltage supply circuit 42 generates a correction signal according to the correction signal. The voltage supply circuit 42 corrects the threshold voltage Vth according to the correction signal. The voltage supply circuit 42 supplies the corrected threshold voltage Vth to the input node 31b of the comparison circuit 31. As a result, in the protection circuit 3 including the comparison circuit 31, G Therefore, DESAT detection can be performed using an appropriate threshold voltage Vth according to the above.

[0107] Also, in the embodiment, in the temperature compensation circuit 4 of the semiconductor device 1, the correction circuit 41 can generate a correction signal that instructs that the voltage of the control terminal G be corrected to a lower level as the temperature of the power device PT increases, provided that the voltage is the same. The voltage supply circuit 42 corrects the threshold voltage Vth to the instructed level in response to the correction signal. As a result, in the semiconductor device 1, the temperature T and the voltage V of the control terminal G can be adjusted while ensuring a current margin of the power device PT. G It is possible to perform DESAT detection of the power device PT at a threshold voltage Vth according to the above.

[0108] (First Modification of the Embodiment) The temperature sensor TS may be configured as shown in Fig. 8. Fig. 8 is a circuit diagram showing the configuration of the temperature sensor TSa in a first modified example of the embodiment.

[0109] The temperature sensor TSa includes a sensor element SEa and a filter circuit FCa. The sensor element SEa may be disposed in the vicinity of the power device PT. The sensor element SEa includes a diode D TS Includes diode D TS The forward voltage of a transistor varies depending on the temperature.

[0110] The filter circuit FC is connected between the sensor element SEa and the semiconductor device 1. The filter circuit FC includes a resistor element R TS and the capacitance element C TS The resistor element R TS One end of the diode D TS and the other end is connected to the input node 1d of the semiconductor device 1. TS has one end connected to the input node 1d of the semiconductor device 1 and the other end connected to the resistor element R TS The other end is connected to the input node 1e of the semiconductor device 1 and the diode D TS is connected to one end of the

[0111] The filter circuit FCa can filter the detection signal of the sensor element SEa and supply the processed detection signal to the semiconductor device 1. The filter circuit FCa receives the voltage across the sensor element SEa at a pair of input nodes, and outputs a pair of detection signals (a P-side detection signal and an N-type detection signal) corresponding to the voltage across the sensor element SEa from a pair of output nodes to input nodes 1d and 1e.

[0112] Diode D TS In response to the change in the forward voltage of the resistor R TS Via Diode D TS The voltage across both ends of changes. The voltage is smoothed by the filter FL and transmitted as a pair of detection signals (a P-side detection signal and an N-type detection signal) to the terminals TEMP and GND via the input nodes 1d and 1e. The P-side detection signal flows to the temperature compensation circuit 4 via the terminal TEMP, and the N-type detection signal flows to the ground potential via the terminal GND.

[0113] Such a temperature sensor TSa can also measure the temperature of the power device PT.

[0114] (Second Modification of the Embodiment) The temperature compensation circuit 4i may be configured as shown in Fig. 9 and may operate as shown in Fig. 10. Fig. 9 is a circuit diagram showing the configuration of the temperature compensation circuit 4i in a second modified example of the embodiment. Fig. 10 is a sequence diagram showing the operation of the temperature compensation circuit 4i.

[0115] In the correction circuit 41 of the temperature compensation circuit 4i, the temperature acquisition circuit 411 includes an AD conversion circuit AD1. The voltage acquisition circuit 412 includes an AD conversion circuit AD2. The correction processing circuit 413 includes an information conversion circuit CV. The information conversion circuit CV holds a correction information LUT. The correction information LUT is a relationship between the temperature T and the voltage V of the control terminal G. G and the threshold voltage Vth are temperature T and the voltage V G This is information associated with a plurality of combinations of the above.

[0116] The AD conversion circuit AD1 has an input node connected to the temperature sensor TS and an output node connected to the data conversion circuit CV.

[0117] The AD conversion circuit AD1 acquires a signal indicating the temperature of the power device PT from the temperature sensor TS (S1). The AD conversion circuit AD1 converts the signal (analog signal) into an AD format that can be processed by the correction processing circuit 413, and supplies the converted signal AD1 (digital signal) to the correction processing circuit 413.

[0118] The AD conversion circuit AD2 has an input node connected to the control terminal G of the power device PT, and an output node connected to the data conversion circuit CV.

[0119] The AD conversion circuit AD2 acquires a signal indicating the voltage of the control terminal G from the control terminal G of the power device PT (S2). The AD conversion circuit AD2 converts the signal (analog signal) into an AD format that can be processed by the correction processing circuit 413, and supplies the converted signal AD1 (digital signal) to the correction processing circuit 413.

[0120] The information conversion circuit CV receives the converted signal AD1 from the AD conversion circuit AD1 and receives the converted signal AD2 from the AD conversion circuit AD2. The information conversion circuit CV performs a predetermined filter process on the signal AD1 and the signal AD2 (S13) to obtain processed signals AD1a and AD2a.

[0121] The information conversion circuit CV refers to the correction information LUT and identifies a threshold voltage corresponding to the temperature indicated by the signal AD1a and the voltage indicated by the signal AD2a.

[0122] For example, the information conversion circuit CV may refer to a correction information LUT as shown in Fig. 11. Fig. 11 is a diagram showing the data structure of the correction information LUT in the second modified example of the embodiment.

[0123] The correction information LUT is the temperature T and the voltage V of the control terminal G. G and the threshold voltage Vth are temperature T and the voltage VG By referring to the correction information LUT, (T, V G )=(T1,V1) corresponds to the threshold voltage Vth=V 11 (T,V G )=(T2,V1) corresponds to the threshold voltage Vth=V 12 (T,V G )=(T3,V1) corresponds to the threshold voltage Vth=V 13 It can be identified that (T,V G )=(T1,V2) corresponds to the threshold voltage Vth=V 21 (T,V G )=(T2,V2) corresponds to the threshold voltage Vth=V 22 (T,V G )=(T3,V2) corresponds to the threshold voltage Vth=V 33 It can be identified that (T,V G )=(T5,V5) corresponds to the threshold voltage Vth=V 55 It can be identified as such.

[0124] That is, the information conversion circuit CV performs a calculation using the correction information LUT to generate a correction signal LUT corresponding to the signal AD1 and the signal AD2 (S14), and supplies the correction signal LUT to the voltage supply circuit .

[0125] The voltage supply circuit 42 includes a DA conversion circuit DA. In the DA conversion circuit DA, a front-stage part DAa functions as a control circuit 421, and a rear-stage part DAb functions as a variable voltage source 422.

[0126] The DA conversion circuit DA has an input node connected to the data conversion circuit CV and an output node connected to an input node 31 b of the comparison circuit 31 .

[0127] The DA conversion circuit DA receives the correction signal LUT from the information conversion circuit CV. The DA conversion circuit DA latches the correction signal LUT in synchronization with a timing signal (S15). The DA conversion circuit DA converts the latched correction signal LUT (digital signal) into a digital signal, and transmits the converted signal (analog signal) to the input node 31b of the comparison circuit 31 as a threshold voltage Vth. That is, the DA conversion circuit DA sets a threshold voltage Vth corresponding to the correction signal LUT to the input node 31b of the comparison circuit 31 (S16). In response to this, the protection circuit 3 including the comparison circuit 31 can perform DESAT detection using the threshold voltage Vth corresponding to the correction signal ADD (S7).

[0128] Such a temperature compensation circuit 4i also compensates for the temperature T of the power device PT and the voltage V of the control terminal G. G The threshold voltage Vth according to the above can be corrected, and the corrected threshold voltage Vth can be supplied to the input node 31b of the comparison circuit 31.

[0129] (Third Modification of the Embodiment) The temperature compensation circuit 4 may operate as shown in Fig. 12. Fig. 12 is a diagram showing the operation of the temperature compensation circuit 4 in the third modified example of the embodiment.

[0130] In the temperature compensation circuit 4, a correction circuit 41 is configured to calculate the temperature T of the power device PT and the voltage V of the control terminal G. G The correction circuit 41 generates a correction signal according to the voltage V G For each temperature T, a correction signal may be generated to instruct correction to the threshold voltage Vth so that the current of the power device PT at different temperatures T is kept constant.

[0131] For example, voltage V G When V = V1, the voltage V across the power transistor PT D and current I D The relationship between the current and the temperature is as shown in Figure 12(a). If the temperature T = T1, the current changes as shown by the solid line, if the temperature is higher, T = T2 (> T1), the current changes on the lower current side as shown by the dashed line, and if the temperature is higher, T = T3 (> T2), the current changes on the lower current side as shown by the dashed double dot line.

[0132] The current to be maintained at different temperatures T=T1, T2, T3 is I D =I 13 The current to be maintained may be a rated current at the lowest temperature T among the different temperatures T. At temperatures T=T1, T2, and T3, the current I D =I 13 The voltage V D =V 111 ,V 112 ,V 13 may be the level of the threshold voltage to be corrected. 111 ,V 112 ,V 13 are, in turn, larger.

[0133] The correction circuit 41 is G )=(T1,V1), the threshold voltage is set to level V 111 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 111 and supplies it to the input node 31 b of the comparison circuit 31 .

[0134] The correction circuit 41 is G )=(T2,V1), the threshold voltage is set to level V 112 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 112 and supplies it to the input node 31 b of the comparison circuit 31 .

[0135] The correction circuit 41 is G )=(T3,V1), the threshold voltage is set to the level V 13 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 13 and supplies it to the input node 31 b of the comparison circuit 31 .

[0136] Or, the voltage V GWhen V2 (> V1), the voltage VD and current I of the power transistor PT D The relationship between the current and the capacitance is as shown in Figure 12(b). If the temperature T = T1, the capacitance changes as shown by the solid line, if the temperature is higher, T = T2 (> T1), the capacitance changes on the lower current side as shown by the dashed line, and if the temperature is higher, T = T3 (> T2), the capacitance changes on the lower current side as shown by the dashed double dot line.

[0137] The current to be maintained at different temperatures T=T1, T2, T3 is I D =I 23 The current to be maintained may be a rated current at the lowest temperature T among the different temperatures T. At temperatures T=T1, T2, and T3, the current I D =I 23 The voltage V D =V 121 ,V 122 ,V 23 may be the level of the threshold voltage to be corrected. 121 ,V 122 ,V 23 are, in turn, larger.

[0138] The correction circuit 41 is G )=(T1,V2), the threshold voltage is set to level V 121 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 121 and supplies it to the input node 31 b of the comparison circuit 31 .

[0139] The correction circuit 41 is G )=(T2,V2), the threshold voltage is set to level V 122 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 122 and supplies it to the input node 31 b of the comparison circuit 31 .

[0140] The correction circuit 41 is G )=(T3,V2), the threshold voltage is set to level V23 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 23 and supplies it to the input node 31 b of the comparison circuit 31 .

[0141] In addition, when the temperature compensation circuit 4 is configured as shown in FIG. 4, the control circuit 8 may set the gain of the variable amplifier AM1 to correspond to the increase in the signal of the temperature T from T1 to T2 to T3, and the voltage V G A gain corresponding to increasing the signal from V1 to V2 may be set in the variable amplifier AM2.

[0142] According to the operation of the temperature compensation circuit 4, the current I of the power transistor PT for different temperatures T D Since the load LD can be maintained constant, it is possible to easily perform a failure analysis of the load LD when an overcurrent flows from the load LD.

[0143] (Fourth Modification of the Embodiment) The operation of the temperature compensation circuit 4 may be a combination of the operation shown in Fig. 7 and the operation shown in Fig. 12. The temperature compensation circuit 4 may operate as shown in Fig. 13. Fig. 13 is a diagram showing the operation of the temperature compensation circuit 4 in a fourth modified example of the embodiment.

[0144] In the temperature compensation circuit 4, a correction circuit 41 is configured to calculate the temperature T of the power device PT and the voltage V of the control terminal G. G The correction circuit 41 generates a correction signal according to the voltage V G For each temperature range, a correction signal may be generated that instructs correction to a threshold voltage Vth such that the current of the power device PT at different temperatures T is maintained constant, and a correction signal may be generated that instructs correction to a threshold voltage Vth corresponding to the rated current of the power device PT at temperature T, in a first temperature range.

[0145] For example, voltage V G When V = V1, the voltage V across the power transistor PT D and current ID The relationship between these two is as shown in Figure 13(a). If the temperature T = T1, it changes as shown by the solid line, if the temperature is higher, T = T2 (> T1), it changes on the lower current side as shown by the dashed line, and if the temperature is higher, T = T3 (> T2), it changes on the lower current side as shown by the dashed double dot line.

[0146] The current to be maintained at different temperatures T=T1, T2 is I D =I 12 Let the rated current at temperatures T=T2 and T3 be I D =I 12 ,I 13 At temperatures T=T1 and T2, the current I D =I 12 The voltage V D =V 211 ,V 12 may be the level of the threshold voltage to be corrected. 211 ,V 12 At temperatures T=T2 and T3, the current I D =I 12 ,I 13 The voltage V D =V 12 ,V 13 may be the level of the threshold voltage to be corrected. 12 ,V 13 are in turn smaller.

[0147] The correction circuit 41 is G )=(T1,V1), the threshold voltage is set to level V 211 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 211 and supplies it to the input node 31 b of the comparison circuit 31 .

[0148] The correction circuit 41 is G )=(T2,V1), the threshold voltage is set to level V 12The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 12 and supplies it to the input node 31 b of the comparison circuit 31 .

[0149] The correction circuit 41 is G )=(T3,V1), the threshold voltage is set to the level V 13 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 13 and supplies it to the input node 31 b of the comparison circuit 31 .

[0150] Or, the voltage V G When V2 (> V1), the voltage VD and current I of the power transistor PT D The relationship between the current and the capacitance is as shown in Figure 13(b). If the temperature T = T1, the capacitance changes as shown by the solid line, if the temperature is higher, T = T2 (> T1), the capacitance changes on the lower current side as shown by the dashed line, and if the temperature is higher, T = T3 (> T2), the capacitance changes on the lower current side as shown by the dashed double-dot line.

[0151] The current to be maintained at different temperatures T=T1, T2 is I D =I 22 Let the rated current at temperatures T=T2 and T3 be I D =I 22 ,I 23 At temperatures T=T1 and T2, the current I D =I 22 The voltage V D =V 221 ,V 22 may be the level of the threshold voltage to be corrected. 221 ,V 22 At temperatures T=T2 and T3, the current I D =I 22 ,I 23 The voltage V D =V 22 ,V 23 may be the level of the threshold voltage to be corrected.22 ,V 23 are in turn smaller.

[0152] The correction circuit 41 is G )=(T1,V2), the threshold voltage is set to level V 221 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 221 and supplies it to the input node 31 b of the comparison circuit 31 .

[0153] The correction circuit 41 is G )=(T2,V2), the threshold voltage is set to level V 22 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 22 and supplies it to the input node 31 b of the comparison circuit 31 .

[0154] The correction circuit 41 is G )=(T3,V2), the threshold voltage is set to level V 23 The voltage supply circuit 42 generates a correction signal including an instruction to correct the threshold voltage Vth to a level V 23 and supplies it to the input node 31 b of the comparison circuit 31 .

[0155] In addition, when the temperature compensation circuit 4 is configured as shown in FIG. 4, the control circuit 8 may set the gain of the variable amplifier AM1 to correspond to the increase in the signal of the temperature T from T1 to T2 to T3, and the voltage V G A gain corresponding to increasing the signal from V1 to V2 may be set in the variable amplifier AM2.

[0156] According to the operation of the temperature compensation circuit 4, the current I of the power transistor PT changes with respect to different temperatures T in the first temperature range. DSince the load LD can be maintained constant, it is easy to perform failure analysis of the load LD when an overcurrent flows from the load LD. In addition, in the second temperature range, the temperature T and the voltage V of the control terminal G can be calculated while securing the current margin of the power device PT. G It is possible to perform DESAT detection of the power device PT at a threshold voltage Vth according to the above.

[0157] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0158] 1 semiconductor device, 2 semiconductor integrated circuit, 3 protection circuit, 3, 4i temperature compensation circuit, 41 correction circuit, 42 voltage supply circuit.

Claims

1. a correction circuit having a first input node connected to a temperature sensor near a power device, a second input node connected to a control terminal of the power device, and an output node; a voltage supply circuit having an input node connected to an output node of the correction circuit, and an output node connected to a second input node of a comparison circuit having a first input node and a second input node connected to one end of the power device; A temperature compensation circuit with

2. the correction circuit generates a correction signal according to a temperature of the power device and a voltage of a control terminal; The voltage supply circuit corrects a threshold voltage in response to the correction signal, and supplies the corrected threshold voltage to a second input node of the comparison circuit.

2. The temperature compensation circuit of claim 1.

3. The voltage supply circuit does not correct a threshold voltage during a first period in which the comparator circuit outputs a first comparison result, and corrects the threshold voltage during a second period in which the comparator circuit outputs a second comparison result.

2. The temperature compensation circuit of claim 1.

4. The correction circuit includes: a first amplifier having a variable gain and an input node connected to a temperature sensor near the power device, and an output node; a second amplifier having a variable gain and an input node connected to the control terminal of the power device, and an output node; a signal generating circuit having a first input node connected to an output node of the first amplifier and a second input node connected to an output node of the second amplifier, and an output node; have 2. The temperature compensation circuit of claim 1.

5. The correction circuit includes: a first AD conversion circuit having an input node connected to a temperature sensor near the power device and an output node; a second AD conversion circuit having an input node connected to a control terminal of the power device and an output node; an information conversion circuit having a first input node connected to an output node of the first AD conversion circuit and a second input node and an output node connected to an output node of the second AD conversion circuit, and holding correction information in which temperature, a voltage at a control terminal, and a threshold voltage are associated with each other for a plurality of combinations of temperature and voltage at the control terminal; a DA conversion circuit having an input node connected to an output node of the information conversion circuit, and an output node; have 2. The temperature compensation circuit of claim 1.

6. the correction circuit generates a first correction signal when a temperature of the power device is a first temperature and a voltage of a control terminal is a first voltage, and generates a second correction signal when a temperature of the power device is a second temperature higher than the first temperature and a voltage of the control terminal is the first voltage; The voltage supply circuit corrects a threshold voltage to a first level in response to the first correction signal, and corrects a threshold voltage to a second level lower than the first level in response to the second correction signal.

2. The temperature compensation circuit of claim 1.

7. the first level corresponds to a rated current of the power device at the first temperature; The second level corresponds to a rated current of the power device at the second temperature.

7. The temperature compensation circuit of claim 6.

8. the correction circuit generates a first correction signal when a temperature of the power device is a first temperature and a voltage of a control terminal is a first voltage, and generates a third correction signal when a temperature of the power device is a second temperature higher than the first temperature and a voltage of the control terminal is the first voltage; The voltage supply circuit corrects a threshold voltage to a first level in response to the first correction signal, and corrects a threshold voltage to a third level higher than the first level in response to the third correction signal.

2. The temperature compensation circuit of claim 1.

9. the first level corresponds to a first current in the power device; The third level corresponds to the first current of the power device.

9. The temperature compensation circuit of claim 8.

10. a protection circuit including a comparison circuit having a first input node, a second input node, and an output node connected to one end of a power device, and a signal generation circuit having an input node and an output node connected to the output node of the comparison circuit; a temperature compensation circuit according to any one of claims 1 to 9, comprising: a first input node connected to a temperature sensor near the power device, a second input node connected to a control terminal of the power device, and an output node connected to a second input node of the comparison circuit; a drive circuit having an input node to which an output node of the signal generating circuit is connected and an output node to which a control terminal of the power device is connected; A semiconductor integrated circuit comprising:

11. A semiconductor integrated circuit according to claim 10; a rectifying element connected between the semiconductor integrated circuit and one end of the power device; A semiconductor device comprising:

12. determining a threshold voltage according to a temperature of the power device and a voltage of a control terminal; supplying the determined threshold voltage to a second input node of a comparison circuit having a first input node and a second input node connected to one end of the power device; A temperature compensation method including:

13. The said decision: determining a threshold voltage to a first level when a temperature of the power device is at a first temperature and a voltage of a control terminal is at a first voltage, and determining a threshold voltage to a second level lower than the first level when a temperature of the power device is at a second temperature higher than the first temperature and a voltage of a control terminal is at the first voltage.

13. The temperature compensation method of claim 12.

14. the first level corresponds to a rated current of the power device at the first temperature; The second level corresponds to a rated current of the power device at the second temperature.

14. The temperature compensation method of claim 13.

15. The said decision: determining a threshold voltage to a first level when a temperature of the power device is at a first temperature and a voltage of the control terminal is at a first voltage, and determining a threshold voltage to a third level higher than the first level when a temperature of the power device is at a second temperature higher than the first temperature and a voltage of the control terminal is at the first voltage.

13. The temperature compensation method of claim 12.

16. the first level corresponds to a first current in the power device; The third level corresponds to the first current of the power device.

16. The temperature compensation method of claim 15.

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