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

Abstract

The invention relates to a temperature compensation circuit, a semiconductor integrated circuit, a semiconductor device and a temperature compensation method. 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 in the vicinity of the power device. The second input node is connected to the 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.

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 Art

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

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2018 / 0097515 Summary of the invention

[0006] Problems to be solved by the invention

[0007] 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 overcurrent.

[0008] Means for solving problems

[0009] According to one embodiment, a temperature compensation circuit having a correction circuit and a voltage supply circuit is provided. 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 the 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

[0010] Figure 1 is a circuit diagram showing the configuration of a semiconductor device according to an embodiment.

[0011] Figure 2 It is a diagram for explaining DESAT according to the embodiment.

[0012] Figure 3 : is a circuit diagram showing the structure of the temperature sensor according to the embodiment.

[0013] Figure 4 : is a circuit diagram showing the configuration of a temperature compensation circuit according to an embodiment.

[0014] Figure 5It is a timing chart showing the operation of the temperature compensation circuit according to the embodiment.

[0015] Figure 6 It is a waveform diagram showing the operation of the semiconductor device according to the embodiment.

[0016] Figure 7 It is a diagram showing the operation of the temperature compensation circuit according to the embodiment.

[0017] Figure 8 It is a diagram showing the configuration of a temperature sensor according to a first modified example of the embodiment.

[0018] Fig. 9 It is a circuit diagram showing the configuration of a temperature compensation circuit according to a second modified example of the embodiment.

[0019] Fig.10 It is a timing chart showing the operation of the temperature compensation circuit according to the second modified example of the embodiment.

[0020] Fig.11 It is a diagram showing the data structure of correction information according to the second variation of the embodiment.

[0021] Fig.12 It is a diagram showing the operation of the correction circuit according to the third modified example of the embodiment.

[0022] Fig.13 It is a diagram showing the operation of the correction circuit according to the fourth modified example of the embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, a semiconductor device according to an embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiment.

[0024] (Implementation Method)

[0025] The semiconductor device of the embodiment is connected to the control terminal of the power device to drive the power device, but research is being conducted to appropriately protect the power device from overcurrent.

[0026] The semiconductor device 1 may also be Figure 1 The control terminal G of the power device PT as shown is connected to drive the power device PT. Figure 1 : is a circuit diagram showing the structure of the semiconductor device 1.

[0027] The power device PT is used to connect to a load LD that operates with a relatively large current and 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.

[0028] The power device PT can be any device that can handle relatively large current. The power device PT can 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 can be a SiC substrate or a Si substrate.

[0029] When a short circuit or other fault occurs in the load LD, an overcurrent may flow in the power device PT. In order to protect the power device PT from the overcurrent, it is effective to detect the start of the overcurrent flowing in the power device PT and perform a protection operation to cut off the power device PT accordingly. The start of the overcurrent flowing in the power device PT can be detected by detecting DESAT (hereinafter referred to as DESAT detection).

[0030] DESAT can be used as Figure 2 Defined as shown. Figure 2 This is a diagram for explaining DESAT.

[0031] For example, when the power device PT is an N-type IGBT, Figure 2 As shown in (a), one end of the power device PT becomes the collector C, the other end becomes the emitter E, and the control terminal becomes the gate G.

[0032] like Figure 2 As shown in (b), the power device PT is, when the voltage V between the gate G and the emitter E CE When the voltage V between collector C and emitter E exceeds the specified value and turns on, in region RG1, CE The current I from the collector C to the emitter E increases. C In the region RG2 on the higher voltage side, relative to the voltage V CE The increase of current I C Increase slowly.

[0033] like Figure 2 As shown by the blank arrow in (b), the current IC The steep region RG1 directs the current I C The gentle transition of region RG2 is called DESAT. Region RG1 is sometimes called saturation region. Region RG2 is sometimes called active region.

[0034] In addition, when the power device PT is a P-type IGBT, the voltage polarity between the turned-on gate G and the emitter E is opposite and the collector current flows in the direction from the emitter E to the collector C, which is the same as the case where the power device PT is an N-type IGBT.

[0035] Alternatively, in the case where the power device PT is an N-type power MOSFET, as Figure 2 As shown in (c), one end of the power device PT becomes the drain D, the other end becomes the source S, and the control terminal becomes the gate G.

[0036] like Figure 2 As shown in (d), the power device PT is, when the voltage V between the gate G and the source S GS When the voltage V between the drain D and the source S exceeds the specified value and turns on, in the region RG11, DS The drain current I D In the region RG12 on the higher voltage side, relative to the voltage V D The increase of current I D Increase slowly.

[0037] like Figure 2 As shown by the blank arrow in (d), the current I D The steep area RG11 is directed to the current I D The gentle transition of region RG12 is called DESAT. Region RG11 is sometimes called linear region. Region RG12 is sometimes called saturation region.

[0038] In addition, when the power device PT is a P-type power MOSFET, it is the same as the case where the power device PT is an N-type power MOSFET, except that the polarity of the voltage between the turned-on gate G and the source S is opposite and the drain current flows in the direction from the source S toward the drain D.

[0039] Although not shown, when the power device PT is a bipolar transistor, one end of the power device PT becomes a collector, the other end becomes an emitter, and the control terminal becomes a base. The transition from a region where the current at both ends is steep to a region where the current at both ends is gentle is called DESAT.

[0040] The following description will focus 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 description can also be applied to the case where the power device PT is of other types.

[0041] Figure 1 The semiconductor device 1 shown has input nodes 1a to 1e and an output node 1f. Node 1a is connected to the outside (for example, a higher-level controller) and receives an input signal IN from the outside. Input node 1b is connected to one end D of a power transistor PT and one end of a load LD. Input node 1c is connected to a control terminal G of the power transistor PT. Input nodes 1d and 1e are connected to one end and the other end of a temperature sensor TS, respectively. Output node 1f is connected to a control terminal G of the power transistor PT.

[0042] One end D of the power device PT is connected to the input node 1b of the semiconductor device 1 and one end of the load LD, the other end S is connected to the ground potential, and the control terminal G is connected to the input node 1c and the output node 1e of the semiconductor device 1. The power device PT may also include a rectifying element (for example, a diode) that takes the direction from the other end S toward the one end D as a forward direction.

[0043] The temperature sensor TS is at least partially disposed near the power device PT and can detect the temperature of the power device PT. The temperature sensor TS outputs the detection result to the input nodes 1d and 1e.

[0044] The semiconductor device 1 includes a semiconductor integrated circuit 2, a rectifying element D DESAT , capacitor element C BLANK , resistance element R DESAT And the resistance element R G .

[0045] The semiconductor integrated circuit 2 may be formed of a single chip or may be divided into a plurality of 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 a ground potential.

[0046] Rectifier element D DESAT Connected between the terminal DESAT and one end D of the power device PT. Rectifier element D DESAT The direction from the terminal DESAT toward the end D is defined as the forward direction. DESAT It could also be a diode.

[0047] Capacitor element C BLANK One end of the DESAT terminal and the rectifier element D DESATThe node between them is connected, and the other end is connected to the ground potential. BLANK The capacitance value of can be predetermined according to the required operating characteristics of the protection circuit 3. BLANK The capacitance value can be determined based on the capacitance element C required by the DESAT detection of the power device PT. BLANK The charging characteristics (eg, RC time constant or charging time based on current source 32) are predetermined.

[0048] Resistor element R DESAT Connect the DESAT terminal to the rectifier element D DESAT The resistor element R DESAT The resistance value of can be predetermined according to the required operating characteristics of the protection circuit 3. DESAT The resistance value can be determined based on the capacitance element C required by the DESAT detection of the power device PT. BLANK The charging characteristics (e.g., RC time constant) are predetermined.

[0049] Resistor element R G Connected between the terminal DRV and the control terminal G of the power device PT. G The resistance value of can be predetermined according to the operational characteristics (eg, driving capability) required of the driving circuit 5 .

[0050] The semiconductor integrated circuit 2 includes a protection circuit 3 , a temperature compensation circuit 4 , and a drive circuit 5 .

[0051] 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 the drive circuit 5 with a signal Shutdown instructing the power device PT to shut down.

[0052] 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 the output node 31c via a terminal DESAT, a resistor element R DESAT And the rectifying element D DESAT The input node 31b is connected to one end D of the power transistor PT. The input node 31b is connected to a part of the temperature compensation circuit 4. For example, the variable voltage source 422 described later is connected to the input node 31b. The variable voltage source 422 generates a threshold voltage Vth according to the control signal Threshold and supplies it to the input node 31b. The output node 31c is connected to the signal generation circuit 34.

[0053] For example, the comparison circuit 31 compares the voltage V at the terminal DESAT DESATIt is compared with the threshold voltage Vth.

[0054] In the case where the input node 31a is a non-inverting input node and the input node 31b is an inverting input node, the comparison circuit 31 is such that if the voltage V DESAT If the voltage V is higher than the threshold voltage Vth, the comparison result of H level is output. DESAT If the voltage is lower than the threshold voltage Vth, an L-level comparison result is output.

[0055] In the case where the input node 31a is the inverting input node and the input node 31b is the non-inverting input node, the comparison circuit 31 is such that if the voltage V DESAT If the voltage V is higher than the threshold voltage Vth, the comparison result of L level is output. DESAT If the voltage is lower than the threshold voltage Vth, an H level comparison result is output.

[0056] One end of the current source 32 is connected to the power supply potential, and the other end is connected to the 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 that can supply a constant current to the capacitor element C via the terminal DESAT. BLANK The constant current supplied by the current source 32 can be predetermined according to the operating characteristics required by the protection circuit 3. The constant current supplied by the current source 32 can be predetermined according to the capacitance element C required for the DESAT detection of the power device PT. BLANK The charging characteristics (e.g., RC time constant) are predetermined.

[0057] The switch 33 is connected between the capacitor element C BLANK 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 the control terminal is connected to the signal generation circuit 35.

[0058] The switch 33 is configured to turn off the capacitive element C when receiving the control signal MASK of the non-active level (for example, L level) from the signal generating circuit 35. BLANK One end is cut off from the ground potential, so that the capacitance element C BLANK When the switch 33 receives the control signal MASK of the active level (for example, H level) from the signal generating circuit 35, it turns on to connect the capacitor element C BLANK One end of the capacitor is connected to the ground potential, and the capacitor C BLANK The charge is drawn out from one end and discharged to ground potential.

[0059] The signal generation circuit 34 is connected between the comparison circuit 31 and the drive circuit 5. The signal generation circuit 34 generates a control signal Shutdown for shutting down the drive circuit 5 in response to the inversion of the comparison result of the comparison circuit 31, and supplies the control signal to the drive circuit 5.

[0060] 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, during the period TP1 when the comparison circuit 31 outputs the comparison result of the L level, the signal generation circuit 34 supplies the control signal Shutdown of the non-active level to the drive circuit 5. During the period TP2 when the comparison circuit 31 outputs the comparison result of the H level, the signal generation circuit 34 supplies the control signal Shutdown of the active level to the drive circuit 5.

[0061] 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, during the period TP11 when the comparison circuit 31 outputs the comparison result of the H level, the signal generation circuit 34 supplies the control signal Shutdown of the non-active level to the protection circuit 3. During the period TP12 when the comparison circuit 31 outputs the comparison result of the L level, the signal generation circuit 34 supplies the control signal Shutdown of the active level to the drive circuit 5.

[0062] The signal generation circuit 35 is connected between the terminal IN and the switch 33. The signal generation circuit 35 generates a control signal MASK based on the input signal IN and supplies the control signal MASK to the switch 33.

[0063] The drive circuit 5 has an input node 5a, an output node 5b, and a control node 5c. The input node 5a is connected to the terminal IN. The output node 5b is connected to the terminal DRV and the resistor element R G The control node 5 c is connected to the control terminal G of the power transistor PT. The control node 5 c is connected to the protection circuit 3 .

[0064] The drive circuit 5 is connected between the terminal IN and the terminal DRV. While receiving the control signal Shutdown of the non-active level, the drive circuit 5 generates a drive signal DRV for switching according to the input signal IN and supplies it to the control terminal G of the power transistor PT. Thus, the power transistor PT can be switched.

[0065] When receiving the control signal Shutdown of the effective level, the driving circuit 5 generates a driving signal DRV to maintain the power transistor PT in the off state regardless of the input signal IN and supplies it to the control terminal G of the power transistor PT. As a result, the power transistor PT is maintained in the off state. As a result, the power transistor PT can be protected from the overcurrent generated in the load LD.

[0066] The temperature compensation circuit 4 is connected between the terminal GATE and the terminal TEMP and the protection circuit 3. The temperature compensation circuit 4 includes a correction circuit 41 and a voltage supply circuit 42. The correction circuit 41 is arranged between the terminal GATE and the terminal TEMP and the voltage supply circuit 42. The voltage supply circuit 42 is arranged between the correction circuit 41 and the protection circuit 3.

[0067] The correction circuit 41 generates a voltage V corresponding to the temperature of the power device PT and the control terminal G. G 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 31 b of the comparison circuit 31 .

[0068] 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 the terminal TEMP. One end of the 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 the power supply potential. The input node 41b is connected to the control terminal G of the power transistor PT via the terminal GATE. The output node 41c is connected to the voltage supply circuit 42.

[0069] The correction circuit 41 includes a temperature acquisition circuit 411, a voltage acquisition circuit 412, and a correction processing circuit 413. The temperature acquisition circuit 411 is connected between the terminal TEMP and the correction processing circuit 413. The voltage acquisition circuit 412 is connected between the terminal GATE and the correction processing circuit 413. The correction processing circuit 413 is connected between the temperature acquisition circuit 411 and the voltage acquisition circuit 412 and the voltage supply circuit 42.

[0070] 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 processable by the correction processing circuit 413 and supplies the converted signal to the correction processing circuit 413.

[0071] 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 41 b . 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 .

[0072] The correction circuit 41 receives a signal from the temperature acquisition circuit 411 and a signal from the 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 the output node 41c.

[0073] 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.

[0074] The voltage supply circuit 42 includes 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.

[0075] In the voltage supply circuit 42, the control circuit 421 receives the correction signal from the correction circuit 41. The control circuit 421 corrects the threshold voltage Vth according to the correction signal. The voltage supply circuit 42 generates a control signal Threshold indicating the threshold voltage Vth after correction and supplies it to the control node of the variable voltage source 422. The variable voltage source 422 adjusts the voltage generated according to the control signal Threshold, and supplies the adjusted voltage as the threshold voltage Vth to the input node 31b of the comparison circuit 31.

[0076] 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 the 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 according to the first correction signal.

[0077] Alternatively, when the temperature of the power device PT is the second temperature and the voltage of the control terminal G is the 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 the 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 according to the second correction signal.

[0078] Thus, in the semiconductor device 1 , DESAT detection of the power device PT can be performed at the threshold voltage Vth according to the temperature and the voltage of the control terminal G while ensuring the current margin of the power device PT.

[0079] The signal generation circuit 34, the signal generation 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 acquisition circuit 411 and the voltage acquisition circuit 412, respectively.

[0080] Figure 1 The temperature sensor TS shown in the figure can use any temperature sensor that can measure temperature. The temperature sensor TS can also be as follows Figure 3 As shown. Figure 3 : is a circuit diagram showing the structure of the temperature sensor TS.

[0081] The temperature sensor TS includes a sensor element SE and a filter circuit FC. The sensor element SE can be arranged near the power device PT. The sensor element SE includes a thermistor TH. The thermistor TH can be an NTC thermistor or a PTC thermistor. The resistance value of the thermistor TH changes depending on the temperature.

[0082] The filter circuit FC is connected between the sensor element SE and the semiconductor device 1. The filter circuit FC has a resistance element R FL1 , R FL2 , filter FL and capacitor element C FL . Resistor element R FL1 One end of is connected to one end of the thermistor TH, and the other end is connected to the other end of the thermistor TH. FL2 One end of the filter FL is connected to the other end of the thermistor TH, and the other end is connected to the ground potential. FL With the resistor element R FL1 , R FL2 The filter FL can be a low pass filter. The capacitor element C FL One end of is connected to the input node 1d of the semiconductor device 1 and the P-side node of the filter FL, and the other end is connected to the input node 1e of the semiconductor device 1 and the N-side node of the filter FL.

[0083] The filter circuit FC can filter the detection signal of the sensor element SE and supply 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 (P-side detection signal and 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.

[0084] In response to the change in the resistance value of the thermistor TH depending on the temperature, a current flows from the current source 7 through the terminal TEMP and the filter FL into the thermistor TH and the resistance element R FL1 , R FL2 The amount of current changes respectively. In the resistor element R FL1 , R FL2 The voltage generated at both ends of the capacitor changes depending on the temperature. This voltage passes through the filter FL and the capacitor element C FL The smoothed detection signal (P-side detection signal and N-type detection signal) is transmitted to the terminal TEMP and the terminal 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.

[0085] Figure 1 The temperature compensation circuit 4 shown can also be Figure 4 As shown, and as Figure 5 Act as shown. Figure 4 : is a circuit diagram showing the configuration of the temperature compensation circuit 4 . Figure 5 2 is a timing chart showing the operation of the temperature compensation circuit 4 .

[0086] 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 capacitive element C1.

[0087] The input node of the variable amplifier AM1 is connected to the temperature sensor TS, and the output node is connected to the adder ADD. The gain of the variable amplifier AM1 is variable. When calibrating the variable amplifier AM1, the gain can also be adjusted in advance according to the control from the control circuit 8. The value of the adjusted gain can be determined in advance by experiments.

[0088] The variable amplifier AM1 obtains a signal (S1) indicating the temperature of the power device PT from the temperature sensor TS, converts the signal format into a format processable by the correction processing circuit 413 by amplifying the signal according to its gain, and supplies the converted signal AM1 to the correction processing circuit 413.

[0089] The input node of the variable amplifier AM2 is connected to the control terminal G of the power device PT, and the output node is connected to the adder ADD via the switch SW. The gain of the variable amplifier AM2 is variable. When calibrating the variable amplifier AM2, the gain can also be adjusted in advance according to the control from the control circuit 8. The value of the adjusted gain can be determined in advance by experiments.

[0090] The variable amplifier AM2 obtains a signal (S2) indicating the voltage of the control terminal G from the power device PT. The variable amplifier AM2 converts the signal format into a format that can be processed by the correction processing circuit 413 by amplifying the signal according to its gain, and supplies the converted signal AM2 to the correction processing circuit 413.

[0091] One end of the switch SW1 is connected to the variable amplifier AM2, and the other end is connected to one end of the capacitive element C1 and the adder ADD. The other end of the capacitive element C1 is connected to the ground potential.

[0092] The switch SW1 can also be maintained in an on state and an off state according to a certain cycle. During the period when the switch SW1 is maintained in the on state, the signal AM2 amplified by the variable amplifier AM2 is sampled to the capacitor element C1, and during the period when the switch SW1 is maintained in the off state, the amplified signal AM2 is held by the capacitor element C1. As a result, the switch capacitor SC1 including the switch SW1 and the capacitor element C1 equivalently acts as a filter (S3), which can reduce the noise in the signal AM2 amplified by the variable amplifier AM2 and generate a signal AM2a after filtering.

[0093] The adder ADD receives the amplified signal AM1 from the variable amplifier AM1, receives the filtered signal AM2a from the switch capacitor SC1, and receives the signal offset from the control circuit 8. The signal offset can be determined in advance by experiments. The adder ADD adds the signal AM1, the signal AM2a, and the signal offset. That is, the adder ADD performs an operation (S4) to generate a correction signal ADD corresponding to the signal AM1, the signal AM2a, and the signal offset, and supplies the correction signal ADD to the voltage supply circuit 42.

[0094] 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 capacitive element C2.

[0095] The input node of the amplifier AM3 is connected to the adder ADD, and the output node is 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 capacitor C2. The other end of the capacitor C2 is connected to the ground potential.

[0096] The amplifier AM3 receives the correction signal ADD from the adder ADD, amplifies the correction signal ADD, and supplies the amplified correction signal ADD to the switch SW2 side.

[0097] The switch SW2 can also be maintained in an on state and an off state according to a certain cycle. The signal AM3 amplified by the amplifier AM3 during the period when the switch SW2 is maintained in the on state is sampled to the capacitor C2, and the amplified signal AM3 is maintained by the capacitor C2 during the period when the switch SW2 is maintained in the off state. That is, the signal AM3 corresponding to the correction signal ADD is maintained by the capacitor C2 (S5). As a result, the switch capacitor SC2 including the switch SW2 and the capacitor C2 acts equivalently as a filter, which can reduce the noise in the signal AM3 amplified by the amplifier AM3 and generate a signal AM3a after filtering. Corresponding to the signal AM3a after filtering, the capacitor C2 generates a threshold voltage Vth at both ends thereof and transmits it to the input node 31b of the comparison circuit 31. That is, the capacitor C2 sets the threshold voltage Vth corresponding to the correction signal ADD to the input node 31b of the comparison circuit 31 (S6). Correspondingly, the protection circuit 3 including the comparison circuit 31 can use the threshold voltage Vth corresponding to the correction signal ADD to perform DESAT detection (S7).

[0098] Second, use Figure 6 The time-series operation of the semiconductor device 1 will be described. Figure 6 It is a waveform diagram showing the operation of the semiconductor device 1 .

[0099] Immediately before timing t1, the protection circuit 3 sets the control signal MASK to an active level and maintains the switch 33 in an on state. As a result, the DESAT detection of the protection circuit 3 is invalidated.

[0100] At timing t1, when the rising edge of the waveform of the input signal INPUT is detected, the drive circuit 5 turns the drive signal V GATE_DRIVE Set to an effective level.

[0101] At timing t2, when the driving signal V GATE_DRIVE When the voltage V at the control terminal G reaches an effective level (for example, H level), G begins to rise, and accordingly, the power device PT begins to conduct. Accordingly, a current I begins to flow in the power device PT D , and the voltage V at one end D D Start to descend.

[0102] The protection circuit 3 sets the control signal MASK to a non-active level and turns off the switch 33. In response, the protection circuit 3 enables the DESAT detection. That is, the protection circuit 3 is in a state where the DESAT of the power device PT can be detected.

[0103] At timing t3, the current I D Stable at a specified level, and the voltage V at one end D D When the voltage drops to a reference level (eg, L level), the transition of the power device PT to the on state is completed.

[0104] In addition, during the period from t1 to t3, the voltage V DESAT may rise temporarily, but is lower than the threshold voltage Vth. Therefore, the protection circuit 3 does not DESAT The temporary rise detection is DESAT.

[0105] At timing t4, when an excessive current I starts to flow into the power device PT in the on state due to a short circuit of the load LD or the like, D When the voltage V D begins to rise sharply, and accordingly, the voltage V DESAT It also began to rise sharply.

[0106] At timing t5, when the voltage V DESAT When the voltage is higher than 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.

[0107] In response to this, at timing t6, the protection circuit 3 changes the control signal Shutdown to an active level and supplies it to the drive circuit 5. The drive circuit 5 changes the drive signal V DRV In response, the power device PT starts to turn off, and the current I D The voltage V at one end D starts to decrease. D Continue to rise.

[0108] At timing t7, the voltage V D When the drive signal V DRV The voltage drops to near the reference level (eg, L level). Thus, the power device PT is controlled to be turned off.

[0109] At timing t8, the driving signal V GATE_DRIVE The transition to the non-active level (eg, L level) is completed, and at timing t9, the current I flowing into the terminal D of the power device PT D When the voltage drops to the reference level, the power device PT completes the transition to the cut-off state.

[0110] Second, use Figure 7 The operation of the temperature compensation circuit 4 will be described. Figure 7 2 is a diagram showing the operation of the temperature compensation circuit 4 .

[0111] In the temperature compensation circuit 4, the correction circuit 41 generates a voltage V corresponding to the temperature T of the power device PT and the control terminal G. G The correction circuit 41 can also be used for each voltage V G A correction signal instructing correction to a threshold voltage Vth corresponding to the rated current of the power device PT at temperature T is generated.

[0112] For example, at voltage V G = V1, the voltage across the power transistor PT is V D With current I D The relationship between Figure 7 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0113] The rated currents at temperatures T = T1, T2, and T3 are set to I D =I 11 ,I 12 ,I 13 In other words, the rated current can be called the upper limit of the allowable current at that temperature. At temperatures T = T1, T2, and T3, the current I D =I 11 ,I 12 ,I 13 The corresponding voltage V D =V 11 、V 12 、V 13 As the threshold voltage level to be corrected. 11 、V 12 、V 13 Gets smaller in sequence.

[0114] Correction circuit 41 is based on (T, V G )=(T1, V1), generating a voltage including correcting the threshold voltage to level V 11 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 11 And supplied to the input node 31 b of the comparison circuit 31 .

[0115] Correction circuit 41 is based on (T, V G )=(T2, V1), generating a voltage including correcting the threshold voltage to level V 12 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 12 And supplied to the input node 31 b of the comparison circuit 31 .

[0116] Correction circuit 41 is based on (T, V G )=(T3, V1), generating a voltage including correcting the threshold voltage to level V 13 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 13 And supplied to the input node 31 b of the comparison circuit 31 .

[0117] Or, at voltage V G = V2 (> V1), the voltage across the power transistor PT is V D With current I D The relationship between Figure 7 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0118] The rated currents at temperatures T = T1, T2, and T3 are set to I D =I 21 ,I 22 ,I 23 In other words, the rated current can be called the upper limit of the allowable current at that temperature. At temperatures T = T1, T2, and T3, the current I D =I 21 ,I 22 ,I 23 The corresponding voltage V D =V 21 、V 22 、V 23 As the threshold voltage level to be corrected. 21 、V 22 、V 23 Gets smaller in sequence.

[0119] Correction circuit 41 is based on (T, V G )=(T1, V2), generating a voltage including correcting the threshold voltage to level V 21The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 21 And supplied to the input node 31 b of the comparison circuit 31 .

[0120] Correction circuit 41 is based on (T, V G )=(T2, V2), generating a voltage including correcting the threshold voltage to level V 22 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 22 And supplied to the input node 31 b of the comparison circuit 31 .

[0121] Correction circuit 41 is based on (T, V G )=(T3, V2), generating a voltage including correcting the threshold voltage to level V 23 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 23 And supplied to the input node 31 b of the comparison circuit 31 .

[0122] In addition, in the temperature compensation circuit 4, Figure 4 In the case of the structure shown in the figure, the control circuit 8 can set the gain of the variable amplifier AM1 corresponding to the case where the signal of the temperature T increases in the manner of T1 → T2 → T3, and can also set the gain of the variable amplifier AM2 corresponding to the case where the voltage V G The gain is equivalent to the case where the signal increases in the manner of V1→V2.

[0123] As described above, in the embodiment, in the temperature compensation circuit 4 of the semiconductor device 1, the correction circuit 41 generates a voltage V corresponding to the temperature T of the power device PT and the voltage V of the control terminal G. G 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. Thus, in the protection circuit 3 including the comparison circuit 31, the voltage Vth related to the temperature T of the power device PT and the voltage V of the control terminal G can be used. G The corresponding appropriate threshold voltage Vth is used for DESAT detection.

[0124] Furthermore, in the embodiment, in the temperature compensation circuit 4 of the semiconductor device 1, if the voltage of the control terminal G is the same voltage, the correction circuit 41 can generate a correction signal indicating that the higher the temperature of the power device PT becomes, the lower the level of correction is. The voltage supply circuit 42 corrects the threshold voltage Vth to the indicated level according to the correction signal. Thus, in the semiconductor device 1, the current margin of the power device PT can be ensured at a level that is consistent with the temperature T and the voltage V of the control terminal G. G The corresponding threshold voltage Vth is used for DESAT detection of the power device PT.

[0125] (First Modification of Implementation)

[0126] Alternatively, the temperature sensor TS can also be Figure 8 As shown. Figure 8 : is a circuit diagram showing the structure of a temperature sensor TSa according to a first modified example of the embodiment.

[0127] The temperature sensor TSa includes a sensor element SEa and a filter circuit FCa. The sensor element SEa may be arranged near the power device PT. The sensor element SEa includes a diode D TS . Diode D TS The forward voltage varies depending on temperature.

[0128] The filter circuit FC is connected between the sensor element SEa and the semiconductor device 1. The filter circuit FC has a resistor element R TS And the capacitor element C TS . Resistor element R TS One end of the diode D TS One end of the capacitor C is connected to the input node 1d of the semiconductor device 1. TS One end of the semiconductor device 1 is connected to the input node 1d and the resistor element R TS One end is connected to the input node 1e of the semiconductor device 1 and the diode D TS one end of the .

[0129] 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 (P-side detection signal and 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.

[0130] Corresponding to diode D TSWhen the forward voltage of the resistor changes depending on the temperature, the current source 7 is connected to the resistor element R via the terminal TEMP. TS The diode D TS The voltage at both ends of the temperature compensation circuit 4 changes. The voltage is smoothed by the filter FL and transmitted to the terminal TEMP and the terminal GND as a pair of detection signals (P-side detection signal and N-type detection signal) 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.

[0131] Such a temperature sensor TSa can also measure the temperature of the power device PT.

[0132] (Second Modification of Implementation)

[0133] The temperature compensation circuit 4i can also be Fig. 9 As shown, and as Fig.10 Act as shown. Fig. 9 : is a circuit diagram showing the structure of a temperature compensation circuit 4i according to a second modified example of the embodiment. Fig.10 4 is a timing chart showing the operation of the temperature compensation circuit 4i.

[0134] 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 the correction information LUT. The correction information LUT is the temperature T, the voltage V at the control terminal G, and the G and the threshold voltage Vth for the temperature T and the voltage V at the control terminal G G Multiple combinations of establish corresponding information.

[0135] An input node of the AD conversion circuit AD1 is connected to the temperature sensor TS, and an output node is connected to the information conversion circuit CV.

[0136] The AD conversion circuit AD1 obtains a signal (S1) indicating the temperature of the power device PT from the temperature sensor TS. The AD conversion circuit AD1 converts the signal (analog signal) into a format that can be processed by the correction processing circuit 413 by performing AD conversion on the signal, and supplies the converted signal AD1 (digital signal) to the correction processing circuit 413.

[0137] An input node of the AD conversion circuit AD2 is connected to the control terminal G of the power device PT, and an output node is connected to the information conversion circuit CV.

[0138] The AD conversion circuit AD2 obtains a signal (S2) indicating the voltage of the control terminal G from the control terminal G of the power device PT. The AD conversion circuit AD2 converts the signal (analog signal) into a format that can be processed by the correction processing circuit 413 by performing AD conversion on the signal, and supplies the converted signal AD1 (digital signal) to the correction processing circuit 413.

[0139] 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 filtering process on the signal AD1 and the signal AD2 (S13) to obtain processed signals AD1a and AD2a.

[0140] The information conversion circuit CV refers to the correction information LUT, and determines a threshold voltage corresponding to the temperature indicated by the signal AD1 a and the voltage indicated by the signal AD2 a .

[0141] For example, the information conversion circuit CV can also refer to Fig.11 Correction information LUT as shown. Fig.11 It is a diagram showing the data structure of the correction information LUT according to the second modification example of the embodiment.

[0142] The correction information LUT is the temperature T, the voltage V at the control terminal G G and the threshold voltage Vth for the temperature T and the voltage V at the control terminal G G By referring to the correction information LUT, it can be determined that (T, V G )=(T1, V1) The corresponding threshold voltage is Vth=V 11 . Can be determined as (T, V G )=(T2, V1) The corresponding threshold voltage is Vth=V 12 . Can be determined as (T, V G )=(T3, V1) The corresponding threshold voltage is Vth=V 13 . ...can be determined as (T, V G )=(T1, V2) The corresponding threshold voltage is Vth=V 21 . Can be determined as (T, V G )=(T2, V2) The corresponding threshold voltage is Vth=V 22 . Can be determined as (T, V G )=(T3, V2) The corresponding threshold voltage is Vth=V 33 . ...can be determined as (T, V G )=(T5, V5) The corresponding threshold voltage is Vth=V 55 .

[0143] That is, the information conversion circuit CV uses the correction information LUT to perform a calculation 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 42 .

[0144] The voltage supply circuit 42 includes a DA conversion circuit DA. In the DA conversion circuit DA, a front-stage portion DAa functions as a control circuit 421 , and a rear-stage portion DAb functions as a variable voltage source 422 .

[0145] The DA conversion circuit DA has an input node connected to the information conversion circuit CV, and an output node connected to the input node 31 b of the comparison circuit 31 .

[0146] 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 the timing signal (S15). The DA conversion circuit DA performs DA conversion on the latched correction signal LUT (digital signal), and transmits the converted signal (analog signal) as the threshold voltage Vth to the input node 31b of the comparison circuit 31. That is, the DA conversion circuit DA sets the threshold voltage Vth corresponding to the correction signal LUT to the input node 31b of the comparison circuit 31 (S16). Accordingly, 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).

[0147] According to such a temperature compensation circuit 4i, it is also possible to compensate for the temperature T of the power device PT and the voltage V of the control terminal G. G The corresponding threshold voltage Vth is corrected, and the corrected threshold voltage Vth is supplied to the input node 31 b of the comparison circuit 31 .

[0148] (Third Modification of Implementation)

[0149] The temperature compensation circuit 4 can also be Fig.12 Act as shown. Fig.12 It is a diagram showing the operation of the temperature compensation circuit 4 according to the third modified example of the embodiment.

[0150] In the temperature compensation circuit 4, the correction circuit 41 generates a voltage V corresponding to the temperature T of the power device PT and the control terminal G. G The correction circuit 41 can also be used for each voltage V G A correction signal is generated, the correction signal indicating the threshold voltage Vth that is corrected so that the current of the power device PT at different temperatures T is maintained constant.

[0151] For example, at voltage VG = V1, the voltage across the power transistor PT is V D With current I D The relationship between Fig.12 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0152] The current to be maintained at different temperatures T = T1, T2, T3 is set to I D =I 13 The current to be maintained can also be the rated current at the lowest temperature T among different temperatures T. When the temperature T = T1, T2, T3, the current I D =I 13 The corresponding voltage V D =V 111 、V 112 、V 13 As the threshold voltage level to be corrected. 111 、V 112 、V 13 Getting bigger in turn.

[0153] Correction circuit 41 is based on (T, V G )=(T1, V1), generating a voltage including correcting the threshold voltage to level V 111 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 111 And supplied to the input node 31 b of the comparison circuit 31 .

[0154] Correction circuit 41 is based on (T, V G )=(T2, V1), generating a voltage including correcting the threshold voltage to level V 112 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 112 And supplied to the input node 31 b of the comparison circuit 31 .

[0155] Correction circuit 41 is based on (T, V G )=(T3, V1), generating a voltage including correcting the threshold voltage to level V 13 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 13 And supplied to the input node 31 b of the comparison circuit 31 .

[0156] Or, at voltage V G = V2 (> V1), the voltage across the power transistor PT is V D With current I D The relationship between Fig.12 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0157] The current to be maintained at different temperatures T = T1, T2, T3 is set to I D =I 23 The current to be maintained can also be the rated current at the lowest temperature T among different temperatures T. When the temperature T = T1, T2, T3, the current I D =I 23 The corresponding voltage V D =V 121 、V 122 、V 23 As the threshold voltage level to be corrected. 121 、V 122 、V 23 Getting bigger in turn.

[0158] Correction circuit 41 is based on (T, V G )=(T1, V2), generating a voltage including correcting the threshold voltage to level V 121 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 121 And supplied to the input node 31 b of the comparison circuit 31 .

[0159] Correction circuit 41 is based on (T, V G )=(T2, V2), generating a voltage including correcting the threshold voltage to level V 122 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 122 And supplied to the input node 31 b of the comparison circuit 31 .

[0160] Correction circuit 41 is based on (T, V G )=(T3, V2), generating a voltage including correcting the threshold voltage to level V 23 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 23And supplied to the input node 31 b of the comparison circuit 31 .

[0161] In addition, in the temperature compensation circuit 4, Figure 4 In the case of the structure shown in the figure, the control circuit 8 can set the gain of the variable amplifier AM1 corresponding to the case where the signal of the temperature T increases in the manner of T1→T2→T3, and can set the gain of the variable amplifier AM2 corresponding to the case where the voltage V G The gain is equivalent to the case where the signal increases in the manner of V1→V2.

[0162] According to the operation of the temperature compensation circuit 4, the current I of the power transistor PT can be adjusted according to the temperature T. D Since it is maintained constant, when an overcurrent flows from the load LD, a failure analysis of the load LD can be easily performed.

[0163] (Fourth Modification of Implementation Method)

[0164] The operation of the temperature compensation circuit 4 can also be Figure 7 The actions shown are similar to Fig.12 The temperature compensation circuit 4 can also be as follows Fig.13 Act as shown. Fig.13 It is a diagram showing the operation of the temperature compensation circuit 4 according to the fourth modified example of the embodiment.

[0165] In the temperature compensation circuit 4, the correction circuit 41 generates a voltage V corresponding to the temperature T of the power device PT and the control terminal G. G The correction circuit 41 can be used for each voltage V G In the first temperature range, a correction signal is generated to indicate that the current of the power device PT at different temperatures T is corrected to maintain a certain threshold voltage Vth, and in the second temperature range, a correction signal is generated to indicate that the threshold voltage Vth is corrected to correspond to the rated current of the power device PT at temperature T.

[0166] For example, at voltage V G = V1, the voltage across the power transistor PT is V D With current I D The relationship between Fig.13 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0167] The current to be maintained at different temperatures T = T1, T2 is set to I D =I 12, the rated current at temperature T = T2, T3 is set to I D =I 12 ,I 13 When the temperature T = T1, T2, the current I D =I 12 The corresponding voltage V D =V 211 、V 12 Set to the threshold voltage level to be corrected. V 211 、V 12 At temperatures T = T2, T3, the current I D =I 12 ,I 13 The corresponding voltage V D =V 12 、V 13 Set to the threshold voltage level to be corrected. V 12 、V 13 Gets smaller in sequence.

[0168] Correction circuit 41 is based on (T, V G )=(T1, V1), generating a voltage including correcting the threshold voltage to level V 211 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 211 And supplied to the input node 31 b of the comparison circuit 31 .

[0169] Correction circuit 41 is based on (T, V G )=(T2, V1), generating a voltage including correcting the threshold voltage to level V 12 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 12 And supplied to the input node 31 b of the comparison circuit 31 .

[0170] Correction circuit 41 is based on (T, V G )=(T3, V1), generating a voltage including correcting the threshold voltage to level V 13 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 13 And supplied to the input node 31 b of the comparison circuit 31 .

[0171] Or, at voltage V G = V2 (> V1), the voltage across the power transistor PT is V D With current I D The relationship between Fig.13 If the temperature T = T1, it changes as shown by the solid line. If the higher temperature T = T2 (> T1), it changes as shown by the dotted line on the lower current side. If the higher temperature T = T3 (> T2), it changes as shown by the double-dotted line on the lower current side.

[0172] The current to be maintained at different temperatures T = T1, T2 is set to I D =I 22 , the rated current at temperature T = T2, T3 is set to I D =I 22 ,I 23 When the temperature T = T1, T2, the current I D =I 22 The corresponding voltage V D =V 22 1. V 22 Set to the threshold voltage level to be corrected. V 221 、V 22 At temperatures T = T2 and T3, the current I D =I 22 ,I 23 The corresponding voltage V D =V 22 、V 23 Set to the threshold voltage level to be corrected. V 22 、V 23 Gets smaller in sequence.

[0173] Correction circuit 41 is based on (T, V G )=(T1, V2), generating a voltage including correcting the threshold voltage to level V 221 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 221 And supplied to the input node 31 b of the comparison circuit 31 .

[0174] Correction circuit 41 is based on (T, V G )=(T2, V2), generating a voltage including correcting the threshold voltage to level V 22 The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 22 And supplied to the input node 31 b of the comparison circuit 31 .

[0175] Correction circuit 41 is based on (T, V G )=(T3, V2), generating a voltage including correcting the threshold voltage to level V 23The correction signal indicated by the voltage supply circuit 42 is supplied to the voltage supply circuit 42. The voltage supply circuit 42 corrects the threshold voltage Vth to the level V according to the correction signal. 23 And supplied to the input node 31 b of the comparison circuit 31 .

[0176] In addition, in the temperature compensation circuit 4, Figure 4 In the case of the structure shown in the figure, the control circuit 8 can set the gain of the variable amplifier AM1 corresponding to the case where the signal of the temperature T increases in the manner of T1→T2→T3, and can set the gain of the variable amplifier AM2 corresponding to the case where the voltage V G The gain is equivalent to the case where the signal increases in the manner of V1→V2.

[0177] According to the operation of the temperature compensation circuit 4, the current I of the power transistor PT can be adjusted to the value corresponding to the different temperatures T within the first temperature range. D The voltage V of the control terminal G is maintained constant, so when an overcurrent flows from the load LD, a failure analysis of the load LD can be easily performed. In addition, in the second temperature range, the current margin of the power device PT can be ensured while the voltage V of the control terminal G is controlled at a constant temperature. G The corresponding threshold voltage Vth is used for DESAT detection of the power device PT.

[0178] Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are included in the invention described in the scope of the patent claim and the scope equivalent thereto.

Claims

1. A temperature compensation circuit, comprising: a correction circuit having 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; and The voltage supply circuit has an input node connected to the output node of the correction circuit and an output node connected to the second input node of the comparison circuit. The comparison circuit has a first input node and a second input node connected to one end of the power device.

2. The temperature compensation circuit according to claim 1, wherein: The correction circuit generates a correction signal corresponding to the temperature of the power device and the voltage of the control terminal. The voltage supply circuit corrects the threshold voltage based on the correction signal and supplies the corrected threshold voltage to the second input node of the comparison circuit.

3. The temperature compensation circuit according to claim 1, wherein: The voltage supply circuit does not correct the threshold voltage during a first period when the comparison circuit outputs a first comparison result, and corrects the threshold voltage during a second period when the comparison circuit outputs a second comparison result.

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

5. The temperature compensation circuit according to claim 1, wherein: The correction circuit has: 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 the control terminal of the power device and an output node; An information conversion circuit having a first input node connected to the output node of the first AD conversion circuit, a second input node connected to the output node of the second AD conversion circuit, and an output node, and maintaining correction information corresponding to a plurality of combinations of temperature, control terminal voltage, and threshold voltage; as well as The DA conversion circuit has an input node connected to the output node of the information conversion circuit, and an output node.

6. The temperature compensation circuit according to claim 1, wherein: The correction circuit generates a first correction signal when the temperature of the power device is a first temperature and the voltage of the control terminal is a first voltage, and generates a second correction signal when the temperature of the power device is a second temperature higher than the first temperature and the voltage of the control terminal is the first voltage. The voltage supply circuit corrects the threshold voltage to a first level based on the first correction signal, and corrects the threshold voltage to a second level lower than the first level based on the second correction signal.

7. The temperature compensation circuit according to claim 6, wherein: The first level corresponds to the 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.

8. The temperature compensation circuit according to claim 1, wherein: The correction circuit generates a first correction signal when the temperature of the power device is a first temperature and the voltage of the control terminal is a first voltage, and generates a third correction signal when the temperature of the power device is a second temperature higher than the first temperature and the voltage of the control terminal is the first voltage. The voltage supply circuit corrects the threshold voltage to a first level based on the first correction signal, and corrects the threshold voltage to a third level higher than the first level based on the third correction signal.

9. The temperature compensation circuit according to claim 8, wherein: The first level corresponds to the first current of the power device. The third level corresponds to the first current of the power device.

10. A semiconductor integrated circuit comprising: A protection circuit including a comparison circuit having a first input node connected to one end of a power device, a second input node, and an output node, and a signal generation circuit having an input node and an output node connected to the output node of the comparison circuit; The 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 the second input node of the comparison circuit; as well as The driving circuit has an input node connected to the output node of the signal generating circuit and an output node connected to the control terminal of the power device.

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

12. A temperature compensation method, comprising: determining a threshold voltage corresponding to the temperature of the power device and the voltage of the control terminal; as well as The determined threshold voltage is supplied to a second input node of a comparison circuit having a first input node connected to one end of the power device and a second input node.

13. The temperature compensation method according to claim 12, wherein: The above decisions include: When the temperature of the power device is a first temperature and the voltage of the control terminal is a first voltage, the threshold voltage is determined to be a first level. When the temperature of the power device is a second temperature higher than the first temperature and the voltage of the control terminal is the first voltage, the threshold voltage is determined to be a second level lower than the first level.

14. The temperature compensation method according to claim 13, wherein: The first level corresponds to the 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.

15. The temperature compensation method according to claim 12, wherein: The above decisions include: When the temperature of the power device is the first temperature and the voltage of the control terminal is the first voltage, the threshold voltage is determined to be the first level. When the temperature of the power device is the second temperature higher than the first temperature and the voltage of the control terminal is the first voltage, the threshold voltage is determined to be the third level higher than the first level.

16. The temperature compensation method according to claim 15, wherein: The first level corresponds to the first current of the power device. The third level corresponds to the first current of the power device.

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