Semiconductor Devices

Abstract

he present invention suppresses oscillation in a sense current detection signal outputted from a power semiconductor element for current monitoring.　A voltage control circuit (1c) includes a diode (D1) for charging a gate voltage to be applied to the gate of a current monitoring element (1b) and a diode (D2) for discharging the gate voltage, and controls the gate voltage for the current monitoring element (1b). The collector of an output element (1a) and the collector of the current monitoring element (1b) are connected to a supply voltage via a terminal (C). The emitter of the output element (1a) is connected to a load (2) via a terminal (E). The sense emitter of the current monitoring element (1b) is connected to a terminal (SE). The anode of the diode (D1) is connected to the gate of the output element (1a) and the cathode of the diode (D2). The cathode of the diode (D1) is connected to the anode of the diode (D2) and the gate of the current monitoring element (1b).

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device Place Regarding. [Background technology]

[0002] In recent years, development of next-generation semiconductor elements such as silicon carbide (SiC) elements and gallium nitride (GaN) elements has been progressing as next-generation technologies for IGBTs (Insulated Gate Bipolar Transistors), which are power semiconductor elements.

[0003] As a related technique, for example, a technique has been proposed in which a transient sense period of a sense current detection signal is detected in response to the turn-on of a semiconductor element, and the semiconductor element is controlled based on the sense current detection signal during the transient sense period (Patent Document 1). Also, a semiconductor device has been proposed that includes an ON-side diode connected in a forward direction with respect to a positive gate voltage to an ON-side resistance wiring connected to the gate electrode of a sense IGBT cell, and an OFF-side diode connected in a reverse direction with respect to the positive gate voltage to an OFF-side resistance wiring of the sense IGBT cell (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 211840 [Patent Document 2] Japanese Patent Application Publication No. 2019-149558 Summary of the Invention [Problem to be solved by the invention]

[0005] A semiconductor device called an IPS (Intelligent Power Switch) includes a main IGBT, which is a power semiconductor element for operating a load, and a sense IGBT, which is a power semiconductor element for monitoring current and supplies a sense current proportional to the current flowing through the main IGBT. The IPS also includes an overcurrent detection circuit that detects overcurrent in the main IGBT using a detection signal of the sense current (sense current detection signal).

[0006] However, in the conventional IPS configuration described above, oscillation occurs in the sense current detection signal during the period from the transient rise to the fall of the sense current detection signal (transient sense period). In this case, for example, if oscillation of a voltage value that exceeds the rated value occurs, it may cause malfunction of the overcurrent detection circuit or destruction of devices such as IGBTs, reducing the reliability of device operation.

[0007] In one aspect, the present invention provides a semiconductor device that suppresses oscillations occurring in a detection signal of a sense current output from a power semiconductor element for current monitoring. Place The purpose is to provide. [Means for solving the problem]

[0008] To solve the above problems, a semiconductor device is provided. The semiconductor device has an output element, a current monitoring element, and a voltage control circuit. The output element operates a load by switching based on a drive signal. The current monitoring element monitors the current flowing through the output element. The voltage control circuit includes a first diode that charges a gate voltage applied to the gate of the current monitoring element and a second diode that discharges the gate voltage, thereby controlling the gate voltage. The anode of the first diode is connected to the gate of the output element and the cathode of the second diode, and the cathode of the first diode is connected to the anode of the second diode and the gate of the current monitoring element. The voltage control circuit further includes a capacitor, a first end of which is connected to the cathode of the first diode, the anode of the second diode and the gate of the current monitoring element, and a second end of which is connected to the emitter of the output element.

[0009] In addition, in order to solve the above problems, A semiconductor device is provided. The semiconductor device has an output element, a current monitoring element, and a voltage control circuit. The output element switches based on a drive signal to operate a load. The current monitoring element monitors the current flowing through the output element. The voltage control circuit includes a first diode that charges a gate voltage applied to the gate of the current monitoring element and a second diode that discharges the gate voltage, thereby controlling the gate voltage. The anode of the first diode is connected to the gate of the output element and the cathode of the second diode, and the cathode of the first diode is connected to the anode of the second diode and the gate of the current monitoring element. The voltage control circuit further includes a voltage divider circuit including a first resistor and a second resistor, wherein a first end of the first resistor is connected to the anode of the first diode, the cathode of the second diode, and the gate of the output element, a second end of the first resistor is connected to the cathode of the first diode, the anode of the second diode, the first end of the second resistor, and the gate of the current monitoring element, and a second end of the second resistor is connected to the sense emitter of the current monitoring element. The voltage control circuit further includes a capacitor, wherein a first end of the capacitor is connected to the cathode of the first diode, the anode of the second diode, the second end of the first resistor, and the gate of the current monitoring element, and a second end of the capacitor is connected to the second end of the second resistor and the sense emitter of the current monitoring element. Furthermore, to solve the above problems, a semiconductor device is provided. The semiconductor device includes an output element, a current monitoring element, and a voltage control circuit. The output element switches based on a drive signal to operate a load. The current monitoring element monitors a current flowing through the output element. The voltage control circuit includes a first diode that charges a gate voltage applied to the gate of the current monitoring element and a second diode that discharges the gate voltage, and controls the gate voltage. The anode of the first diode is connected to the gate of the output element and the cathode of the second diode, and the cathode of the first diode is connected to the anode of the second diode and the gate of the current monitoring element. The voltage control circuit further includes a resistor, a first end of the resistor connected to the cathode of the first diode, the anode of the second diode, and the gate of the current monitoring element, and a second end of the resistor connected to the sense emitter of the current monitoring element. The voltage control circuit further includes a capacitor, a first end of which is connected to the cathode of the first diode, the anode of the second diode, the first end of the resistor, and the gate of the current monitoring element, and a second end of which is connected to the second end of the resistor and the sense emitter of the current monitoring element. Furthermore, to solve the above-mentioned problems, a semiconductor device is provided. The semiconductor device includes an output element, a current monitoring element, and a voltage control circuit. The output element switches based on a drive signal to operate a load. The current monitoring element monitors a current flowing through the output element. The voltage control circuit includes a first diode that charges a gate voltage applied to the gate of the current monitoring element and a second diode that discharges the gate voltage, and controls the gate voltage. The anode of the first diode is connected to the gate of the output element and the cathode of the second diode, and the cathode of the first diode is connected to the anode of the second diode and the gate of the current monitoring element. The voltage control circuit further includes a resistor, a first end of the resistor connected to the cathode of the first diode, the anode of the second diode, and the gate of the current monitoring element, and a second end of the resistor connected to the sense emitter of the current monitoring element. [Effects of the Invention]

[0010] According to one aspect, a detection signal of a sense current output from a power semiconductor element for current monitoring is generated. Oscillation It becomes possible to suppress the above. The above and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings illustrating preferred embodiments of the present invention. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B are diagrams illustrating an example of a semiconductor device. [Figure 2] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 3] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 4] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 5] FIG. 10 is a diagram for explaining self-charging of a sense IGBT. [Figure 6] FIG. 10 is a diagram showing an example of a simulation waveform. [Figure 7] FIG. 10 is a diagram showing an example of a simulation waveform. [Figure 8] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 9] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 10] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 11] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device including an overcurrent protection circuit. [Figure 12] FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. [Figure 13] FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. [Figure 14] FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. [Figure 15]FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. [Figure 16] FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. [Figure 17] FIG. 1 is a diagram illustrating an example of the configuration of an overcurrent protection device. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functions are designated by the same reference numerals, and redundant description may be omitted.

[0013] 1 is a diagram illustrating an example of a semiconductor device. The semiconductor device 1 includes an output element 1a, a current monitoring element 1b, and a voltage control circuit 1c. The voltage control circuit 1c includes a diode D1 (first diode) that charges a gate voltage applied to the gate of the current monitoring element 1b, and a diode D2 (second diode) that discharges the gate voltage, and controls the gate voltage of the current monitoring element 1b.

[0014] The output element 1a and the current monitor element 1b are, for example, an IGBT or an RC (Reverse Conducting)-IGBT, which is an IGBT and an FWD (Free Wheeling Diode) integrated into a single chip. Alternatively, a SiC device may be used. Examples of SiC devices include SiC-MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). In the following description, the output element will be referred to as the main IGBT, and the current monitor element will be referred to as the sense IGBT.

[0015] The collector of the main IGBT 1a and the collector of the sense IGBT 1b are connected to the power supply voltage Vcc via a terminal C. The emitter of the main IGBT 1a is connected to the load 2 via a terminal E. The sense emitter of the sense IGBT 1b is connected to a terminal SE.

[0016] The anode of diode D1 is connected to terminal G, the gate of main IGBT1a and the cathode of diode D2, and the cathode of diode D1 is connected to the anode of diode D2 and the gate of sense IGBT1b.

[0017] Here, the main IGBT 1a switches on and off based on the drive signal s0 to operate the load 2. In this case, when the drive signal s0 commands the main IGBT 1a to turn on, the main IGBT 1a turns on and causes a current to flow from the collector to the emitter. The sense IGBT 1b is an element that monitors the current of the main IGBT 1a, and when the drive signal s0 commands the main IGBT 1a to turn on, a sense current proportional to the current flowing through the main IGBT 1a flows from the collector to the sense emitter.

[0018] 2 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-1 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c, and an overcurrent protection circuit 10. The overcurrent protection circuit 10 includes a resistor Rs (current detection resistor) and an overcurrent detection circuit 11. 1st The terminal is connected to the sense emitter of the sense IGBT 1b and the input terminal of the overcurrent detection circuit 11, and the terminal of the resistor Rs Second The terminal is connected to the emitter of the main IGBT 1 a and the load 2 .

[0019] Resistor Rs 1st The sense current output from the sense IGBT 1b is converted into a voltage and a sense current detection signal Vsense is output from the terminal. Moreover, the overcurrent detection circuit 11 detects an overcurrent state of the main IGBT 1a by comparing the sense current detection signal Vsense with a reference voltage.

[0020] In the semiconductor device 1-1 described above, the gate of the main IGBT 1 a and the gate of the sense IGBT 1 b are connected via a voltage control circuit 1 c, which reduces the influence of self-charge, which will be described later, and makes it possible to suppress oscillations occurring in the sense current detection signal Vsense during a transient sensing period of the sense current detection signal Vsense.

[0021] 3 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. Semiconductor device 1-1a includes main IGBT 1a, sense IGBT 1b, voltage control circuit 1c1, and overcurrent protection circuit 10. Voltage control circuit 1c1 includes diodes D1, D1a, and D2. The anode of diode D1a is connected to the cathode of diode D1, and the cathode of diode D1a is connected to the anode of diode D2 and the gate of sense IGBT 1b.

[0022] In this way, the semiconductor device 1-1a has a configuration in which the diode D1a is connected in series with the diode D1, and other configurations are the same as those in Fig. 2. Note that in the example of Fig. 3, the diode D1a is added to configure the charging side diodes in two series stages, but the number of series stages may be increased to three or more stages.

[0023] In the semiconductor device 1-1a described above, the gate of the main IGBT 1a and the gate of the sense IGBT 1b are connected via a voltage control circuit 1c1, which reduces the influence of self-charge, which will be described later, and makes it possible to suppress oscillations occurring in the sense current detection signal Vsense during a transient sensing period of the sense current detection signal Vsense.

[0024] 4 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-2 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-2, and an overcurrent protection circuit 10. The voltage control circuit 1c-2 includes diodes D1 and D2, and capacitor Includes C0.

[0025] capacitor C0 1st The terminal is connected to the cathode of diode D1, the anode of diode D2 and the gate of sense IGBT1b, capacitor C0 Second The other end is connected to the emitter of the main IGBT 1a. The rest of the configuration is the same as in Figure 2.

[0026] In the semiconductor device 1-2 described above, the gate of the main IGBT 1a and the gate of the sense IGBT 1b are connected via a voltage control circuit 1c-2, which reduces the influence of self-charge, which will be described later, and makes it possible to suppress oscillations occurring in the sense current detection signal Vsense during a transient sensing period of the sense current detection signal Vsense.

[0027] <Self-charging of sense IGBT> 5 is a diagram for explaining self-charging of the sense IGBT. In a power semiconductor element such as an IGBT, a phenomenon called self-charging occurs when the IGBT is turned on.

[0028] Self-charging is a phenomenon in which holes injected from the collector of the IGBT charge the gate oxide film around the trench, raising the gate voltage. When self-charge occurs, not only does the gate voltage rise due to the charge chg0 of the drive signal s0 output from the gate driver, but also the gate voltage rise due to the self-charge charge chg1.

[0029] Furthermore, the chip area of ​​the sense IGBT1b is usually smaller than the chip area of ​​the main IGBT1a. As such, there is a size relationship between the chip area of ​​the main IGBT1a and the chip area of ​​the sense IGBT1b, so the parasitic GE (gate-emitter) capacitance of the main IGBT1a is different from the parasitic GE capacitance of the sense IGBT1b.

[0030] For this reason, when a command to turn on the main IGBT 1a is issued by the drive signal s0, the sense IGBT 1b completes charging and starts turning on earlier than the main IGBT 1a, so the sense IGBT 1b turns on before the main IGBT 1a. As a result, the sense IGBT 1b is affected by the electromotive force due to physical differences in the wiring paths around the IGBTs more than the main IGBT 1a.

[0031] In this way, the rise in gate voltage due to the self-charge charge chg1 appears in the sense IGBT 1b earlier than in the main IGBT 1a. As a result, the sense current detection signal Vsense output based on the sense current flowing from the sense emitter of the sense IGBT 1b experiences oscillation during the transient sense period, with the waveform rising due to the self-charge charge chg1.

[0032] Furthermore, if the voltage level of the oscillation is high, as described above, it may cause malfunction of the overcurrent detection circuit or destruction of devices such as IGBTs. In view of these points, the present invention aims to suppress oscillation by connecting a voltage control circuit including bidirectional diodes (diodes D1 and D2) to the gate of the sense IGBT.

[0033] <Simulation waveform> 6 is a diagram showing an example of a simulation waveform, where the vertical axis represents the voltage (V) of the sense current detection signal Vsense and the horizontal axis represents time (s).

[0034] [Waveform k1] Waveform of the sense current detection signal Vsense of a semiconductor device (conventional device) that does not have a voltage control circuit. When the main IGBT 1a and the sense IGBT 1b are turned on, the sense current detection signal Vsense is output.

[0035] [Waveform k2] This is the waveform of the sense current detection signal Vsense of the semiconductor device 1-1 (FIG. 2) having the voltage control circuit 1c. In the semiconductor device 1-1, the forward voltage of the diode D1 VfThe effect of self-charge is suppressed by using the dropout voltage. Pressure This reduces the oscillation of the sense current detection signal Vsense.

[0036] [Waveform k3] This is the waveform of the sense current detection signal Vsense of the semiconductor device 1-1a (Figure 3) that has the voltage control circuit 1c1. As described above, the semiconductor device 1-1a has a configuration in which diode D1a is connected in series with diode D1, and the number of series stages is two for the diode on the charging side. By increasing the number of series stages, the forward voltage Vf can be lowered more than in the semiconductor device 1-1, and the gate voltage of the sense IGBT 1b can be further reduced. As a result, the oscillation of the sense current detection signal Vsense is further reduced.

[0037] In this way, the configuration of the present invention makes it possible to suppress oscillations occurring in the sense current detection signal Vsense during the transient sensing period of the sense current detection signal Vsense.

[0038] 7 is a diagram showing an example of a simulation waveform, where the vertical axis represents the voltage (V) of the sense current detection signal Vsense and the horizontal axis represents time (s). [Waveform k11] This is the waveform of the sense current detection signal Vsense of a semiconductor device (conventional device) that does not have a voltage control circuit. When the main IGBT 1a and the sense IGBT 1b are turned on, the sense current detection signal Vsense is output.

[0039] [Waveform k12] This is the waveform of the sense current detection signal Vsense of the semiconductor device 1-1 (FIG. 2) that has the voltage control circuit 1c. In the semiconductor device 1-1, the forward voltage drop of the diode D1 is used to lower the gate voltage of the sense IGBT 1b, thereby reducing the oscillation of the sense current detection signal Vsense.

[0040] [Waveform k13] This is the waveform of the sense current detection signal Vsense of the semiconductor device 1-2 (FIG. 4) having the voltage control circuit 1c-2. In the semiconductor device 1-2, as described above, in addition to the diodes D1 and D2, capacitor This is a configuration with C0.

[0041] Here, when the sense IGBT 1b is turned on at time t1, a voltage jump (overshoot) occurs in the sense current detection signal Vsense. capacitor By setting C0, capacitor C0 transfers the charge due to self-charge that accumulates in the gate of the sense IGBT 1b to the emitter of the main IGBT 1a.

[0042] As a result, in the semiconductor device 1-2, it is possible to suppress a decrease in the oscillation of the sense current detection signal Vsense, and further to suppress a jump in the gate voltage when the sense IGBT 1b is turned on.

[0043] <Modification> 8 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-3 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-3, and an overcurrent protection circuit 10. The voltage control circuit 1c-3 includes diodes D1 and D2 and resistors R1 (first resistor) and R2 (second resistor). The resistors R1 and R2 form a voltage divider circuit.

[0044] The collector of the main IGBT 1a and the collector of the sense IGBT 1b are connected to the power supply voltage Vcc via a terminal C. The emitter of the main IGBT 1a is connected to the load 2 via a terminal E.

[0045] The gate of the main IGBT1a is connected to terminal G, the anode of diode D1, the cathode of diode D2 and the terminal of resistor R1. 1st The gate of the sense IGBT1b is connected to the cathode of the diode D1, the anode of the diode D2, and the terminal of the resistor R1. Second end and resistor R2 1stconnected to the end of resistor R2. Second The end is connected to the sense emitter of sense IGBT1b and terminal SE.

[0046] The overcurrent protection circuit 10 also includes a resistor Rs (current detection resistor) and an overcurrent detection circuit 11. 1st The end is the sense emitter of the sense IGBT1b, the end of resistor R2 Second and the input terminal of the overcurrent detection circuit 11, and the resistor Rs Second The terminal is connected to the emitter of the main IGBT 1 a and the load 2 .

[0047] In the semiconductor device 1-3 as described above, a bidirectional diode including diodes D1 and D2 is arranged between the gate of the main IGBT 1a and the gate of the sense IGBT 1b in the voltage control circuit 1c-3, and further includes resistors R1 and R2 that divide the gate voltage of the main IGBT 1a and apply the divided voltage to the gate of the sense IGBT 1b.

[0048] In the configuration of the semiconductor device 1-3, it is also possible to suppress oscillations occurring in the sense current detection signal Vsense during the transient sensing period of the sense current detection signal Vsense. Not only the forward voltage drop across diode D1, By voltage dividing resistor too The gate voltage of the sense IGBT1b can be reduced ,difference Furthermore, the gate voltage of the sense IGBT 1b can be reduced, and the influence of self-charge can be efficiently suppressed.

[0049] 9 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-4 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-4, and an overcurrent protection circuit 10. The voltage control circuit 1c-4 includes diodes D1 and D2, resistors R1 and R2, and capacitor Includes C0.

[0050] capacitor C0 1stThe ends are the cathode of diode D1, the anode of diode D2, and the Second end, resistor R2 1st and the gate of Sense IGBT1b. capacitor C0 Second The end of resistor R2 Second The other configurations are the same as in FIG.

[0051] In the semiconductor device 1-4 as described above, a voltage control circuit 1c-4 includes a bidirectional diode including diodes D1 and D2 disposed between the gate of the main IGBT 1a and the gate of the sense IGBT 1b, and resistors R1 and R2 that divide the gate voltage of the main IGBT 1a and apply the divided voltage to the gate of the sense IGBT 1b. capacitor C0 is placed.

[0052] In the configuration of the semiconductor device 1-4, it is also possible to suppress oscillations occurring in the sense current detection signal Vsense during the transient sensing period of the sense current detection signal Vsense. Not only the forward voltage drop across diode D1, By voltage dividing resistor too The gate voltage of the sense IGBT1b can be reduced ,difference Furthermore, the gate voltage of the sense IGBT 1b can be reduced. capacitor C0 also has the effect of transferring the charge caused by self-charging to the sense emitter side.

[0053] 10 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-5 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-5, and an overcurrent protection circuit 10. The voltage control circuit 1c-5 includes diodes D1 and D2 and a resistor R3.

[0054] Resistor R3 1st The terminals of the resistor R3 are connected to the cathode of the diode D1, the anode of the diode D2, and the gate of the sense IGBT 1b. Second The other end is connected to the sense emitter of the sense IGBT 1b. The other configurations are the same as in Figure 2.

[0055] In the semiconductor device 1-5 as described above, in the voltage control circuit 1c-5, a bidirectional diode including diodes D1 and D2 is arranged between the gate of the main IGBT 1a and the gate of the sense IGBT 1b, and a resistor R3 is arranged between the gate and the sense emitter of the sense IGBT 1b.

[0056] In the configuration of the semiconductor device 1-5, it is also possible to suppress oscillations occurring in the sense current detection signal Vsense during the transient sensing period of the sense current detection signal Vsense. Not only the forward voltage drop across diode D1, By resistor R3 too Because it will further decrease ,difference Furthermore, the gate voltage of the sense IGBT 1b can be reduced, making it possible to suppress the influence of self-charge.

[0057] 11 is a diagram showing an example of the configuration of a semiconductor device including an overcurrent protection circuit. The semiconductor device 1-6 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-6, and an overcurrent protection circuit 10. The voltage control circuit 1c-6 includes diodes D1 and D2, a resistor R3, and capacitor Includes C0.

[0058] capacitor C0 1st The ends are the cathode of diode D1, the anode of diode D2, and the 1st and the gate of Sense IGBT1b. capacitor C0 Second The end of resistor R3 Second The other configurations are the same as in FIG.

[0059] In the semiconductor device 1-6 as described above, in the voltage control circuit 1c-6, a bidirectional diode including diodes D1 and D2 is disposed between the gate of the main IGBT 1a and the gate of the sense IGBT 1b, and a resistor R3 is disposed between the gate and the sense emitter of the sense IGBT 1b. capacitor C0 is placed.

[0060] In the configuration of the semiconductor device 1-6, it is also possible to suppress oscillations occurring in the sense current detection signal Vsense during the transient sensing period of the sense current detection signal Vsense. Not only the forward voltage drop across diode D1, By resistor R3 too Because it will further decrease ,difference Furthermore, the gate voltage of the sense IGBT 1b can be reduced. capacitor C0 also has the effect of transferring the charge caused by self-charging to the sense emitter side.

[0061] <Overcurrent protection device> An overcurrent protection device to which the semiconductor device of the present invention is applied will be described below. Fig. 12 shows an example of the configuration of an overcurrent protection device. An overcurrent protection device 10-1 includes an input terminal IN, an output terminal OUT, a power supply terminal VT, and a ground terminal GND.

[0062] A pulse-like control signal output from a microcomputer or the like is input to the input terminal IN. A load 2 is connected to the output terminal OUT. A power supply voltage Vcc is connected to the power supply terminal VT, and ground (GND) is connected to the ground terminal GND.

[0063] Moreover, the overcurrent protection device 10-1 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The control circuit 12 includes a logic circuit 12a and a gate driver 12b.

[0064] The logic circuit 12a receives a control signal input through the input terminal IN and generates a logic signal that turns the main IGBT 1a on or off. The gate driver 12b generates a drive signal s0 that turns the main IGBT 1a on or off based on the logic signal output from the logic circuit 12a and applies the drive signal s0 to the gate of the main IGBT 1a.

[0065] The resistor Rs is connected between the sense emitter of the sense IGBT 1b and the emitter of the main IGBT 1a, and detects the potential generated when a sense current flowing from the sense emitter flows through the resistor Rs, thereby detecting the sense current as a sense current detection signal Vsense.

[0066] The overcurrent detection circuit 11 detects whether the main IGBT 1a is in an overcurrent state by comparing the sense current detection signal Vsense with a reference voltage, and outputs an overcurrent detection signal s1 if an overcurrent state is detected. When the logic circuit 12a detects the overcurrent detection signal s1, it turns off the main IGBT 1a.

[0067] 2 can suppress oscillation of the sense current detection signal Vsense, thereby preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection. Although not shown in the figure, the charging-side diode D1 may be configured in multiple stages in series as described above in FIG.

[0068] 13 is a diagram showing an example of the configuration of an overcurrent protection device. The overcurrent protection device 10-2 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-2, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The overcurrent protection device 10-2 is an application of the semiconductor device 1-2 in FIG. 4. The overcurrent protection device 10-2 can also suppress oscillation of the sense current detection signal Vsense, preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection.

[0069] FIG. 14 is a diagram showing an example of the configuration of an overcurrent protection device. The overcurrent protection device 10-3 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-3, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The overcurrent protection device 10-3 is an application of the semiconductor device 1-3 of FIG. 8. The overcurrent protection device 10-3 can also suppress oscillation of the sense current detection signal Vsense, preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection.

[0070] FIG. 15 is a diagram showing an example of the configuration of an overcurrent protection device. The overcurrent protection device 10-4 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-4, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The overcurrent protection device 10-4 is an application of the semiconductor device 1-4 in FIG. 9. The overcurrent protection device 10-4 can also suppress oscillation of the sense current detection signal Vsense, preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection.

[0071] FIG. 16 is a diagram showing an example of the configuration of an overcurrent protection device. The overcurrent protection device 10-5 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-5, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The overcurrent protection device 10-5 is an application of the semiconductor device 1-5 of FIG. 10. The overcurrent protection device 10-5 can also suppress oscillation of the sense current detection signal Vsense, preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection.

[0072] 17 is a diagram showing an example of the configuration of an overcurrent protection device. The overcurrent protection device 10-6 includes a main IGBT 1a, a sense IGBT 1b, a voltage control circuit 1c-6, a resistor Rs, an overcurrent detection circuit 11, and a control circuit 12. The overcurrent protection device 10-6 is an application of the semiconductor device 1-6 of FIG. 11. The overcurrent protection device 10-6 can also suppress oscillation of the sense current detection signal Vsense, preventing malfunction of the overcurrent detection circuit 11 due to oscillation and enabling highly accurate overcurrent detection and protection.

[0073] As described above, according to the present invention, it is possible to suppress oscillations occurring in the sense current detection signal output from the current monitoring power semiconductor element. Furthermore, since oscillations can be effectively suppressed using passive components with a small number of elements, a complex circuit for detecting and controlling oscillations is not required, and an increase in circuit size is also suppressed.

[0074] Although the embodiments have been described above, the configuration of each part shown in the embodiments can be replaced with other parts having similar functions. Also, any other components or processes may be added. Furthermore, any two or more configurations (features) of the above-described embodiments may be combined.

[0075] The foregoing merely illustrates the principles of the present invention. Further, since numerous modifications and changes will be apparent to those skilled in the art, the present invention is not limited to the exact construction and application shown and described above, and all corresponding modifications and equivalents are deemed to be within the scope of the present invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0076] 1. Semiconductor device 1a Output element (main IGBT) 1b Current monitor element (sense IGBT) 1c Voltage control circuit D1 First diode D2 Second diode 2. Load s0 drive signal G Terminal connected to the gate of the output element C Terminal connected to the collector of the output element and current monitor element E Terminal connected to the emitter of the output element SE Terminal connected to the sense emitter of the current monitor element

Claims

1. an output element that operates a load by switching based on a drive signal; a current monitor element that monitors a current flowing through the output element; a voltage control circuit including a first diode that charges a gate voltage applied to a gate of the current monitoring element and a second diode that discharges the gate voltage, and that controls the gate voltage; an anode of the first diode connected to the gate of the output element and the cathode of the second diode, and a cathode of the first diode connected to the anode of the second diode and the gate of the current monitoring element; the voltage control circuit further includes a capacitor, a first end of the capacitor being connected to the cathode of the first diode, the anode of the second diode, and the gate of the current monitoring element, and a second end of the capacitor being connected to the emitter of the output element. Semiconductor device.

2. The output element and the current monitor element are power semiconductor elements, and are one of an IGBT (Insulated Gate Bipolar Transistor), an RC (Reverse Conducting)-IGBT, and a SiC (Silicon carbide) device. The semiconductor device according to claim 1.

3. The power supply further includes a current detection resistor that outputs a sense current output from the current monitor element as a voltage sense current detection signal, and an overcurrent detection circuit that detects an overcurrent state of the output element by comparing the sense current detection signal with a reference voltage. The semiconductor device according to claim 1.

4. a sense emitter of the current monitoring element is connected to a first end of the current detection resistor and an input end of the overcurrent detection circuit; a collector of the output element is connected to the collector of the current monitor element and to a power supply voltage; the emitter of the output element is connected to the second end of the current detection resistor and the load; 4. The semiconductor device according to claim 3.

5. the first diode included in the voltage control circuit is formed by connecting a plurality of diodes in series; The semiconductor device according to claim 1.

6. an output element that operates a load by switching based on a drive signal; a current monitor element that monitors a current flowing through the output element; a voltage control circuit including a first diode that charges a gate voltage applied to a gate of the current monitoring element and a second diode that discharges the gate voltage, and that controls the gate voltage; an anode of the first diode connected to the gate of the output element and the cathode of the second diode, and a cathode of the first diode connected to the anode of the second diode and the gate of the current monitoring element; the voltage control circuit further includes a voltage divider circuit including a first resistor and a second resistor, a first end of the first resistor connected to the anode of the first diode, the cathode of the second diode, and the gate of the output element, a second end of the first resistor connected to the cathode of the first diode, the anode of the second diode, the first end of the second resistor, and the gate of the current monitoring element, and a second end of the second resistor connected to the sense emitter of the current monitoring element; the voltage control circuit further includes a capacitor, a first end of the capacitor connected to the cathode of the first diode, the anode of the second diode, the second end of the first resistor, and the gate of the current monitoring element, and a second end of the capacitor connected to the second end of the second resistor and the sense emitter of the current monitoring element. Semiconductor device.

7. an output element that operates a load by switching based on a drive signal; a current monitor element that monitors a current flowing through the output element; a voltage control circuit including a first diode that charges a gate voltage applied to a gate of the current monitoring element and a second diode that discharges the gate voltage, and that controls the gate voltage; an anode of the first diode connected to the gate of the output element and the cathode of the second diode, and a cathode of the first diode connected to the anode of the second diode and the gate of the current monitoring element; the voltage control circuit further includes a resistor, a first end of the resistor being connected to the cathode of the first diode, the anode of the second diode, and the gate of the current monitoring element, and a second end of the resistor being connected to the sense emitter of the current monitoring element; the voltage control circuit further includes a capacitor, a first end of the capacitor being connected to the cathode of the first diode, the anode of the second diode, the first end of the resistor, and the gate of the current monitoring element, and a second end of the capacitor being connected to the second end of the resistor and the sense emitter of the current monitoring element. Semiconductor device.

8. An output element that switches based on a drive signal to operate a load; a current monitor element that monitors a current flowing through the output element; a voltage control circuit including a first diode that charges a gate voltage applied to a gate of the current monitoring element and a second diode that discharges the gate voltage, and that controls the gate voltage; an anode of the first diode connected to the gate of the output element and the cathode of the second diode, and a cathode of the first diode connected to the anode of the second diode and the gate of the current monitoring element; the voltage control circuit further includes a resistor, a first end of the resistor being connected to the cathode of the first diode, the anode of the second diode, and the gate of the current monitoring element, and a second end of the resistor being connected to the sense emitter of the current monitoring element. Semiconductor device.

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