JP7086290B2 - Semiconductor drive - Google Patents

Description

The present invention relates to a semiconductor drive device.

In a power converter that drives a plurality of semiconductor elements, voltage fluctuations or noise currents generated by the switching operation of the semiconductor element may cause a malfunction of a drive circuit of another semiconductor element. For example, when a power source for driving a plurality of semiconductor elements is common, noise may sneak into another semiconductor element via the common power source. Conventionally, a drive device having measures to prevent such a problem has been known.

For example, the inverter drive circuit described in Patent Document 1 is inserted in an electric circuit connecting a gate drive circuit connected to each semiconductor element connected to the inverter negative electrode side arm and a common power supply unit for the gate drive circuit. Includes multiple reactors that have been made.

In the inverter drive circuit described in Patent Document 1, the reactor can suppress the AC component of the current accompanying the switching operation of the semiconductor element from wrapping around to another semiconductor element.

Jitsukaihei 03-003190 Gazette

However, the inverter drive circuit described in Patent Document 1 cannot suppress the DC component of the current accompanying the switching operation of the semiconductor element from wrapping around to another semiconductor element.

Therefore, an object of the present invention is to provide a semiconductor drive device capable of suppressing the wraparound of a current due to a switching operation of a semiconductor element to another semiconductor element not only for an AC component but also for a DC component.

The semiconductor drive device of the present invention is a semiconductor drive device that drives a first semiconductor element and a second semiconductor element, and includes a first drive unit connected to a negative electrode and a control electrode of the first semiconductor element. A common positive including a second drive unit connected to the negative electrode and the control electrode of the second semiconductor element, a first end connected to the reference potential, and a second end having a positive potential with respect to the reference potential. It includes a power supply, a reference power supply line connected to the reference potential side of the common positive power supply, and a positive power supply line connected to the positive potential side of the common positive power supply. Each of the first drive unit and the second drive unit is connected between the positive power supply line and the reference power supply line with the drive circuit that controls the potential of the control electrode of the first semiconductor element or the second semiconductor element. A first having a first capacitor inserted in a positive power supply line, a first end connected to the positive electrode of the first capacitor, and a second end connected to a second end of a common positive power supply. And a second element having a first end inserted into the reference power supply line and connected to the negative electrode of the first capacitor, and a second end connected to the first end of the common positive power supply. Be prepared. The negative electrode of the first semiconductor element and the negative electrode of the second semiconductor element are connected to each other. The first element and the second element are diodes connected in a direction capable of passing a charging current from a resistance element or a common positive power source to the first capacitor. At least one of the first element and the second element is a resistance element.

The semiconductor drive device of the present invention includes a first element inserted in the positive power supply line and a second element inserted in the reference power supply line. The first element and the second element are diodes connected in a direction capable of passing a charging current from a resistance element or a common positive power source to the first capacitor. At least one of the first element and the second element is a resistance element. As a result, it is possible to suppress the wraparound of the current to another semiconductor element due to the switching operation of the semiconductor element not only for the AC component but also for the DC component.

It is a figure which shows the structure of the semiconductor drive device 10 of Embodiment 1. FIG. It is a figure which shows the structure of the semiconductor drive apparatus 10A of Reference Example 1. FIG. It is a figure which shows the structure of the semiconductor drive apparatus 10B of a reference example 2. FIG. It is a figure which shows the structure of the semiconductor drive apparatus 10C of Reference Example 3. FIG. It is a figure which shows the example of the current waveform when the 1st semiconductor element 1a is driven by the semiconductor drive apparatus 10 of Embodiment 1. FIG. It is a figure which shows the example of the current waveform at the time of driving the 1st semiconductor element 1a by using the semiconductor drive apparatus 10A of Reference Example 1. FIG. It is a figure which shows the example of the current waveform at the time of driving the 1st semiconductor element 1a by using the semiconductor drive apparatus 10B of Reference Example 2. FIG. It is a figure which shows the structure of the semiconductor drive device 10D of Embodiment 2. It is a figure which shows the voltage of the capacitor 3a of the semiconductor drive device of Embodiment 3. FIG. It is a figure which shows the structure of the semiconductor drive device 10E of Embodiment 4. It is a figure which shows the structure of the semiconductor drive device 10F of Embodiment 5. It is a figure which shows the structure of the semiconductor drive device 10G of Embodiment 6. It is a figure which shows the structure of the semiconductor drive device 10H of Embodiment 7. It is a figure which shows the structure of the semiconductor drive device 10I of Embodiment 8.

Hereinafter, embodiments will be described with reference to the drawings.
Embodiment 1.
FIG. 1 is a diagram showing the configuration of the semiconductor drive device 10 of the first embodiment.

The semiconductor drive device 10 drives the first semiconductor element 1a and the second semiconductor element 1b. The negative electrode of the first semiconductor element 1a and the negative electrode of the second semiconductor element 1b are connected.

The semiconductor drive device 10 includes a first drive unit 100a, a second drive unit 100b, a common positive power supply 6, a reference power supply line 51, and a positive power supply line 61.

The first drive unit 100a and the second drive unit 100b are connected to the control electrode and the negative electrode of the first semiconductor element 1a and the second semiconductor element 1b, respectively.

The first end of the common positive power supply 6 is connected to the reference potential 5, and the second end of the common positive power supply 6 has a positive potential with respect to the reference potential 5. The reference power supply line 51 connects the first end of the common positive power supply 6, the first drive unit 100a, and the second drive unit 100b. The positive power supply line 61 connects the second end of the common positive power supply 6, the first drive unit 100a, and the second drive unit 100b.

The first drive unit 100a includes a drive circuit 2a, a capacitor 3a, a resistance element 62a, and a resistance element 52a.

The drive circuit 2a is connected to the positive power supply line 61 and the reference power supply line 51. The drive circuit 2a controls the potential of the control electrode of the first semiconductor element 1a.

The positive electrode of the capacitor 3a is connected to the positive power supply line 61. The negative electrode of the capacitor 3b is connected to the reference power supply line 51.

The resistance element 62a is inserted in the positive power supply line 61. The resistance element 62a has a first end connected to the positive electrode of the capacitor 3a and a second end connected to the second end of the common positive power supply 6.

The resistance element 52a is inserted in the reference power supply line 51. The resistance element 52a has a first end connected to the negative electrode of the capacitor 3a and a second end connected to the first end of the common positive power supply 6.

The second drive unit 100b includes a drive circuit 2b, a capacitor 3b, a resistance element 62b, and a resistance element 52b.

The drive circuit 2b is connected to the positive power supply line 61 and the reference power supply line 51. The drive circuit 2b controls the potential of the control electrode of the second semiconductor element 1b.

The positive electrode of the capacitor 3b is connected to the positive power supply line 61. The negative electrode of the capacitor 3b is connected to the reference power supply line 51.

The resistance element 62b is inserted in the positive power supply line 61. The resistance element 62b has a first end connected to the positive electrode of the capacitor 3b and a second end connected to the second end of the common positive power supply 6.

The resistance element 52b is inserted in the reference power supply line 51. The resistance element 52b has a first end connected to the negative electrode of the capacitor 3b and a second end connected to the first end of the common positive power supply 6.

Since the negative electrode of the first semiconductor element 1a and the negative electrode of the second semiconductor element 1b are connected, the semiconductor drive device 10 corresponds to a full bridge circuit. The semiconductor drive device 10 includes, but is not limited to, a pair of first semiconductor elements 1a, a first drive unit 100a connected to a second semiconductor element 1b, and a second drive unit 100b. .. The semiconductor drive device may include three or more drive units. When the semiconductor drive device includes three drive units, the semiconductor drive device corresponds to a three-phase inverter circuit. The positive electrodes of two or more semiconductor elements may be connected to each other, and each of the plurality of driving units may individually drive the corresponding semiconductor element.

Next, the first semiconductor element 1a and the first drive unit 100a connected to the first semiconductor element 1a will be described. The second drive unit 100b is also the same as the first drive unit 100a.

The control electrode of the first semiconductor element 1a is connected to the drive circuit 2a, and the drive circuit 2a drives the first semiconductor element 1a.

The first semiconductor element 1a is, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), a HEMT (High Electron Mobility Transistor), or the like. As the material of the first semiconductor device 1a, "Si", "SiC", "GaN" and the like can be applied.

The drive circuit 2a controls the open / closed state of the first semiconductor element 1a by controlling the potential of the control electrode of the first semiconductor element 1a.

The capacitor 3a is connected in parallel to the drive circuit 2a and functions as a power source for the drive circuit 2a. The capacitor 3a receives power from the common positive power supply 6 via the resistance element 52a and the resistance element 62a. When the resistance of the resistance element 52a is R52a and the resistance of the resistance element 62a is R62a, the combined resistance R1a [Ω] of the resistance element 52a and the resistance element 62a is represented by (R52a + R62a). Let the capacitance of the capacitor 3a be C1a [F]. The charging time constant τ1a of the capacitor 3a can be expressed as R1a × C1a [s]. When the drive cycle of the first semiconductor element 1a is Ta [s], the drive condition of the first semiconductor element 1a is that the charging time constant τ1a is smaller than the drive cycle Ta (R1a × C1a <Ta). Thereby, it is possible to drive the first semiconductor element 1a while maintaining the voltage of the capacitor 3a. As a result, the first semiconductor element 1a can be driven normally. However, in a drive circuit such as a bootstrap circuit in which the voltage of the capacitor 3a increases or decreases from the original value, in the case of a circuit design that allows a certain decrease in the voltage of the capacitor 3a, such a drive condition is satisfied. It does not have to be provided.

The negative electrodes of the first semiconductor element 1a and the second semiconductor element 1b are connected to each other, and the first drive unit 100a and the second drive unit 100b pass through the reference power supply line 51 and the positive power supply line 61. Connected to each other. In such a circuit configuration, the current Id flowing from the positive electrode side of the first semiconductor element 1a is shunted into the main current Is flowing in a load such as a motor and the shunt current Iss. In FIG. 1, the shunt current Iss flows through the current path RA that sequentially passes through the resistance element 52a and the resistance element 52b of the reference power supply line 51. Another shunt current Iss2 flows through the current path RB that passes through the capacitor 3a, the resistance element 62a, the resistance element 62b, and the capacitor 3b in this order. Here, the shunt current Iss flowing through the current path RA will be described.

Parasitic resistance and parasitic inductance (not shown) are present in the current paths of the main current Is and the shunt current Iss. When the semiconductor drive device 10 does not take measures against the shunt current Iss, that is, when the resistance elements 52a and 52b are not provided, the main current Is and the shunt current depend on the magnitude relationship between the parasitic resistance and the parasitic inductance. The shunt ratio of Iss is determined.

By using the resistance elements 52a and 52b to make the resistance value of the current path RA of the shunt current Is sufficiently larger than the resistance value of the current path of the main current Is, it is possible to suppress the DC component of the shunt current Is. .. For example, when the shunt ratio of the main current Is and the shunt current Is is set to 100: 1, the resistance element 52a, so that the resistance 100 times the parasitic resistance in the current path of the main current Is occurs in the current path RA of the shunt current Is. The resistance value of 52b may be set. The parasitic resistance of the current path of the main current Is is usually about 0.01 to 1Ω. When the parasitic resistance of the current path of the main current is 0.01 to 1Ω, the resistance value of the current path RA of the shunt current Is is set to 1 to 100Ω by providing the resistance elements 52a and 52b, so that the shunt current is shunted. The DC component of Iss can be suppressed. For example, the combined resistance of the resistance element 52a and the resistance element 52b may be set to 1 to 100Ω.

When the semiconductor drive device 10 includes only the resistance elements 52a and 52b and does not include the resistance elements 62a and 62b, as described above, the diversion current Iss2 flowing through the current path RB passes through the capacitors 3a and 3b. It flows into the second semiconductor element 1b side. The shunt current Iss2 is a current that flows while charging / discharging the capacitors 3a and 3b by the voltage generated in the current path of the main current Is. Therefore, in order to suppress this shunt current Iss2, it is necessary to set the resistance value of the current path RB of the shunt current Is2 to about 1 to 100Ω by the resistance elements 62a and 62b. For example, the combined resistance of the resistance element 62a and the resistance element 62b may be set to 1 to 100Ω.

Next, the semiconductor drive device of the reference example will be described.
FIG. 2 is a diagram showing the configuration of the semiconductor drive device 10A of Reference Example 1.

The semiconductor drive device 10A of Reference Example 1 does not include the resistance elements 52a, 52b, 62a, 62b included in the semiconductor drive device 10 of the first embodiment.

In the semiconductor drive device 10A of Reference Example 1, the current path RA of the shunt current Is and the current path RB of the shunt current Is2 exist as in the semiconductor drive device 10 of FIG. 1, but here, only the current path RA exists. To consider. The shunt ratio between the main current Is and the shunt current Is is determined by the magnitude relationship between the parasitic component of the current path of the main current Is and the shunt component of the current path of the shunt current Is. In recent miniaturized semiconductor devices, a drive circuit 2a, a capacitor 3a, and a common positive power supply 6 are arranged in the vicinity of the first semiconductor element 1a due to high integration. As a result, the size of the parasitic component in the current path of the shunt current Is may be close to the size of the parasitic component in the current path of the main current Is. For example, when the parasitic resistance of the current path of the split current Is is 90 mΩ and the parasitic resistance of the current path of the main current Is is 10 mΩ, if Id = 100 A, the DC component of the main current Is is 90 A and the direct current of the split current Is is DC. The component is 10A. Normally, it is not considered that a current of 10 A is applied to the wiring in the vicinity of the drive circuit 2a, so that the wiring in the vicinity of the drive circuit 2a may be burnt out and the drive circuit 2a may malfunction accordingly.

FIG. 3 is a diagram showing the configuration of the semiconductor drive device 10B of Reference Example 2.
The semiconductor drive device of Reference Example 2 includes inductors 152a, 152b and inductors 162a, 162b in place of the resistance elements 52a, 52b and the resistance elements 62a, 62b included in the semiconductor drive device 10 of the first embodiment.

In the semiconductor drive device 10B of Reference Example 2, the current path RA of the shunt current Is and the current path RB of the shunt current Iss 2 exist as in the semiconductor drive device 10 of FIG. 1, but here, only the current path RA exists. To consider.

In the semiconductor drive device 10B of Reference Example 2, since the inductors 152a and 152b and the inductors 162a and 162b show high resistance values with respect to a high frequency current, during the switching operation of the first semiconductor element 1a and the second semiconductor element 1b. It is possible to suppress the high frequency components of the generated noise current and diversion current Iss.

The impedance Z [Ω] of the inductor can be expressed as Z = 2πfL by using the frequency f [Hz] and the inductance L [H]. When the inductance L is 10 μH, the impedance Z of the inductor is 6.28 × 10 ¹ Ω for the frequency f of 1 MHz, and the impedance Z of the inductor is 6.28 × 10 ⁻ for the frequency f of 1 kHz. It becomes ¹ Ω.

On the other hand, an inductor having an inductance L of 100 μH class has a parasitic resistance of about several Ω. With such an inductor, the effect of suppressing the diversion can be obtained both in terms of direct current and alternating current, but there is a problem that the size of such an inductor is larger than the size of the resistance element.

As described above, the inductors 152a and 152b have a small resistance value with respect to the currents of the low frequency component and the DC component, and the shunt current Iss increases when the current Id is continuously energized. In the case of direct current, the shunt ratio between the main current Is and the shunt current Is is determined by the parasitic resistance of the wiring and the parasitic resistance of the inductors 152a and 152b. Further, when a current flows through the inductors 152a and 152b, energy is stored in the inductors 152a and 152b, which may adversely affect the current cutoff of the first semiconductor element 1a and the second semiconductor element 1b. Further, resonance occurs between the inductors 152a and 152b and the capacitors 3a and 3b, and the voltage increases or decreases, which may adversely affect the driving of the first semiconductor element 1a and the second semiconductor element 1b. be.

FIG. 4 is a diagram showing the configuration of the semiconductor drive device 10C of Reference Example 3.
The semiconductor drive device 10C of Reference Example 3 includes diodes 252a, 252b and diodes 262a, 262b in place of the resistance elements 52a, 52b and the resistance elements 62a, 62b included in the semiconductor drive device 10 of the first embodiment. ..

The diodes 252a and 252b and the diodes 262a and 262b are connected from the common positive power supply 6 in a direction in which a charging current can be applied to the capacitors 3a and 3b.

In the semiconductor drive device 10C of Reference Example 3, the shunt current of the current path passing through the diodes 262a and 252b can be suppressed. However, when the common positive power supply 6 and the capacitor 3b are energized by the electromotive voltage due to the parasitic component of the current path of the main current Is, the voltage of the capacitor 3b fluctuates, which adversely affects the drive of the second semiconductor element 1b. there is a possibility.

Next, the effect of suppressing the shunt current Iss of the present embodiment will be described.
FIG. 5 is a diagram showing an example of a current waveform when the first semiconductor element 1a is driven by the semiconductor driving device 10 of the first embodiment.

The current waveform when the first semiconductor element 1a is turned on at time t = 0 is shown. After the turn-on of the first semiconductor element 1a, the magnitudes of the current Id and the main current Is are the same, and the shunt current Is is not flowing. Therefore, in this embodiment, it is shown that suppression of the shunt current Iss is effective.

FIG. 6 is a diagram showing an example of a current waveform when the first semiconductor element 1a is driven by using the semiconductor driving device 10A of Reference Example 1.

The current waveform when the first semiconductor element 1a is turned on at time t = 0 is shown. At the turn-on timing of the first semiconductor element 1a, the shunt current Iss transiently becomes about 1/10 of the magnitude of the current Id. Therefore, in Reference Example 1, suppression of the shunt current Iss is not effective.

FIG. 7 is a diagram showing an example of a current waveform when the first semiconductor element 1a is driven by using the semiconductor driving device 10B of Reference Example 2.

The current waveform when the first semiconductor element 1a is turned on at time t = 0 is shown. Since the high-frequency current is suppressed by the inductors 152a and 162a, the shunt current Iss can be suppressed at the turn-on timing of the first semiconductor element 1a. On the other hand, since the inductors 152 and 162a have a small resistance value with respect to the current of the DC component, the shunt current Iss increases with the passage of time. Therefore, in Reference Example 2, the effect of suppressing the shunt current Iss is reduced.

In the above, the size of the first semiconductor element 1a and the second semiconductor element 1b are the same, the sizes of the resistance elements 52a, 52b, 62a and 62b are the same, the capacities of the capacitors 3a and 3b are the same, and the first semiconductor element. The drive cycles of 1a and the second semiconductor element 1b may be the same. Thereby, the drive characteristics of the first semiconductor element 1a and the second semiconductor element 1b can be made the same.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. A part of the divergent current of the current flowing through the second semiconductor element 1b flows through the path passing through the resistance element 52b and the resistance element 52a of the reference power supply line 51 in order, and another part is the capacitor 3b and the resistance element. It flows through a path that passes through 62b, a resistance element 62a, and a capacitor 3a in this order.

When the resistance of the resistance element 52b is R52b and the resistance of the resistance element 62b is R62b, the combined resistance R1b [Ω] of the resistance element 52b and the resistance element 62b is represented by (R52b + R62b). Let the capacitance of the capacitor 3b be C1b [F]. The charging time constant τ1b of the capacitor 3b can be expressed as R1b × C1b [s]. When the drive cycle of the second semiconductor element 1b is Tb [s], the drive condition of the second semiconductor element 1b is that the charging time constant τ1b is smaller than the drive cycle Tb (Rb1 × Cb1 <Tb). Thereby, it is possible to drive the second semiconductor element 1b while maintaining the voltage of the capacitor 3b. As a result, the second semiconductor element 1b can be driven normally. However, in a drive circuit such as a bootstrap circuit in which the voltage of the capacitor 3b increases or decreases from the original value, in the case of a circuit design that allows a certain decrease in the voltage of the capacitor 3b, such a drive condition is applied. It does not have to be provided.

As described above, according to the first embodiment, the diversion current Iss that the resistance elements 52a and 52b and the resistance elements 62a and 62b wrap around from the first semiconductor element 1a or the second semiconductor element 1b to the other drive circuit side. Can be suppressed. Further, according to the first embodiment, the charging time constants τ1a and τ1b of the capacitors 3a and 3b are made smaller with respect to the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b, thereby making the capacitors. The first semiconductor element 1a and the second semiconductor element 1b can be driven while maintaining the voltages of 3a and 3b. Further, according to the first embodiment, the semiconductor drive device can be downsized by using the resistance elements 52a, 52b, 62a, 62b without using a large inductor. Further, according to the first embodiment, it is possible to suppress the burning of the wiring due to the shunt current, the malfunction of the peripheral circuit, the voltage fluctuation, and the like, so that the reliability of driving the semiconductor element is improved.

Embodiment 2.
FIG. 8 is a diagram showing the configuration of the semiconductor drive device 10D according to the second embodiment.

The semiconductor drive device 10D drives the first semiconductor element 1a and the second semiconductor element 1b. The negative electrode of the first semiconductor element 1a and the negative electrode of the second semiconductor element 1b are connected.

The semiconductor drive device 10D includes a first drive unit 100a, a second drive unit 100b, a common positive power supply 6, a common negative power supply 7, a reference power supply line 51, a positive power supply line 61, and a negative power supply line 71. And prepare.

The first drive unit 100a and the second drive unit 100b are connected to the control electrode and the negative electrode of the first semiconductor element 1a and the second semiconductor element 1b, respectively.

The first end of the common positive power supply 6 is connected to the reference potential 5, and the second end of the common positive power supply 6 has a positive potential with respect to the reference potential 5. The first end of the common negative power source 7 is connected to the reference potential 5, and the second end of the common negative power source 7 has a negative potential with respect to the reference potential 5. The reference power supply line 51 connects the first end of the common positive power supply 6 and the first end of the common negative power supply 7 with the first drive unit 100a and the second drive unit 100b. The positive power supply line 61 connects the second end of the common positive power supply 6, the first drive unit 100a, and the second drive unit 100b. The negative power supply line 71 connects the second end of the common negative power supply 7, the first drive unit 100a, and the second drive unit 100b.

The first drive unit 100a includes a drive circuit 2a, a capacitor 3a, a capacitor 4a, a resistance element 62a, a resistance element 52a, and a resistance element 72a.

The drive circuit 2a is connected to the positive power supply line 61 and the negative power supply line 71. The drive circuit 2a controls the potential of the control electrode of the first semiconductor element 1a.

The positive electrode of the capacitor 3a is connected to the positive power supply line 61. The negative electrode of the capacitor 3b is connected to the reference power supply line 51.

The positive electrode of the capacitor 4a is connected to the reference power supply line 51. The negative electrode of the capacitor 4b is connected to the negative power supply line 71.

The resistance element 62a is inserted in the positive power supply line 61. The resistance element 62a has a first end connected to the positive electrode of the capacitor 3a and a second end connected to the second end of the common positive power supply 6.

The resistance element 52a is inserted in the reference power supply line 51. The resistance element 52a has a first end connected to the negative electrode of the capacitor 3a and the positive electrode of the capacitor 4a, and a second end connected to the first end of the common positive power supply 6 and the first end of the common negative power supply 7. ..

The resistance element 72a is inserted in the negative power supply line 71. The resistance element 72a has a first end connected to the negative electrode of the capacitor 4a and a second end connected to the second end of the common negative power source 7.

The drive circuit 2b is connected to the positive power supply line 61 and the negative power supply line 71. The drive circuit 2b controls the potential of the control electrode of the second semiconductor element 1b.

The positive electrode of the capacitor 3b is connected to the positive power supply line 61. The negative electrode of the capacitor 3b is connected to the reference power supply line 51.

The positive electrode of the capacitor 4b is connected to the reference power supply line 51. The negative electrode of the capacitor 4b is connected to the negative power supply line 71.

The resistance element 62b is inserted in the positive power supply line 61. The resistance element 62b has a first end connected to the positive electrode of the capacitor 3b and a second end connected to the second end of the common positive power supply 6.

The resistance element 52b is inserted in the reference power supply line 51. The resistance element 52b has a first end connected to the negative electrode of the capacitor 3b and the positive electrode of the capacitor 4b, and the other end connected to the first end of the common positive power supply 6 and the first end of the common negative power supply 7.

The resistance element 72b is inserted in the negative power supply line 71. The resistance element 72b has a first end connected to the negative electrode of the capacitor 4b and a second end connected to the second end of the common negative power source 7.

According to the circuit configuration, in addition to the configuration of the semiconductor drive device of the first embodiment, capacitors 4a and 4b, a common negative power supply 7, a negative power supply line 71, and resistance elements 72a and 72b are provided.

In addition to the current paths RA and RB described in the first embodiment, the shunt current path of the second embodiment includes the current path RD through which the shunt current Is3 flows.

The current path RD is a path that sequentially passes through the capacitor 4a, the resistance element 72a, the resistance element 72b, and the capacitor 4b. By providing the resistance elements 72a and 72b, the resistance element exists in the current path RD, and the shunt current Iss3 can be suppressed. In the present embodiment, the resistance value of the current path RD of the shunt current Is3 is set to about 1 to 100Ω by the resistance elements 72a and 72b. For example, the combined resistance of the resistance element 72a and the resistance element 72b may be set to 1 to 100Ω.

When the resistance of the resistance element 52a is R52a, the resistance of the resistance element 62a is R62a, and the resistance of the resistance element 72a is R72a, the combined resistance R1a [Ω] of the resistance element 52a and the resistance element 62a is represented by (R52a + R62a). , The combined resistance R2a [Ω] of the resistance element 52a and the resistance element 72a is represented by (R52a + R72a). Let the capacitance of the capacitor 3a be C1a [F] and the capacitance of the capacitor 4a be C2a [F]. The drive cycle of the first semiconductor device 1a is Ta [s]. The charging time constant τ1a of the capacitor 3a can be expressed as R1a × C1a [s]. By setting the charging time constant τ1a to be smaller than the drive cycle Ta of the first semiconductor element 1a (R1a × C1a <Ta) as the drive condition of the first semiconductor element 1a, the voltage of the capacitor 3a is maintained. It is possible to drive the semiconductor element 1a of 1. The charging time constant τ2a of the capacitor 4a can be expressed as R2a × C2a [s]. By setting the charging time constant τ2a to be smaller than the drive cycle Ta of the first semiconductor element 1a (R2a × C2a <Ta) as the drive condition of the first semiconductor element 1a, the voltage of the capacitor 4a is maintained. It is possible to drive the semiconductor element 1a of 1. As a result, the first semiconductor element 1a can be driven normally. However, in the case of a drive circuit such as a bootstrap circuit in which the voltage of the capacitors 3a and 4a increases and decreases from the original value, in the case of a circuit design that can tolerate a certain decrease in the voltage of the capacitors 3a and 4a, such a case is used. It is not necessary to set various driving conditions.

In the above, the sizes of the first semiconductor element 1a and the second semiconductor element 1b are the same, the sizes of the resistance elements 52a, 52b, 62a, 62b, 72a, 72b are the same, and the capacities of the capacitors 3a, 3b, 4a, 4b. May be the same, and the drive cycles of the first semiconductor element 1a and the second semiconductor element 1b may be the same. Thereby, the drive characteristics of the first semiconductor element 1a and the second semiconductor element 1b can be made the same.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same.

A part of the shunt current of the current flowing through the second semiconductor element 1b flows through a path that sequentially passes through the resistance element 52b and the resistance element 52a of the reference power supply line 51. Another portion of the shunt current flows through a path that sequentially passes through the capacitor 3b, the resistance element 62b, the resistance element 62a, and the capacitor 3a. Yet another portion of the shunt current flows through a path that passes through the capacitor 4b, the resistance element 72b, the resistance element 72a, and the capacitor 4a in that order.

When the resistance of the resistance element 52b is R52b, the resistance of the resistance element 62b is R62b, and the resistance of the resistance element 72b is R72b, the combined resistance R1b [Ω] of the resistance element 52b and the resistance element 62b is represented by (R52b + R62b). , The combined resistance R2b [Ω] of the resistance element 52b and the resistance element 72b is represented by (R52b + R72b). Let the capacitance of the capacitor 3b be C1b [F] and the capacitance of the capacitor 4b be C2b [F]. The drive cycle of the second semiconductor element 1b is Tb [s]. The charging time constant τ1b of the capacitor 3b can be expressed as Rb1 × C1b [s]. By setting the charging time constant τ1b to be smaller than the drive cycle Tb (R1b × C1b <Tb) as the driving condition of the second semiconductor element 1b, the second semiconductor element 1b is driven while maintaining the voltage of the capacitor 3b. It is possible to do. The charging time constant τ2b of the capacitor 4b can be expressed as R2b × C2b [s]. By setting the charging time constant τ2b to be smaller than the drive cycle Tb (R2b × C2b <Tb) as the driving condition of the second semiconductor element 1b, the second semiconductor element 1b is driven while maintaining the voltage of the capacitor 4b. It is possible to do. As a result, the second semiconductor element 1b can be driven normally. However, in the case of a drive circuit such as a bootstrap circuit in which the voltage of the capacitors 3b and 4b increases and decreases from the original value, in the case of a circuit design that can tolerate a certain decrease in the voltage of the capacitors 3b and 4b, such a case is used. It is not necessary to set various driving conditions.

As described above, according to the second embodiment, even in the configuration in which the semiconductor drive device 10D includes the common negative power supply 7 in addition to the common positive power supply 6, the resistance elements 52a, 52b, 62a, 62b, 72a, 72b are used. , The shunt current Iss that wraps around from the first semiconductor element 1a or the second semiconductor element 1b via the other drive circuit can be suppressed. Further, the charging time constants τ1a and τ2a of the capacitors 3a and 4a are reduced with respect to the drive cycle Ta of the first semiconductor element 1a, and the capacitors 3b and 4b are charged with respect to the drive cycle Tb of the second semiconductor element 1b. By reducing the constants τ1b and τ2b, the capacitors 3a, 3b, 4a and 4b can be driven while maintaining their voltages. Furthermore, by using a resistance element, it is possible to miniaturize the drive circuit without using a large inductor, and it suppresses wiring burnout due to shunt current, malfunction of peripheral circuits, voltage fluctuation, etc., and improves drive reliability. Can be driven.

Embodiment 3.
The semiconductor drive device according to the third embodiment is different from the semiconductor drive device according to the first embodiment in that at least one of the following (a) and (b) is satisfied. (A) The charging time constant τ1a of the capacitor 3a is larger than the drive cycle Ta of the first semiconductor element 1a, and (b) the charging time constant τ1b of the capacitor 3b is larger than the drive cycle Tb of the second semiconductor element 1b. In such a case, the voltage of at least one of the capacitors 3a or 3b is reduced. When the drive voltage of the first semiconductor element 1a or the second semiconductor element 1b decreases as a result of the decrease in the voltage of the capacitor 3a or 3b, the switching operation of the first semiconductor element 1a or the second semiconductor element 1b becomes impossible. Or the switching speed is reduced. In this embodiment, such a problem is solved.

Hereinafter, a case where the charging time constant τ1a of the capacitor 3a is larger than the drive period Ta of the first semiconductor element 1a will be described.

FIG. 9 is a diagram showing the voltage of the capacitor 3a of the semiconductor drive device according to the third embodiment.
In the steady state in which the first semiconductor element 1a is continuously driven, the voltage of the capacitor 3a stabilizes at a certain voltage Vx reduced from the initial voltage Vi. The initial voltage Vi is the voltage of the common positive power supply 6. The voltage Vx can be calculated from the condition that the voltage component charged from the common positive power supply 6 and the voltage component consumed by driving the first semiconductor element 1a match.

When the first semiconductor element 1a is turned on once, the amount of charge for charging the control electrode of the first semiconductor element 1a is defined as Qga [C]. The charge amount Qga is also the charge amount discharged from the control electrode of the first semiconductor element 1a when the first semiconductor element 1a is turned off once. The capacitance of the capacitor 3a is C1a [F], and the combined resistance of the resistance element 52a and the resistance element 62a existing in the current path for charging the capacitor 3a is R1a [Ω].

The voltage of the capacitor 3a, which decreases with one turn-on of the first semiconductor element 1a, can be expressed as Qga / C1a [V]. On the other hand, the capacitor 3a is charged from the current voltage Vx [V] to the initial voltage Vi [V] with a charging time constant τ1a (= R1a × C1a [s]). The voltage charged during the drive cycle Ta of the first semiconductor element 1a can be expressed by the following mathematical formula (1).

Therefore, the following mathematical formula (2) can be obtained from the condition that the voltage component charged and the voltage component consumed during the drive cycle Ta of the first semiconductor element 1a match. By solving the equation (2), the voltage Vx [V] of the capacitor 3a, which is stable in the steady state, can be expressed by the following equation (3).

If the voltage Vx [V] changes by 1 [V] or more with respect to the initial voltage Vi [V], it also affects the driving conditions of the first semiconductor element 1a, so the change is less than 1 [V]. It is desirable to be. 1 [V] means that the voltage Vi of the common positive power supply 6 is about 10 to 20 V, and when the drive voltage of the first semiconductor element 1a changes by about 10%, the switching operation of the first semiconductor element 1a This is because the effect on is not negligible.

By selecting a capacitor 3a having a capacitance C1a satisfying the following formula (4) from these conditions, and a resistance element 62a and a resistance element 52a having a combined resistance R1a, the drive voltage of the first semiconductor element 1a can be increased. The diversion current can be suppressed without decreasing.

When the charging time constant τ1b of the capacitor 3b is larger than the drive cycle Tb of the second semiconductor element 1b, the control electrode of the second semiconductor element 1b is charged when the second semiconductor element 1b is turned on once. Let Qgb [C] be the amount of charge to be applied. The charge amount Qgb is also the charge amount discharged from the control electrode of the second semiconductor element 1b when the second semiconductor element 1b is turned off once. The capacitance of the capacitor 3b is C1b [F], and the combined resistance of the resistance element 52b and the resistance element 62b existing in the current path for charging the capacitor 3b is R1b [Ω].

By selecting the capacitor 3b having the capacitance C1b satisfying the following formula (5), and the resistance element 62b and the resistance element 52b having the combined resistance R1b, the drive voltage of the second semiconductor element 1b does not decrease. , The diversion current can be suppressed.

According to the third embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the third embodiment.
The conditions set in the third embodiment are also valid for the semiconductor drive device of the second embodiment.

When the charging time constant τ2a of the capacitor 4a is larger than the drive cycle Ta of the first semiconductor element 1a, the control electrode of the first semiconductor element 1a is charged when the first semiconductor element 1a is turned on once. Let Qga [C] be the amount of charge to be applied. The charge amount Qga is also the charge amount discharged from the control electrode of the first semiconductor element 1a when the first semiconductor element 1a is turned off once. The capacitance of the capacitor 4a is C2a [F], and the combined resistance of the resistance element 52a and the resistance element 72a existing in the current path for charging the capacitor 4a is R2a [Ω].

By selecting the capacitor 4a having the capacitance C2a satisfying the following formula (6), and the resistance element 52a and the resistance element 72a having the combined resistance R2a, the drive voltage of the first semiconductor element 1a does not decrease. , The diversion current can be suppressed.

When the charging time constant τ2b of the capacitor 4b is larger than the drive cycle Tb of the second semiconductor element 1b, the control electrode of the second semiconductor element 1b is charged when the second semiconductor element 1b is turned on once. Let Qgb [C] be the amount of charge to be applied. The charge amount Qgb is also the charge amount discharged from the control electrode of the second semiconductor element 1b when the second semiconductor element 1b is turned off once. The capacitance of the capacitor 4b is C2b [F], and the combined resistance of the resistance element 52b and the resistance element 72b existing in the current path for charging the capacitor 4b is R2b [Ω].

By selecting the capacitor 4b having the capacitance C2b satisfying the following formula (7), and the resistance element 52b and the resistance element 72b having the combined resistance R2b, the drive voltage of the second semiconductor element 1b does not decrease. , The diversion current can be suppressed.

Embodiment 4.
FIG. 10 is a diagram showing the configuration of the semiconductor drive device 10E according to the fourth embodiment.

The semiconductor drive device 10E according to the fourth embodiment includes diodes 252a and 252b in place of the resistance elements 52a and 52b in the semiconductor drive device 10 according to the first embodiment.

The diodes 252a and 252b are connected in a direction in which a charging current can flow from the common positive power supply 6 to the capacitors 3a and 3b.

The diode 252a is inserted in the reference power supply line 51. The diode 252a has a first end, which is an anode connected to the negative electrode of the capacitor 3a, and a second end, which is a cathode connected to the first end of the common positive power supply 6.

The diode 252b is inserted in the reference power supply line 51. The diode 252b has a first end, which is an anode connected to the negative electrode of the capacitor 3b, and a second end, which is a cathode connected to the first end of the common positive power supply 6.

In Reference Example 2 shown in the first embodiment, since the resistance elements 52a, 52b, 62a, 62b are configured to be replaced with the diodes 252a, 252b, 262a, 262b, the resistance for suppressing the shunting in the shunt current wraparound path. There is no element. On the other hand, in the present embodiment, the resistance elements 52a and 52b of the resistance elements 52a, 52b, 62a and 62b are replaced with the diodes 252a and 252b. The shunt current Iss flows through the current path RC that sequentially passes through the diode 252a, the common positive power supply 6, the resistance element 62b, and the capacitor 3b. As a result, a resistance element for suppressing the shunt is always present in the shunt path of the shunt current, so that the shunt current can be suppressed. In the present embodiment, it is desirable to set the resistance value of the current path RC of the shunt current Iss to about 1 to 100Ω by the resistance element 62b. For example, the resistance of the resistance element 62b may be set to 1 to 100Ω.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. The shunt current of the current flowing through the second semiconductor element 1b flows through the current path that sequentially passes through the diode 252b, the common positive power supply 6, the resistance element 62a, and the capacitor 3a. Similar to the above, it is desirable to set the resistance value of this current path to about 1 to 100Ω by the resistance element 62a. For example, the resistance of the resistance element 62a may be set to 1 to 100Ω.

According to this embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the fourth embodiment.
In the semiconductor drive device according to the modification of the fourth embodiment, the capacitor 3a uses the on-resistance of the diodes 252a and 252b in a steady state in which the first semiconductor element 1a and the second semiconductor element 1b are continuously driven. , The combined resistance existing in the charging path of 3b is derived, and the capacitance of the capacitors 3a and 3b is adjusted so that the combined resistance and the capacitance of the capacitors 3a and 3b satisfy the equations (4) and (5). adjust.

As described above, also in this modification, the charging time constants τ1a and τ1b of the capacitors 3a and 3b are larger than the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b, as in the first embodiment. Even when the voltages of the capacitors 3a and 3b decrease, the diversion current can be suppressed without deteriorating the driving conditions of the first semiconductor element 1a and the second semiconductor element 1b. As a result, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

Embodiment 5.
FIG. 11 is a diagram showing the configuration of the semiconductor drive device 10F according to the fifth embodiment.

The semiconductor drive device 10F of the fifth embodiment includes diodes 262a, 262b instead of the resistance elements 62a, 62b in the semiconductor drive device 10 according to the first embodiment.

The diodes 262a and 262b are connected in a direction in which a charging current can flow from the common positive power supply 6 to the capacitors 3a and 3b.

The diode 262a is inserted in the positive power supply line 61. The diode 262a has a first end, which is a cathode connected to the positive electrode of the capacitor 3a, and a second end, which is an anode connected to the second end of the common positive power supply 6.

The diode 262b is inserted in the positive power supply line 61. The diode 262b has a first end, which is a cathode connected to the positive electrode of the capacitor 3b, and a second end, which is an anode connected to the second end of the common positive power supply 6.

In Reference Example 2 shown in the first embodiment, since the resistance elements 52a, 52b, 62a, 62b are replaced with the diodes 252a, 252b, 262a, 262b, the shunt current Iss is used to suppress the shunt in the shunt path. There is no resistance element. On the other hand, in the present embodiment, the resistance elements 62a and 62b of the resistance elements 52a, 52b, 62a and 62b are replaced with the diodes 262a and 262b. The shunt current Iss flows through the current path RC that sequentially passes through the resistance element 52a, the common positive power supply 6, the diode 262b, and the capacitor 3b. As a result, the resistance element for suppressing the shunt is always present in the wraparound path of the shunt current Is, so that the shunt current Is can be suppressed. In the present embodiment, the resistance value of the current path RC of the shunt current Iss is set to about 1 to 100Ω by the resistance element 52a. For example, the resistance of the resistance element 52a may be set to 1 to 100Ω.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. The shunt current of the current flowing through the second semiconductor element 1b flows through a path that passes through the resistance element 52b, the common positive power supply 6, the diode 262a, and the capacitor 3a in this order. Similar to the above, it is desirable to set the resistance value of this current path to about 1 to 100Ω by the resistance element 52b. For example, the resistance of the resistance element 52b may be set to 1 to 100Ω.

According to this embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the fifth embodiment.
The semiconductor drive device according to the fifth modification of the embodiment uses the on-resistance of the diodes 262a and 262b in a steady state in which the semiconductor element is continuously driven to derive the combined resistance existing in the charging path of the capacitors 3a and 3b. Then, the capacitance of the capacitors 3a and 3b is adjusted so that the combined resistance and the capacitance of the capacitors 3a and 3b satisfy the equations (4) and (5).

As a result, even when the charging time constants τ1a and τ1b of the capacitors 3a and 3b are larger than the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b and the voltage of the capacitors 3a and 3b decreases. The diversion current can be suppressed without deteriorating the driving conditions of the first semiconductor element 1a and the second semiconductor element 1b. As a result, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

Embodiment 6.
FIG. 12 is a diagram showing the configuration of the semiconductor drive device 10G according to the sixth embodiment.

The semiconductor drive device 10G of the sixth embodiment includes diodes 262a, 262b instead of the resistance elements 62a, 62b in the semiconductor drive device 10D according to the second embodiment.

The diodes 262a and 262b are connected in a direction in which a charging current can flow from the common positive power supply 6 to the capacitors 3a and 3b.

The diode 262a is inserted in the positive power supply line 61. The diode 262a has a first end, which is a cathode connected to the positive electrode of the capacitor 3a, and a second end, which is an anode connected to the second end of the common positive power supply 6.

The diode 262b is inserted in the positive power supply line 61. The diode 262b has a first end, which is a cathode connected to the positive electrode of the capacitor 3b, and a second end, which is an anode connected to the second end of the common positive power supply 6.

According to the present embodiment, in the semiconductor drive device having the common positive power supply and the common negative power supply, the resistance elements 62a and 62b among the resistance elements 62a, 62b, 72a and 72b are replaced with the diodes 262a and 262b.

The shunt current does not flow in the current path RB described in the second embodiment, but flows in the current paths RA and RD. That is, the shunt current Iss flows through the current path RA that sequentially passes through the resistance element 52a and the resistance element 52b of the reference power supply line. The resistance value of the current path RA of the shunt current Is may be set to about 1 to 100 Ω by the resistance elements 52a and 52b. For example, the combined resistance of the resistance element 52a and the resistance element 52b may be set to 1 to 100Ω. Further, the shunt current Iss3 flows through the current path RD that sequentially passes through the capacitor 4a, the resistance element 72a, the resistance element 72b, and the capacitor 4b. The resistance value of the current path RD of the shunt current Is3 may be set to about 1 to 100Ω by the resistance elements 72a and 72b. For example, the combined resistance of the resistance element 72a and the resistance element 72b may be set to 1 to 100Ω.

In the present embodiment, the diodes 262a and 262b can cut off the current in one direction, and a resistance element for suppressing the shunt is always present in the shunt path of the shunt current, so that the shunt current is suppressed. Can be done.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. A part of the shunt current of the current flowing through the second semiconductor element 1b flows through the resistance element 52b and the resistance element 52a of the reference power supply line in order. The resistance value of the current path of the shunt current may be set to about 1 to 100 Ω by the resistance elements 52a and 52b. For example, the combined resistance of the resistance element 52a and the resistance element 52b may be set to 1 to 100Ω. Another part of the shunt current flows through the current path that sequentially passes through the capacitor 4b, the resistance element 72b, the resistance element 72a, and the capacitor 4a. The resistance value of the current path of this shunt current may be set to about 1 to 100 Ω by the resistance elements 72a and 72b. For example, the combined resistance of the resistance element 72a and the resistance element 72b may be set to 1 to 100Ω.

According to this embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the sixth embodiment.
In the semiconductor drive device according to the modification of the sixth embodiment, the combined resistance existing in the charging path of the capacitors 3a and 3b is used by using the on-resistance of the diodes 262a and 262b in the steady state in which the semiconductor element is continuously driven. It is derived, and the capacitance of the capacitors 3a and 3b is adjusted so that the combined resistance and the capacitance of the capacitors 3a and 3b satisfy the equations (4) and (5).

As a result, even when the charging time constants τ1a and τ1b of the capacitors 3a and 3b are larger than the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b and the voltage of the capacitors 3a and 3b decreases. The diversion current can be suppressed without deteriorating the driving conditions of the first semiconductor element 1a and the second semiconductor element 1b. As a result, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

Embodiment 7.
FIG. 13 is a diagram showing the configuration of the semiconductor drive device 10H according to the seventh embodiment.

The semiconductor drive device 10H of the seventh embodiment includes diodes 272a, 272b instead of the resistance elements 72a, 72b in the semiconductor drive device 10D according to the second embodiment.

The diodes 272a and 272b are connected in a direction in which a charging current can flow from the common negative power supply 7 to the capacitors 4a and 4b.

The diode 272a is inserted in the negative power supply line 71. The diode 272a has a first end, which is an anode connected to the negative electrode of the capacitor 4a, and a second end, which is a cathode connected to the second end of the common negative power source 7.

The diode 272b is inserted in the negative power supply line 71. The diode 272b has a first end, which is an anode connected to the negative electrode of the capacitor 4b, and a second end, which is a cathode connected to the second end of the common negative power source 7.

According to the present embodiment, in the semiconductor drive device having the common positive power supply and the common negative power supply, the resistance elements 72a and 72b among the resistance elements 62a, 62b, 72a and 72b are replaced with the diodes 272a and 272b.

The shunt current does not flow in the current path RD described in the second embodiment, but flows in the current paths RA and RB. That is, the shunt current Iss flows through the current path RA that sequentially passes through the resistance element 52a and the resistance element 52b of the reference power supply line. The resistance value of the current path of the shunt current may be set to about 1 to 100 Ω by the resistance elements 52a and 52b. For example, the combined resistance of the resistance element 52a and the resistance element 52b may be set to 1 to 100Ω.

The shunt current Iss2 flows through the current path RB that sequentially passes through the capacitor 3a, the resistance element 62a, the resistance element 62b, and the capacitor 3b. The resistance value of the current path of the shunt current may be set to about 1 to 100 Ω by the resistance elements 62a and 62b. For example, the combined resistance of the resistance element 62a and the resistance element 62b may be set to 1 to 100Ω.

In the present embodiment, the diodes 272a and 272b can cut off the current in one direction, and a resistance element for suppressing the shunt is always present in the shunt path of the shunt current, so that the shunt current is suppressed. Can be done.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. A part of the shunt current of the current flowing through the second semiconductor element 1b flows through the resistance element 52b and the resistance element 52a of the reference power supply line in order. Another part of the shunt current flows through the path passing through the capacitor 3b, the resistance element 62b, the resistance element 62a, and the capacitor 3a in order.

According to this embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the seventh embodiment.
In the semiconductor drive device according to the modification of the seventh embodiment, the combined resistance existing in the charging path of the capacitors 4a and 4b is used by using the on-resistance of the diodes 272a and 272b in the steady state in which the semiconductor element is continuously driven. It is derived, and the capacitance of the capacitors 4a and 4b is adjusted so that the combined resistance and the capacitance of the capacitors 4a and 4b satisfy the equations (6) and (7).

As a result, even when the charging time constants τ2a and τ2b of the capacitors 4a and 4b are larger than the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b and the voltage of the capacitors 4a and 4b decreases. The diversion current can be suppressed without deteriorating the driving conditions of the first semiconductor element 1a and the second semiconductor element 1b. As a result, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

Embodiment 8.
FIG. 14 is a diagram showing the configuration of the semiconductor drive device 10I according to the eighth embodiment.

The semiconductor drive device 10I of the eighth embodiment includes diodes 252a and 252b in place of the resistance elements 52a and 52b in the semiconductor drive device 10D according to the second embodiment.

The diodes 252a and 252b are connected in a direction in which a charging current can flow from the common positive power supply 6 to the capacitors 3a and 3b. Alternatively, the diodes 252a and 252b may be connected in a direction in which a charging current can flow from the common negative power supply 7 to the capacitors 4a and 4b.

The diode 252a is inserted in the reference power supply line 51. The diode 252a is a cathode connected to the first end of the anode connected to the negative electrode of the capacitor 3a and the positive electrode of the capacitor 4a, the first end of the common positive power supply 6, and the first end of the common negative power supply 7. It has two ends.

The diode 252b is inserted in the reference power supply line 51. The diode 252b is a cathode connected to the first end of the anode connected to the negative electrode of the capacitor 3b and the positive electrode of the capacitor 4b, and the first end of the common positive power supply 6 and the first end of the common negative power supply 7. It has two ends.

According to the present embodiment, in the semiconductor drive device having the common positive power supply and the common negative power supply, the resistance elements 72a and 72b among the resistance elements 62a, 62b, 72a and 72b are replaced with the diodes 272a and 272b.

The shunt current flows through the current path RD described in the second embodiment and the current path RC described in the fourth embodiment. That is, the shunt current Iss flows through the current path RC that sequentially passes through the diode 252a, the common positive power supply 6, the resistance element 62b, and the capacitor 3b. The resistance value of the current path of this shunt current may be set to about 1 to 100 Ω by the resistance element 62b. For example, the resistance of the resistance element 62b may be set to 1 to 100Ω. The shunt current Iss3 flows through the current path RD that sequentially passes through the capacitor 4a, the resistance element 72a, the resistance element 72b, and the capacitor 4b. The resistance value of the current path of this shunt current may be set to about 1 to 100 Ω by the resistance elements 72a and 72b. For example, the combined resistance of the resistance element 72a and the resistance element 72b may be set to 1 to 100Ω.

In the present embodiment, the diodes 252a and 252b can cut off the current in one direction, and a resistance element for suppressing the shunt is always present in the shunt path of the shunt current, so that the shunt current is suppressed. Can be done.

In the above description, the configuration and operation of the first semiconductor element 1a and the first drive unit 100a have been described, but the configuration and operation of the second semiconductor element 1b and the second drive unit 100b are also the same. A part of the shunt current of the current flowing through the second semiconductor element 1b flows through the current path passing through the diode 252b, the common positive power supply 6, the resistance element 62a, and the capacitor 3a in this order. The resistance value of the current path of this shunt current may be set to about 1 to 100 Ω by the resistance element 62a. For example, the resistance of the resistance element 62a may be set to 1 to 100Ω. Another part of the shunt current flows through the current path that sequentially passes through the capacitor 4b, the resistance element 72b, the resistance element 72a, and the capacitor 4a. The resistance value of the current path of this shunt current may be set to about 1 to 100 Ω by the resistance elements 72a and 72b. For example, the combined resistance of the resistance element 72a and the resistance element 72b may be set to 1 to 100Ω.

According to this embodiment, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

A modified example of the eighth embodiment.
In the semiconductor drive device according to the modification of the eighth embodiment, the combined resistance existing in the charging path of the capacitors 3a and 3b is used by using the on-resistance of the diodes 252a and 252b in the steady state in which the semiconductor element is continuously driven. It is derived, and the capacitance of the capacitors 3a and 3b is adjusted so that the combined resistance and the capacitance of the capacitors 3a and 3b satisfy the equations (4) and (5). Further, the combined resistance existing in the charging path of the capacitors 4a and 4b is derived by using the on-resistance of the diodes 252a and 252b, and the combined resistance and the capacitance of the capacitors 4a and 4b are calculated by the equations (6) and (7). The capacitance of the capacitors 4a and 4b is adjusted so as to satisfy the above.

As a result, even when the charging time constants τ2a and τ2b of the capacitors 4a and 4b are larger than the drive cycles Ta and Tb of the first semiconductor element 1a and the second semiconductor element 1b and the voltage of the capacitors 4a and 4b decreases. The diversion current can be suppressed without deteriorating the driving conditions of the first semiconductor element 1a and the second semiconductor element 1b. As a result, it is possible to drive with improved drive reliability by suppressing wiring burnout, malfunction of peripheral circuits, voltage fluctuation, and the like.

In the fourth to eighth embodiments and their modifications, the diode is provided in place of the resistance element, but the diode may be connected in parallel to the resistance element. In this case, until the diode is turned on, the current passes only through the resistance element to charge the capacitor.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.

1a 1st semiconductor element, 1b 2nd semiconductor element, 2a, 2b drive circuit, 3a, 3b, 4a, 4b capacitor, 5 reference potential, 6 common positive power supply, 7 common negative power supply, 10, 10A, 10B, 10C , 10D, 10E, 10F, 10G, 10H, 10I Semiconductor drive device, 51 Reference power supply line, 61 Positive power supply line, 71 Negative power supply line, 52a, 52b, 62a, 62b, 72a, 72b resistor, 100a First drive unit , 100b Second drive unit, 152a, 152b, 162a, 162b, 172a, 172b inductor, 252a, 252b, 262a, 262b, 272a, 272b diode.

Claims (17)

A semiconductor driving device that drives a first semiconductor element and a second semiconductor element.
A first drive unit connected to the negative electrode and the control electrode of the first semiconductor element, and
A second drive unit connected to the negative electrode and the control electrode of the second semiconductor element, and
A common positive power supply including a first end connected to the reference potential and a second end having a positive potential with respect to the reference potential.
The reference power supply line connected to the reference potential side of the common positive power supply,
It is provided with a positive power supply line connected to the positive potential side of the common positive power supply.
Each of the first drive unit and the second drive unit
A drive circuit that controls the potential of the control electrode of the first semiconductor element or the second semiconductor element, and
A first capacitor connected between the positive power supply line and the reference power supply line,
A first element having a first end inserted into the positive power supply line and connected to the positive electrode of the first capacitor, and a second end connected to the second end of the common positive power supply.
A second element interposed in the reference power supply line and having a first end connected to the negative electrode of the first capacitor and a second end connected to the first end of the common positive power supply. Prepare,
The negative electrode of the first semiconductor element and the negative electrode of the second semiconductor element are connected to each other.
The first element and the second element are diodes connected in a direction capable of passing a charging current from the resistance element or the common positive power source to the first capacitor, and the first element and the first element and the second element are connected. At least one of the second elements is a semiconductor drive device which is a resistance element. The semiconductor drive device according to claim 1, wherein both the first element and the second element are resistance elements. One of the first element and the second element is a resistance element.
The semiconductor drive device according to claim 1, wherein the other of the first element and the second element is a diode. Claimed that the magnitude of the combined resistance of the resistance component of the first element of the first drive unit and the resistance component of the first element of the second drive unit is in the range of 1 to 100 Ω. 2. The semiconductor drive device according to 2. Claimed that the magnitude of the combined resistance of the resistance component of the second element of the first drive unit and the resistance component of the second element of the second drive unit is in the range of 1 to 100 Ω. 2. The semiconductor drive device according to 2. The semiconductor drive device according to claim 1, wherein the charging time constant of the first capacitor in the first drive unit is smaller than the drive cycle of the first semiconductor element. The semiconductor drive device according to claim 6, wherein the charging time constant of the first capacitor in the second drive unit is smaller than the drive cycle of the second semiconductor element. The charging time constant of the first capacitor in the first driving unit is larger than the driving period of the first semiconductor element.
When the first semiconductor element is turned on once, the amount of charge for charging the control electrode of the first semiconductor element is Qga [C], and the resistance component of the first element in the first drive unit is The combined resistance of and the resistance component of the second element in the first drive unit is R1a [Ω], the capacitance of the first capacitor in the first drive unit is C1a [F], and the first. When the drive cycle of the semiconductor element of 1 is Ta [s], the following conditions are satisfied.

The semiconductor drive device according to claim 1. The charging time constant of the first capacitor in the second driving unit is larger than the driving period of the second semiconductor element.
When the second semiconductor element is turned on once, the amount of charge for charging the control electrode of the second semiconductor element is Qgb [C], and the resistance component of the first element in the second drive unit is set. The combined resistance of the resistance component of the second element in the second drive unit is R1b [Ω], the capacitance of the first capacitor in the second drive unit is C1b [F], and the first. When the drive period of the semiconductor element of 2 is Tb [s], the following conditions are satisfied.

The semiconductor drive device according to claim 8. A common negative power source including a first end connected to the reference potential and a second end having a negative potential with respect to the reference potential.
Further provided with a negative power supply line connected to the negative potential side of the common negative power supply,
Each of the first drive unit and the second drive unit further
A second capacitor connected between the reference power supply line and the negative power supply line,
A third element interposed in the negative power supply line and having a first end connected to the negative electrode of the second capacitor and a second end connected to the second end of the common negative power supply. Including,
The third element is a resistance element or a diode.
The semiconductor drive device according to claim 1, wherein at least two of the first element, the second element, and the third element are resistance elements. The semiconductor drive device according to claim 10, wherein the first element, the second element, and the third element are resistance elements. The semiconductor drive device according to claim 10, wherein two of the first element, the second element, and the third element are resistance elements, and the remaining one is a diode. A claim that the magnitude of the combined resistance of the resistance component of the third element of the first drive unit and the resistance component of the third element of the second drive unit is in the range of 1 to 100 Ω. 11. The semiconductor drive device according to 11. The semiconductor drive device according to claim 10, wherein the charging time constant of the second capacitor in the first drive unit is smaller than the drive cycle of the first semiconductor element. The semiconductor drive device according to claim 14, wherein the charging time constant of the second capacitor in the second drive unit is smaller than the drive cycle of the second semiconductor element. The charging time constant of the second capacitor in the first driving unit is larger than the driving period of the first semiconductor element.
When the first semiconductor element is turned on once, the amount of charge for charging the control electrode of the first semiconductor element is Qga [C], and the resistance component of the second element in the first drive unit is The combined resistance of the resistance component of the third element in the first drive unit is R2a [Ω], the capacitance of the second capacitor in the first drive unit is C2a [F], and the first. When the drive cycle of the semiconductor element of 1 is Ta [s], the following conditions are satisfied.

The semiconductor drive device according to claim 10. The charging time constant of the second capacitor in the second driving unit is larger than the driving period of the second semiconductor element.
When the second semiconductor element is turned on once, the amount of charge for charging the control electrode of the second semiconductor element is Qgb [C], and the resistance component of the second element in the second drive unit is The combined resistance of the resistance component of the third element in the second drive unit is R2b [Ω], the capacitance of the second capacitor in the second drive unit is C2b [F], and the second. When the drive period of the semiconductor element of 2 is Tb [s], the following conditions are satisfied.

The semiconductor driving device according to claim 16.

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