WO2023032407A1

WO2023032407A1 - Rectifier circuit, and semiconductor device and power supply device using same

Info

Publication number: WO2023032407A1
Application number: PCT/JP2022/023631
Authority: WO
Inventors: 明寛三輪; 浩幸庄司; 順一坂野; 智之内海; 孝裕樋口
Original assignee: 株式会社日立パワーデバイス
Priority date: 2021-08-31
Filing date: 2022-06-13
Publication date: 2023-03-09
Also published as: JP2023034562A

Abstract

Disclosed is a rectifier circuit that makes it possible to achieve a high breakdown voltage while suppressing an increase in power loss, and a semiconductor device and a power supply device using this rectifier circuit. This rectifier circuit supplies a current in one direction, said rectifier circuit comprising: a first enhancement type MOSFET (QH1); a second enhancement type MOSFET (QL1) that is connected in series to the first MOSFET and that has a lower breakdown voltage than the first MOSFET; a control circuit (1) that causes the first MOSFET and the second MOSFET to perform a rectification operation; and a capacitor (C1) that supplies power to the control circuit and that is charged by the voltage between the drain and the source of the second MOSFET.

Description

Rectifier circuit, semiconductor device and power supply device using the same

The present invention relates to a rectifier circuit, and a semiconductor device and a power supply device using the rectifier circuit.

Diode rectifier circuits and synchronous rectifier circuits that use MOSFETs are used as rectifier circuits that are used in power supply devices and convert alternating current into direct current. A synchronous rectifier circuit has low power loss because a MOSFET does not have a built-in potential like a diode and a forward current rises from 0V. Therefore, synchronous rectification circuits are used in power supply devices that require low loss, such as front-end power supplies.

The techniques described in Patent Document 1 and Patent Document 2 are known as conventional technologies related to synchronous rectification circuits.

In the technology described in Patent Document 1, a control circuit and a MOSFET are mounted in one package as a low-loss rectifier circuit used in an alternator. Like a diode, this rectifier circuit operates as a two-terminal semiconductor device having a function of flowing current in one direction (rectifying function).

A rectifier circuit based on the technology described in Patent Document 1 is composed of a control circuit having a comparator and a gate driver, a capacitor for supplying power to the control circuit, and a MOSFET. The control circuit turns the MOSFET on and off by means of the gate driver according to the drain-source voltage of the MOSFET detected by the comparator. The capacitor is charged by the drain-source voltage of the MOSFET when the MOSFET is off.

In the technique described in Patent Document 2, a normally-off enhancement-type low-voltage transistor Q1 and a normally-on depression-type high-voltage transistor Q2 are connected in series between an anode (A) and a cathode (K). A low voltage transistor Q1 is turned on and off by the output of the comparator. The comparator receives the source voltage of Q1 connected to the anode and the source voltage of the depletion type high voltage transistor Q3 connected to the cathode together with Q2. A capacitor serving as a power source for the comparator is connected between the anode and the cathode via a high voltage transistor Q3, and is charged by the voltage between the anode and the cathode when Q1 is turned off.

A rectifier circuit according to the technology described in Patent Document 2 operates as a rectifying element having an anode and a cathode, like a diode.

JP 2015-116053 A Japanese Unexamined Patent Application Publication No. 2011-151788

With the technology of Patent Document 1, if a high-voltage MOSFET is used to increase the voltage resistance of the rectifier circuit, the control circuit and capacitors also need to be increased in voltage. Further, when using a semiconductor switching element to control the input voltage to the comparator and the charging voltage of the capacitor to the voltage level of the comparator and the capacitor, a high withstand voltage semiconductor switching element is required. Therefore, increasing the withstand voltage of the rectifier circuit increases the power loss of the rectifier circuit.

In the technique of Patent Document 2, the low withstand voltage transistor Q1 and the high withstand voltage transistor Q2 are connected in series, thereby increasing the withstand voltage of the rectifier circuit. However, since the high voltage transistor Q3 is used to control the input voltage to the comparator and the charging voltage of the capacitor, power loss in the rectifier circuit increases.

Accordingly, the present invention provides a rectifier circuit capable of increasing the withstand voltage while suppressing an increase in power loss, as well as a semiconductor device and a power supply device using this rectifier circuit.

In order to solve the above-mentioned problems, the rectifier circuit according to the present invention allows a current to flow in one direction, and includes a first enhancement-type MOSFET, and a first MOSFET connected in series to the first MOSFET. an enhancement-type second MOSFET with a low withstand voltage, a control circuit that rectifies both the first MOSFET and the second MOSFET, a power supply to the control circuit, and a drain-source voltage in the second MOSFET and a capacitor charged by

In order to solve the above problems, a semiconductor device according to the present invention includes a rectifier circuit and a semiconductor package containing the rectifier circuit, and the rectifier circuit is the rectifier circuit according to the present invention.

In order to solve the above-described problems, a semiconductor device according to the present invention includes a bridge rectifier circuit including a plurality of rectifier circuits, and a semiconductor package containing the bridge rectifier circuits. Each is a rectifier circuit according to the invention as described above.

In order to solve the above problems, a power supply device according to the present invention has a rectifier circuit section, and the rectifier circuit section includes the rectifier circuit according to the present invention.

According to the present invention, it is possible to increase the withstand voltage of the rectifier circuit while suppressing an increase in power loss. As a result, the power loss of a semiconductor device having a rectifier circuit or a power supply device having a rectifier circuit section can be reduced.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a circuit diagram showing the configuration of a rectifier circuit that is Example 1. FIG. FIG. 10 is a circuit diagram showing the configuration of a rectifier circuit that is Example 2; FIG. 11 is a circuit diagram showing the configuration of a rectifier circuit that is Example 3; FIG. 10 is a current/voltage waveform diagram showing the operation of the rectifier circuit of Example 4; FIG. 11 is a configuration diagram of a semiconductor device that is Example 5; FIG. 11 is a configuration diagram of a semiconductor device that is Example 6; FIG. 11 is a circuit diagram showing the configuration of a power supply device that is Embodiment 7; FIG. 3 is a circuit diagram showing the configuration of a rectifier circuit as a first comparative example; FIG. 5 is a circuit diagram showing the configuration of a rectifier circuit that is a second comparative example;

Hereinafter, embodiments of the present invention will be described with reference to the drawings in Examples 1 to 7 below. In each figure, the same reference numbers denote the same components or components with similar functions.

FIG. 1 is a circuit diagram showing the configuration of a rectifier circuit that is Embodiment 1 of the present invention.

As shown in FIG. 1, the rectifier circuit of the first embodiment includes a MOSFET QH1 with a high withstand voltage (for example, several hundred V or more) connected in series between a first terminal T1 and a second terminal T2, and a MOSFET QH1 It consists of a MOSFET QL1 with a lower withstand voltage, a control circuit 1, a diode D1, and a capacitor C1.

The source of the MOSFET QL1 and the drain of the MOSFET QH1 are connected to the first terminal T1 and the second terminal T2, respectively. The drain of QL1 and the source of QH1 are connected together to form a series connection point. In Example 1, the rectified current (I _S ) flows in the direction from T1 to T2 in the series connection of QH1 and QL1, and does not flow in the direction from T2 to T1.

In addition, in Example 1, MOSFET QL1 and MOSFET QH1 are enhancement-type n-channel MOSFETs.

The control circuit 1 comprises a comparator COMP1 and a gate driver GD1. Comparator COMP1 compares the drain-source voltage V _QL1DS of MOSFET QL1 with a predetermined threshold. The gate driver GD1 generates a control signal for controlling ON/OFF of the MOSFET QL1 and MOSFET QH1 based on the comparison result of the comparator COMP1. That is, MOSFET QL1 and MOSFET QH1 are turned on and off simultaneously by the same gate driver GD1.

Capacitor C1 supplies power to comparator COMP1 and gate driver GD1. When the MOSFET QL1 is off, the positive voltage of the voltage V _QL1DS applied across the drain-source of the MOSFET QL1 causes a flow from the drain terminal of the MOSFET QL1 to the source terminal via the capacitor C1 and the anti-backflow diode D1. The current charges the capacitor C1.

At this time, the drain-source voltage V _QL1DS of the MOSFET QL1 is obtained by changing the voltage applied between the first terminal T1 and the second terminal T2 by the circuit section consisting of the MOSFET QL1, the MOSFET QH1 and the capacitor C1 It is the voltage to be divided. The magnitude of V _QL1DS is mainly determined by the ratio of the drain-source parasitic capacitance of MOSFET QH1, the drain-source parasitic capacitance of MOSFET QL1, and the capacitance of capacitor C1. Therefore, the voltage applied to the capacitor and the The detection voltage (input voltage) of the comparator can be set to a desired voltage level that is lower than the withstand voltage of the series connection of QH1 and QL1 and suitable for the capacitor and comparator.

The synchronous rectification operation of the rectifier circuit in FIG. 1 will be described below.

First, the turn-on operation will be explained.

When the rectified current (I _S ) starts to flow from the first terminal T1 to the second terminal T2, the I _S flows through each body diode (parasitic diode) of the MOSFETs QH1 and QL1. At this time, the drain-source voltage (V _QL1DS ) of MOSFET QL1 becomes a negative value due to the forward voltage of the body diode. When the value of V _QL1DS becomes less than the threshold (V _TH1 ) of comparator COMP1, the output of comparator COMP1 transitions from low to high. When the output of the comparator COMP1 becomes high level, the gate driver GD1 outputs an on-gate signal to each gate of the MOSFETs QH1 and QL1. This increases the gate-source voltage of MOSFET QH1 (V _QH1GS ) and the gate-source voltage of MOSFET QL1 (V _QL1GS ), thus turning on MOSFETs QH1 and QL1.

After MOSFETs QH1 and QL1 turn on, a rectified current (I _S ) flows through each channel of MOSFETs QH1 and QL1. At this time, the drain-source voltage (V _QL1DS ) of the MOSFET QL1 is expressed by the product of the ON resistance of the MOSFET QL1 and I _S . For the same _IS , the voltage drop across the on-resistance of the MOSFET is smaller than the on-voltage of the body diode, resulting in a low loss rectifier circuit.

Next, the turn-off operation will be explained.

As the rectified current (I _S ) decreases, the drain-source voltage (V _QL1DS (negative value)) of MOSFET QL1 increases. When the value of V _QL1DS becomes greater than the threshold (V _TH1 ) of comparator COMP1, the output of comparator COMP1 transitions from high to low. When the output of comparator COMP1 goes low, gate driver GD1 outputs an off-gate signal to each gate of MOSFETs QH1 and QL1. This causes the gate-source voltage of MOSFET QH1 (V _QH1GS ) and the gate-source voltage of MOSFET QL1 (V _QL1GS ) to decrease, thus turning off MOSFETs QH1 and QL1.

After MOSFETs QH1 and QL1 turn off, the drain-to-source voltage of MOSFET QL1 (V _QL1DS (positive value)) divided by the circuit portion consisting of the respective drain-to-source capacitances of MOSFETs QH1 and QL1 and capacitor C1 , C1 are charged again.

When the MOSFETs QH1 and QL1 are off, the gate-source voltage V _QH1GS of the MOSFET QH1 is equal to the output voltage of the gate driver (=0) minus the drain-source voltage V _QL1DS of the MOSFET QL1. Therefore, V _QL1DS in the off state is preferably set lower than the breakdown voltage between the gate and source of MOSFET QH1. Alternatively, the gate-source breakdown voltage of MOSFET QH1 is preferably higher than V _QL1DS in the off state.

Here, a comparative example of Example 1 will be described. Synchronous rectification by turning on/off the MOSFET is applied in each of the comparative examples.

FIG. 8 is a circuit diagram showing the configuration of a rectifier circuit as a first comparative example.

In the first comparative example, one MOSFET is used in the same manner as the technique of Patent Document 1 described above. In FIG. 8, the high-voltage MOSFET QH1 is turned on and off, and the rectified current flows through the high-voltage MOSFET QH1. Furthermore, as shown in FIG. 8, the detection voltage of the capacitor C1 is controlled to a desired level by the high voltage MOSFET QH2, and the detection voltage input to the comparator COMP1 is controlled to a desired level by the high voltage MOSFET QH3. controlled. Note that the detection voltage input to the comparator COMP1 is suppressed below the differential input voltage of the comparator COMP1.

In addition, in the first comparative example, a capacitor C2 is connected in series with the high voltage MOSFET QH2, and this capacitor C2 is connected to the input of the comparator COMP1. A series circuit of a Zener diode ZD1 and a resistor R3 is connected between the first terminal T1 and the second terminal T2 in order to generate a gate drive voltage for the high voltage MOSFET QH3. Thus, the number of parts increases in the first comparative example.

FIG. 9 is a circuit diagram showing the configuration of a rectifier circuit that is a second comparative example.

In the second comparative example, an enhancement-type low-voltage MOSFET QL1 and a depletion-type high-voltage MOSFET QH1 are connected in series, and a rectified current flows through the low-voltage MOSFET QL1 and the high-voltage MOSFET QH1. The low voltage MOSFET QL1 is turned on/off, and the high voltage MOSFET QH1 increases the voltage of the rectifier circuit. Further, as shown in FIG. 9, the voltage of the capacitor C1 and the detection voltage of the comparator COMP1 are controlled to desired levels by the depletion type high voltage MOSFET QH2. In this comparative example, QH1 and QH2 operate as normally-on switching elements.

The number of high voltage MOSFETs used in the first comparative example (FIG. 8) and the second comparative example (FIG. 9) is three (QH1, QH2, QH3) and two (QH1, QH2), respectively. In contrast, the number of high voltage MOSFETs used in the first embodiment (FIG. 1) is one. Thus, according to the first embodiment, the power loss of the rectifier circuit can be reduced, and the size and cost of the rectifier circuit can be reduced.

In addition, in the second comparative example (FIG. 9), the high voltage MOSFET QH1, through which a rectified current flows and increases the voltage resistance of the rectifier circuit, is a depletion type MOSFET that operates normally. On the other hand, in Example 1 (FIG. 1), the high voltage MOSFET QH1 is an enhancement type MOSFET. Thus, according to the first embodiment, power loss can be reduced and costs can be reduced.

As described above, according to the first embodiment, the enhancement-type high-voltage MOSFET and the enhancement-type low-voltage MOSFET are connected in series, and the high-voltage MOSFET increases the voltage resistance of the rectifier circuit. Both of the withstand voltage MOSFETs are on/off controlled for rectifying operation. Furthermore, the capacitor, which is the power supply for the control circuit that rectifies the high-voltage MOSFET and the low-voltage MOSFET, is charged by the drain-source voltage of the low-voltage MOSFET, and the control circuit reduces the drain-source voltage of the low-voltage MOSFET. The voltage is detected, and the high-voltage MOSFET and the low-voltage MOSFET are rectified according to the detected voltage.

As a result, the power supply for the control circuit and the voltage level of the detection voltage can be set to a desired level without using a control element such as a high-voltage MOSFET while increasing the withstand voltage of the rectifier circuit. Furthermore, since the high voltage MOSFET through which the rectified current flows is an enhancement type, it is possible to reduce the power loss and the cost. Therefore, according to the first embodiment, the withstand voltage of the rectifier circuit can be increased without increasing the power loss and cost.

FIG. 2 is a circuit diagram showing the configuration of a rectifier circuit that is Embodiment 2 of the present invention. Differences from the first embodiment are mainly described below.

As shown in FIG. 2, in Example 2, a Zener diode ZD1 is inserted between the drain and gate of the low-voltage MOSFET QL1. The anode and cathode of Zener diode ZD1 are connected to the gate and drain, respectively. The zener voltage of the zener diode ZD1 should be lower than the withstand voltage of the MOSFET QL1, lower than the rated voltage of the control circuit 1, or lower than the differential input voltage of the comparator COMP1.

When the drain-to-source voltage V _QL1DS of MOSFET QL1 rises above the Zener voltage of Zener diode ZD1, ZD1 breaks down and V _QL1DS is clamped to the desired value set by the Zener voltage.

As a result, the drain-source voltage V _QL1DS of the MOSFET QL1 can be reliably suppressed below the withstand voltage of the MOSFET QL1, or the voltage of the capacitor C1 can be suppressed below the rated voltage of the control circuit 1, or the voltage of the comparator COMP1 The detection voltage can be suppressed below the differential input voltage of COMP1. Also, the magnitude of the voltage between the gate and source of the MOSFET QH1 can be suppressed lower than the withstand voltage between the gate and source of the MOSFET QH1. Therefore, the operational reliability of the rectifier circuit is improved.

FIG. 3 is a circuit diagram showing the configuration of a rectifier circuit that is Embodiment 3 of the present invention. Differences from the first embodiment are mainly described below.

As shown in FIG. 3, in Example 3, resistors R2 and R1 are connected in parallel to MOSFETs QL1 and QH1, respectively.

Depending on the ratio of resistors R1 and R2, the voltage applied between the first terminal T1 and the second terminal T2 will be the drain-source voltage V _QH1DS of MOSFET QH1 and the drain-source voltage of MOSFET QL1. V-- _QL1DS and V--QL1DS. Thereby, the value of _VQL1DS can be reliably set to a desired voltage value.

Therefore, according to the third embodiment, the voltage applied to the capacitor and the detected voltage (input voltage) of the comparator can be reliably set to desired voltage levels suitable for the capacitor and comparator.

FIG. 4 is a current/voltage waveform diagram showing the operation of the rectifier circuit that is Example 4 of the present invention. Differences from the first embodiment are mainly described below.

FIG. 4 shows the rectified current Is, the drain-source voltage V _QL1DS of the MOSFET QL1, the gate-source voltage V _QL1GS of the MOSFET QL1, and the gate-source voltage V _QH1GS of the MOSFET QH1. In addition, in FIG. 4, the rectified current _IS is a sine half-wave current.

In Example 4, the circuit configuration is similar to Example 1 (FIG. 1), but unlike Example 1, comparator COMP1 has two threshold values (V _TH1 , V _TH2 ) with different magnitudes.

As shown in FIG. 4, the comparator COMP1 in Example 4 has a first threshold V _TH1 and a second threshold V _TH2 . Both V _TH1 and V _TH2 have negative values. V _TH1 <V _TH2 and the absolute value of V _TH1 is greater than the absolute value of V _TH2 .

The operation of the rectifier circuit of Example 4 will be described below, but the magnitude and increase/decrease of the voltage will be described in consideration of the positive/negative of the voltage.

The comparator COMP1 compares the drain-source voltage V _QL1DS of the MOSFET QL1 with the first threshold value V _TH1 when the MOSFETs QL1 and QH1 are turned on, and compares the drain-source voltage V QL1DS of the MOSFET QL1 with the first threshold value V TH1 when the MOSFETs QL1 and QH1 are turned off. A source-to-source voltage V _QL1DS is compared with a second threshold V _TH2 .

Comparator COMP1 transitions its output from low to high when I _S begins to flow and V _QL1DS changes from positive to negative and then V _QL1DS becomes lower than V _TH1 . As a result, the gate driver GD1 outputs an on-gate signal, increasing V-- _QH1GS and V-- _QL1GS . Therefore, QH1 and QL1 are turned on.

When QH1 and QL1 are turned on, _VQL1DS once increases and then changes in a half-sinusoidal fashion, but does not reach the second threshold _VTH2 . Therefore, the output of the comparator COMP1 is maintained at a high level, so QH1 and QL1 are maintained on.

As I _S decreases and V _QL1DS (<0) increases above V _TH2 (<0), comparator COMP1 transitions its output from high to low. As a result, the gate driver GD1 outputs an off-gate signal, so that V-- _QH1GS and V-- _QL1GS decrease. Therefore, QH1 and QL1 are turned off.

As described above, the threshold with which the comparator COMP1 compares the drain-source voltage V _QL1DS of the MOSFET QL1 differs between the turn-on operation and the turn-off operation, so that the output level of the comparator COMP1 switches between high and low in a short period of time. , so-called chattering can be prevented. This prevents an unstable operation in which the turn-on operation and turn-off operation of the rectifier circuit are repeated in a short period of time.

As described above, according to the fourth embodiment, the operational stability of the rectifier circuit is improved. In particular, when the drain-source voltage V _QL1DS of the MOSFET QL1 after turn-on fluctuates greatly, setting V _TH1 and V _TH2 according to the fluctuation range of V _QL1DS improves the stability of the operation of the rectifier circuit. definitely improve.

A hysteresis comparator, for example, can be applied as the comparator in the fourth embodiment.

FIG. 5 is a configuration diagram of a semiconductor device that is Embodiment 5 of the present invention.

As shown in FIG. 5, in Example 5, a rectifier circuit 2 is built in a semiconductor package 3 as a semiconductor circuit. As the rectifier circuit 2, the rectifier circuit of Example 1 (FIG. 1) is applied. Therefore, the high-voltage MOSFET Q1, the low-voltage MOSFET Q2, the capacitor C1, the backflow prevention diode D1, and the control circuit 1 (comparator COMP1, gate driver GD1), which constitute the rectifier circuit 2, are incorporated in the semiconductor package 3.

In the semiconductor package 3, the rectifier circuit 2 is resin-sealed with molding resin or a resin case, and the first terminal T1 and the second terminal T2 are exposed on the outer surface of the resin that seals the rectifier circuit 2. there is

According to the fifth embodiment, the synchronous rectification circuit can be easily applied as a substitute for the rectifier diode, and the electrical/electronic device provided with the rectifier circuit section can be reduced in loss.

Although the semiconductor device of Example 5 uses synchronous rectification, it operates as a two-terminal rectifying element like a diode. Therefore, it is possible to reduce man-hours for designing and mounting the electric/electronic device including the rectifier circuit section.

As the rectifier circuit 2, any one of the rectifier circuits of Examples 2 to 4 may be applied.

FIG. 6 is a configuration diagram of a semiconductor device that is Embodiment 6 of the present invention.

As shown in FIG. 6, in the sixth embodiment,

rectifier circuits

2, 5, 6, and 7 are incorporated in a semiconductor package 4 as semiconductor circuits. A circuit similar to that of the first embodiment (FIG. 1) is applied to the rectifier circuit 2 . A circuit similar to that of the first embodiment (FIG. 1) is applied to each of the rectifier circuits 5, 6, and 7 as well. These

rectifier circuits

2, 5, 6 and 7 form a single-phase bridge rectifier circuit.

In the semiconductor package 4, the

rectifier circuits

2, 5, 6, and 7 are resin-sealed with molding resin or a resin case, and a pair of AC terminals T4, T5 and a pair of DC terminals T3, T6 of the single-phase bridge rectifier circuit are connected. , are exposed to the outer surface of the resin that seals the

rectifier circuits

2, 5, 6, 7.

According to the sixth embodiment, the synchronous rectifier circuit can be easily applied to the single-phase bridge rectifier circuit as a substitute for the rectifier diode, and the loss of the single-phase bridge rectifier circuit and the electric/electronic device equipped with the single-phase bridge rectifier circuit can be reduced. can do.

The semiconductor device of Example 6 can have compatibility with the diode bridge by matching the arrangement of the AC terminals T4, T5 and the DC terminals T3, T6 in the semiconductor package 4 with the packaged diode bridge. . In addition, the semiconductor device of Example 6 operates as a four-terminal rectifying element like a single-phase diode bridge while using synchronous rectification. Therefore, it is possible to reduce man-hours for designing and mounting an electric/electronic device including a full-wave rectifier circuit.

As the

rectifier circuits

2, 5, 6, and 7, any one of the rectifier circuits of Examples 2 to 4 may be applied. A three-phase bridge rectifier circuit can be configured by using six rectifier circuits of any one of Examples 1 to 4. In this case, three AC terminals and a pair of DC terminals for three phases are exposed on the outer surface of the resin that seals the six rectifier circuits.

FIG. 7 is a circuit diagram showing the configuration of a power supply device that is Embodiment 7 of the present invention.

The power supply device in FIG. 7 converts AC power from a commercial AC power supply into DC power with a desired voltage and outputs the DC power.

In FIG. 7, among the rectifying elements indicated by the circuit symbols of diodes, rectifying elements CRD1 to CRD4 constituting a bridge rectifying circuit for rectifying the AC voltage of the commercial AC voltage, a rectifying element FWD1 for freewheeling in the chopper circuit section, At least one of the rectifying elements SSD1 and SSD2 constituting the rectifying circuit section that receives the AC output power of the inverter circuit section via a transformer and converts it to a desired DC voltage, and the rectifying element ORD1 for preventing backflow. , the rectifier circuit of any one of Examples 1 to 4, or the semiconductor device of Example 5 is applied. The single-phase bridge rectifier circuit of Example 6 may be used for the rectifying elements CRD1 to CRD4.

In addition, in FIG. 7, the rectifying element connected in parallel with the MOSFET is a parasitic diode (body diode) of the MOSFET. Moreover, when all the rectifying elements in FIG. 7 are diodes, the circuit configuration of the power supply device in FIG. 7 is a known circuit configuration.

According to the seventh embodiment, it is possible to reduce the power loss of the power supply device. It should be noted that the power supply device according to the seventh embodiment is suitable for a front-end power supply that requires high efficiency.

The rectifier circuits of Examples 1 to 4 and the semiconductor devices of Examples 5 and 6 can be applied not only to the front power supply but also to various power supply apparatuses having a rectifier circuit section.

It should be noted that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above embodiments have been described in detail to facilitate understanding of the present invention, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

For example, the MOSFET is not limited to an n-channel type, and may be a p-channel type. Moreover, the semiconductor material forming the MOSFET is not limited to silicon (Si), but may be a wide bandgap semiconductor such as silicon carbide (SiC).

1... control circuit, 2, 5, 6, 7... rectifier circuit, 3, 4... semiconductor package

Claims

In a rectifier circuit that allows current to flow in one direction,
an enhancement-type first MOSFET;
a second enhancement-type MOSFET connected in series to the first MOSFET and having a lower breakdown voltage than the first MOSFET;
a control circuit that rectifies both the first MOSFET and the second MOSFET;
a capacitor that supplies power to the control circuit and is charged by the drain-to-source voltage on the second MOSFET;
A rectifier circuit, comprising:
In the rectifier circuit according to claim 1,
The control circuit is
By turning on/off both the first MOSFET and the second MOSFET based on the drain-source voltage in the second MOSFET, both the first MOSFET and the second MOSFET are turned on and off. A rectifier circuit characterized by performing a rectifying operation.
In the rectifier circuit according to claim 1,
The control circuit is
a comparator that switches an output level according to the drain-source voltage in the second MOSFET;
a gate driver that outputs a common gate signal to each gate of the first MOSFET and the second MOSFET according to the output level of the comparator;
A rectifier circuit, comprising:
In the rectifier circuit according to claim 3,
A rectifier circuit, wherein the drain and source of said second MOSFET are connected to the input of said comparator.
In the rectifier circuit according to claim 4,
A rectifier circuit, wherein the drain-source voltage in the second MOSFET is equal to or less than the differential input voltage of the comparator.
2. The rectifier circuit according to claim 1, wherein the withstand voltage between the gate and source of said first MOSFET is higher than the voltage between said drain and source of said second MOSFET when said second MOSFET is off. A rectifier circuit characterized by:
The rectifier circuit according to claim 1, wherein a Zener diode is connected between the drain and gate of said second MOSFET.
The rectifier circuit of claim 1, further comprising:
a first resistor connected in parallel with the first MOSFET;
a second resistor connected in parallel with the second MOSFET;
A rectifier circuit comprising:
In the rectifier circuit according to claim 3,
The rectifier circuit, wherein the comparator compares a first threshold value and a second threshold value having different values with the drain-source voltage of the second MOSFET.
a rectifier circuit;
a semiconductor package containing the rectifier circuit;
In a semiconductor device comprising
A semiconductor device, wherein the rectifier circuit is the rectifier circuit according to any one of claims 1 to 9.
a bridge rectifier circuit composed of a plurality of rectifier circuits;
a semiconductor package containing the bridge rectifier circuit;
In a semiconductor device comprising
10. A semiconductor device, wherein each of the plurality of rectifier circuits is the rectifier circuit according to claim 1.
In a power supply device having a rectifier circuit,
A power supply device, wherein the rectifier circuit section includes the rectifier circuit according to any one of claims 1 to 9.