CN210405259U

CN210405259U - One-way conduction device and switching power supply using same

Info

Publication number: CN210405259U
Application number: CN201921669031.0U
Authority: CN
Inventors: 高红波; 黄必亮; 周逊伟
Original assignee: Joulwatt Technology Hangzhou Co Ltd
Current assignee: Joulwatt Technology Co Ltd
Priority date: 2019-10-08
Filing date: 2019-10-08
Publication date: 2020-04-24
Anticipated expiration: 2029-10-08

Abstract

The utility model provides a one-way conduction device and a switching power supply using the same, which comprises two switching tubes, wherein the body diodes of the two switching tubes are reversely connected in series, and the two switching tubes share a grid and a common source; the drain electrode of one of the switching tubes is connected with the grid electrodes of the two switching tubes. In the application occasion needing unidirectional conduction, the influence caused by the parasitic effect of the diode is avoided.

Description

One-way conduction device and switching power supply using same

Technical Field

The utility model relates to a power electronics field, in particular to one-way switching on device and use its switching power supply.

Background

Fig. 1 illustrates a conventional switching power supply using a diode, in which when a synchronous rectifier M2 is turned on, a supply voltage VDD charges a bootstrap capacitor C0 through a bootstrap diode D0; when the main power tube M1 is turned on, the voltage at the second terminal SW of the M1 tube is suddenly pulled high, and the voltage at the cathode of the diode D0 is pulled high at the same time, which easily causes the chip device to be damaged due to the parasitic capacitance of the diode D0.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a need not use one-way conduction device of diode and use its switching power supply for solve the influence that the applied diode that prior art exists and bring the parasitic effect.

In order to achieve the above object, the utility model provides an one-way conduction device, its characterized in that: the circuit comprises two switching tubes, wherein body diodes of the two switching tubes are reversely connected in series, and the two switching tubes share a grid electrode and a common source; the drain electrode of one of the switching tubes is connected with the grid electrodes of the two switching tubes, the switching tube is used as a first switching tube, and the other switching tube is used as a second switching tube.

Optionally, the two switch tubes are PMOS tubes, the drain of the first switch tube is the anode of the unidirectional conducting device, and the drain of the second switch tube is the cathode of the unidirectional conducting device.

Optionally, the two switch tubes are NMOS tubes, the drain of the first switch tube is the negative electrode of the unidirectional conducting device, and the drain of the second switch tube is the positive electrode of the unidirectional conducting device.

Optionally, the second switching tube includes a resistor, and the body diode of the second switching tube is connected in series with the resistor.

Optionally, the first switching tube includes a resistor, and the body diode of the first switching tube is connected in series with the resistor.

The utility model also provides a switching power supply, including above an arbitrary one-way device that switches on, the supply voltage passes through the one-way drive circuit power supply that switches on the device and give switching power supply.

Compared with the prior art, the utility model has the advantages of it is following: the utility model comprises two switching tubes, the body diodes of the two switching tubes are connected in series in a reverse direction, and the two switching tubes share a grid and a common source; the drain electrode of one of the switching tubes is connected with the grid electrodes of the two switching tubes. In the application occasion needing unidirectional conduction, the influence caused by the parasitic effect of the diode is avoided.

Drawings

FIG. 1 is a schematic diagram of a prior art switching power supply employing diodes;

FIG. 2 is a schematic diagram of an embodiment of the unidirectional flux device of the present invention;

FIG. 3 is a schematic diagram of a second embodiment of the unidirectional flux device of the present invention;

FIG. 4 is a schematic diagram of the unidirectional flux device according to the embodiment of the present invention;

FIG. 5 is a schematic diagram of the fourth embodiment of the unidirectional flux device of the present invention;

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to only these embodiments. The present invention covers any alternatives, modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

In the following description of the preferred embodiments of the present invention, specific details are set forth in order to provide a thorough understanding of the present invention, and it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are simplified and in non-precise proportion, so as to facilitate and clearly assist in explaining the embodiments of the present invention.

As shown in fig. 2, a schematic diagram of an embodiment of the unidirectional conducting device of the present invention is illustrated, which includes two NMOS transistors, the body diodes of the two NMOS transistors are connected in parallel in reverse direction, share a gate and a common source, the gates of the two NMOS transistors are connected to the drain of one of the NMOS transistors, i.e. the a end in the diagram, and correspond to the positive electrode of the unidirectional conducting device; the drain electrode of the other NMOS tube is the end B and corresponds to the negative electrode of the unidirectional conducting device.

As shown in fig. 3, a schematic diagram of a second embodiment of the unidirectional conducting device of the present invention is illustrated, which includes two PMOS transistors, the body diodes of the two PMOS transistors are connected in parallel in reverse direction, share a gate and have a common source, and the gates of the two NMOS transistors are connected to the drain of one of the PMOS transistors, i.e. the B terminal in the diagram, corresponding to the negative electrode of the unidirectional conducting device; the drain electrode of the other NMOS tube is an A end and corresponds to the anode of the one-way conduction device.

Fig. 4 and 5 respectively illustrate a third embodiment and a fourth embodiment of the unidirectional flux device of the present invention, and the difference between the third embodiment and the first embodiment is as follows: the MOS tube corresponding to the cathode of the unidirectional conducting device comprises a resistor which is connected with the body diode in series so as to reduce the leakage current flowing through the body diode when the voltage at the B end is suddenly reduced. The difference between the fourth embodiment and the second embodiment is that: the MOS tube corresponding to the anode of the unidirectional conducting device comprises a resistor which is connected with the body diode in series so as to reduce the leakage current flowing through the body diode when the voltage at the B end is suddenly reduced.

Although the embodiments have been described and illustrated separately, it will be apparent to those skilled in the art that some common techniques may be substituted and integrated between the embodiments, and reference may be made to one of the embodiments not explicitly described, or to another embodiment described.

The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.

Claims

1. A unidirectional flux device, characterized by: the circuit comprises two switching tubes, wherein body diodes of the two switching tubes are reversely connected in series, and the two switching tubes share a grid electrode and a common source; the drain electrode of one of the switching tubes is connected with the grid electrodes of the two switching tubes, the switching tube is used as a first switching tube, and the other switching tube is used as a second switching tube.

2. A unidirectional flux arrangement as claimed in claim 1, wherein: the two switch tubes are PMOS tubes, the drain electrode of the first switch tube is the anode of the one-way conduction device, and the drain electrode of the second switch tube is the cathode of the one-way conduction device.

3. A unidirectional flux arrangement as claimed in claim 1, wherein: the two switch tubes are NMOS tubes, the drain electrode of the first switch tube is the negative electrode of the unidirectional conduction device, and the drain electrode of the second switch tube is the positive electrode of the unidirectional conduction device.

4. A unidirectional flux arrangement as claimed in claim 2, wherein: the second switch tube comprises a resistor, and the body diode of the second switch tube is connected with the resistor in series.

5. A unidirectional flux arrangement as claimed in claim 3, wherein: the first switch tube comprises a resistor, and the body diode of the first switch tube is connected with the resistor in series.

6. A switching power supply, characterized by: comprising a unidirectional conducting device according to any of claims 1-5, through which a supply voltage is supplied to a driving circuit of the switching power supply.