CN219247704U

CN219247704U - DCDC circuit system with input reverse connection protection

Info

Publication number: CN219247704U
Application number: CN202223509986.4U
Authority: CN
Inventors: 张宏远; 吕一航; 文熙凯; 陈利
Original assignee: Shenzhen Hopewind Electric Co Ltd
Current assignee: Shenzhen Hopewind Electric Co Ltd
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2023-06-23
Anticipated expiration: 2032-12-26

Abstract

The application discloses a DCDC circuit system with input reverse connection protection, which comprises an input power supply, a DCDC conversion circuit and a load which are sequentially connected; the input power supply is provided with a first output end and a second output end which are connected with the DCDC conversion circuit, and when the input power supply works normally, the voltage of the first output end is higher than that of the second output end; the DCDC conversion circuit is provided with a first power tube; the DCDC circuit system further comprises a reverse connection protection unit, wherein the reverse connection protection unit comprises a first electric connection end and a second electric connection end, the first electric connection end is connected with the first output end, and the second electric connection end is connected with the second output end; the reverse connection protection unit is in an off state when the input power supply works normally, and is in an on state when the input power supply is in reverse connection. The reverse connection protection unit is in a disconnection state when an input power supply works normally, does not flow current to generate redundant loss, and is in a conduction state when the input power supply is in reverse connection, so that a power tube in a post-stage DCDC conversion circuit is protected.

Description

DCDC circuit system with input reverse connection protection

Technical Field

The application relates to the technical field of electronics, in particular to a DCDC circuit system with input reverse connection protection.

Background

The power tube device is widely applied to a DCDC conversion circuit. Referring to a schematic diagram of DCDC circuitry shown in fig. 1, the circuitry includes an input power source, a DCDC conversion circuit, and a load, the DCDC conversion circuit including power transistors, such as IGBTs, MOS transistors, and the like. When the input power supply is reversely connected, the input power supply is short-circuited due to the existence of a body diode of a power tube in the DCDC conversion circuit, and the short-circuit current is generally larger than the current in normal operation. If the body diode capability of the power tube is insufficient, the power tube may be overheated and damaged, thereby causing the whole circuit system to be failed.

In order to avoid the problem caused by the reverse connection of the input power source, as shown in fig. 2, a diode D1 is connected in series between the a output end of the input power source and the DCDC conversion circuit, and a diode D2 is connected in series between the B output end of the input power source and the DCDC conversion circuit, and one of the diode D1 and the diode D2 may be used at random or simultaneously. When the input power supply is reversely connected, the DCDC conversion circuit is equivalent to open circuit, and no current flows, so that the input reverse connection protection is realized. However, the disadvantage of this reverse connection protection scheme is that, when operating normally, the diode will flow through the operating current, which will cause losses to the whole system.

Disclosure of Invention

The application provides a DCDC circuit system with input reverse connection protection, which aims to solve the problem that the conventional input reverse connection protection scheme can generate redundant loss during normal operation.

The application provides a DCDC circuit system with input reverse connection protection, which comprises an input power supply, a DCDC conversion circuit and a load which are sequentially connected; the input power supply is provided with a first output end and a second output end which are connected with the DCDC conversion circuit, and when the input power supply works normally, the voltage of the first output end is higher than that of the second output end; the DCDC conversion circuit is provided with a first power tube; the DCDC circuit system further comprises a reverse connection protection unit, wherein the reverse connection protection unit comprises a first electric connection end and a second electric connection end, the first electric connection end is connected with the first output end, and the second electric connection end is connected with the second output end; the reverse connection protection unit is configured to be in an off state when the input power supply works normally and in an on state when the input power supply is in reverse connection.

In an example, the first power tube includes an IGBT tube or a MOS tube.

In an example, the reverse connection protection unit includes a diode, a cathode of the diode is connected to the first output terminal, and an anode of the diode is connected to the second output terminal.

In an example, the reverse connection protection unit includes a second power tube, a first electrical connection end of the second power tube is connected with the first output end, a second electrical connection end of the second power tube is connected with the second output end, and a control end of the second power tube receives a first control signal to be turned on or turned off under the action of the control signal.

In an example, the second power tube includes an IGBT tube or a MOS tube.

In an example, the reverse connection protection unit includes a relay, a first electrical connection end of the relay is connected with the first output end, a second electrical connection end of the relay is connected with the second output end, and a control end of the relay receives a second control signal to be attracted or disconnected under the action of the control signal.

According to the DCDC circuit system with the input reverse connection protection, the reverse connection protection unit is in a disconnection state when an input power supply works normally, excessive loss caused by current cannot flow, and the reverse connection protection unit is in a conduction state when the input power supply is in reverse connection, so that a power tube in a post-stage DCDC conversion circuit is protected.

Drawings

FIG. 1 is a schematic diagram of a prior art DCDC circuit system;

FIG. 2 is a schematic diagram of a prior art DCDC circuit system with reverse input protection;

FIG. 3 is a schematic diagram of a DCDC circuit system with reverse input protection according to an embodiment of the present application;

fig. 4 is a schematic diagram of a first reverse connection protection unit according to an embodiment of the present application;

fig. 5 is a schematic diagram of a second reverse connection protection unit according to an embodiment of the present application;

fig. 6 is a schematic diagram of a third reverse connection protection unit according to an embodiment of the present application;

fig. 7 is a schematic diagram of a fourth reverse connection protection unit according to an embodiment of the present application.

The realization, functional characteristics and advantages of the present application will be further described with reference to the embodiments, referring to the attached drawings.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved by the application clearer and more obvious, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

In the description of the present application, it should be understood that the directions or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

As shown in fig. 3-4, a first embodiment of the present application provides a DCDC circuit system with input reverse connection protection, where the DCDC circuit system includes an input power source, a reverse connection protection unit, a DCDC conversion circuit, and a load, where the DCDC conversion circuit includes a power tube, such as an IGBT tube, a MOS tube, and so on.

In this embodiment, one electrical connection end of the reverse connection protection unit is connected to the a output end of the input power supply, and the other electrical connection end of the reverse connection protection unit is connected to the B output end of the input power supply. Specifically, the reverse connection protection unit comprises a diode, the cathode of the diode is connected with the A output end of the input power supply, and the anode of the diode is connected with the B output end of the input power supply.

When the input power supply works normally, the voltage of the output end of the input power supply A is higher than that of the output end of the input power supply B; at this time, the diode is operated in an off state (i.e., an off state), and the reverse connection protection unit corresponds to an off state, and no loss occurs.

When the input power supply is reversely connected, the voltage of the output end of the input power supply A is lower than the voltage of the output end of the input power supply B; at this time, the diode is operated in a conductive state, and most of the current flowing from the input power source flows to the input power source through the reverse connection protection unit, thereby protecting the power tube in the back-end DCDC conversion circuit.

Example two

As shown in fig. 5-6, a DCDC circuit system with reverse input protection is provided in the second example of the present application, which is different from the first embodiment:

the reverse connection protection unit comprises a power tube, such as a MOS tube or an IGBT tube, wherein a first electric connection end of the power tube is connected with an A output end of an input power supply, a second electric connection end of the power tube is connected with a B output end of the input power supply, and a control end of the power tube receives a control signal. Taking an N-channel MOS tube as an example, the drain electrode of the MOS tube is connected with the A output end of the input power supply, and the source electrode of the MOS tube is connected with the B output end of the input power supply. Taking an IGBT tube as an example, a collector of the IGBT tube is connected with an A output end of an input power supply, and an emitter of the IGBT tube is connected with a B output end of the input power supply.

When the input power supply works normally, the power tube is controlled to be in a cut-off state (namely a cut-off state) through the control signal, so that the reverse connection protection unit does not generate loss when the whole system works normally.

When the input power supply is reversely connected, the power tube is controlled to be in a conducting state through the control signal, so that the power tube in the back-end DCDC conversion circuit is protected. Alternatively, using a power tube with a low on-drop body diode, most of the current flowing from the input power source flows through the body diode to the input power source, thereby protecting the power tube in the back-end DCDC conversion circuit.

Example III

As shown in fig. 7, a DCDC circuit system with reverse input protection according to a third embodiment of the present application is different from the first embodiment in that:

the reverse connection protection unit comprises a relay or a device which is similar to the relay and controls on-off characteristics. In this embodiment, a relay is taken as an example, one electrical connection terminal of the relay is connected to an a output terminal of the input power supply, the other electrical connection terminal is connected to a B output terminal of the input power supply, and a control terminal of the relay receives a control signal.

When the input power supply works normally, the relay is controlled to be in an off state, so that the reverse connection protection unit does not generate loss when the whole system works normally.

When the input power supply is reversely connected, the relay is controlled to be in a suction state (namely a conducting state), and most of reverse connection current flowing from the input power supply flows back to the input power supply through the relay, so that a power tube in the back-end DCDC conversion circuit is protected.

The preferred embodiments of the present application have been described above with reference to the accompanying drawings, and are not thereby limiting the scope of the claims of the present application. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the present application shall fall within the scope of the claims of the present application.

Claims

1. The DCDC circuit system with the input reverse connection protection comprises an input power supply, a DCDC conversion circuit and a load which are connected in sequence; the input power supply is provided with a first output end and a second output end which are connected with the DCDC conversion circuit, and when the input power supply works normally, the voltage of the first output end is higher than that of the second output end; the DCDC conversion circuit is provided with a first power tube; the DCDC circuit system is characterized by further comprising a reverse connection protection unit, wherein the reverse connection protection unit comprises a first electric connection end and a second electric connection end, the first electric connection end is connected with the first output end, and the second electric connection end is connected with the second output end; the reverse connection protection unit is configured to be in an off state when the input power supply works normally and in an on state when the input power supply is in reverse connection.

2. The DCDC circuitry of claim 1, wherein the first power transistor comprises an IGBT or MOS transistor.

3. The DCDC circuitry of claim 1, wherein the reverse protection unit comprises a diode, a cathode of the diode being connected to the first output terminal, an anode of the diode being connected to the second output terminal.

4. The DCDC circuit system of claim 1, wherein the reverse connection protection unit includes a second power tube, a first electrical connection terminal of the second power tube is connected to the first output terminal, a second electrical connection terminal of the second power tube is connected to the second output terminal, and a control terminal of the second power tube receives a first control signal to be turned on or off under the control of the control signal.

5. The DCDC circuitry of claim 4, wherein the second power transistor comprises an IGBT or MOS transistor.

6. The DCDC circuitry of claim 1, wherein the reverse protection unit includes a relay, a first electrical connection of the relay is connected to the first output, a second electrical connection of the relay is connected to the second output, and a control of the relay receives a second control signal to be engaged or disengaged by the control signal.