Output circuit three-state protection device

Abstract

The utility model discloses an output circuit three-state protection device, and the device comprises an overvoltage protection module, the overvoltage protection module comprises a second transistor and an overvoltage control circuit, and the overvoltage control circuit is configured to control the second transistor to be closed when the output voltage of an output port exceeds the voltage of a power supply, so as to enable the output circuit to be disconnected; the current-limiting adjusting module comprises a third transistor, a first current-limiting circuit and a second current-limiting circuit, and the third transistor is configured to control the on-off of the first current-limiting circuit so as to adjust the current of the control end of the first transistor; the short-circuit protection module and the first voltage division circuit are configured to control the third transistor to be closed when the output circuit is short-circuited; the overvoltage protection module, the current-limiting adjustment module and the short-circuit protection module are arranged on the output circuit, so that the circuit is protected when overvoltage, overcurrent and short circuit occur in the output circuit.

Description

Technical Field

[0001] The present application relates to the technical field of power supply output circuit structure, and in particular to a three-state protection device for an output circuit. Background Art

[0002] Traditional Hall sensor power supply circuits cannot effectively protect the circuit when overvoltage, overcurrent, and short circuit occur, thereby causing damage to the output circuit. Summary of the Invention

[0003] In order to overcome the above shortcomings, the purpose of this application is to provide an output circuit three-state protection device, thereby effectively solving the above technical problems.

[0004] To achieve the above objectives, the present application adopts the following technical solution: a three-state protection device for an output circuit, wherein the output circuit includes an output circuit formed by a power supply and an output port, and a first transistor is provided in the circuit connecting the power supply and the output port, and the three-state protection device includes:

[0005] an overvoltage protection module, the overvoltage protection module comprising a second transistor and an overvoltage control circuit, wherein a first electrode of the second transistor is electrically connected to the first transistor, a second electrode of the second transistor is electrically connected to the output port, and a control terminal of the second transistor is electrically connected to the overvoltage control circuit, wherein the overvoltage control circuit is configured to control the second transistor to turn off so as to disconnect the output circuit when an output voltage of the output port exceeds a voltage of the power supply;

[0006] a current limiting regulation module, the current limiting regulation module comprising a third transistor, a first current limiting circuit, and a second current limiting circuit, wherein a first electrode of the third transistor is electrically connected to a ground terminal, a second electrode of the third transistor is electrically connected to the first current limiting circuit, the first current limiting circuit and the second current limiting circuit are electrically connected to a control terminal of the first transistor, and the third transistor is configured to control the on / off state of the first current limiting circuit to regulate the current at the control terminal of the first transistor;

[0007] A short-circuit protection module, the short-circuit protection module includes a first voltage divider circuit and the third transistor, wherein a first end of the first voltage divider circuit is electrically connected to the output circuit, a second end of the first voltage divider circuit is electrically connected to the ground end, a voltage dividing node of the first voltage divider circuit is electrically connected to the control end of the third transistor, and the first voltage divider circuit is configured to control the third transistor to be turned off when the output circuit is short-circuited.

[0008] Furthermore, the overvoltage control circuit includes a fourth transistor, a fifth transistor, a second voltage divider circuit and a third voltage divider circuit, wherein the first end of the second voltage divider circuit is electrically connected to the output circuit, the second end of the second voltage divider circuit is electrically connected to the first electrode of the fourth transistor, the second electrode of the fourth transistor is electrically connected to the control end of the fifth transistor, the fourth transistor is configured to control the on and off of the fifth transistor, the fifth transistor is electrically connected to the third voltage divider circuit, the voltage dividing node of the third voltage divider circuit is electrically connected to the control end of the second transistor, and the fifth transistor is configured to adjust the voltage of the voltage dividing node of the third voltage divider circuit by turning on and off itself to control the on and off of the second transistor.

[0009] Furthermore, the second voltage divider circuit includes a first resistor and a second resistor, and the third voltage divider circuit includes a third resistor and a fourth resistor, wherein:

[0010] The first resistor is electrically connected to the output circuit, the second resistor is electrically connected to the ground terminal, and the fourth transistor is electrically connected to a voltage dividing node between the first resistor and the second resistor.

[0011] The third resistor is connected in parallel with the fifth transistor. The third resistor is short-circuited when the fifth transistor is turned on. The control end of the second transistor is electrically connected to a voltage dividing node between the third resistor and the fourth resistor.

[0012] Furthermore, a fifth resistor is included, a first end of the fifth resistor is electrically connected to the output circuit, a second end of the fifth resistor is electrically connected to the control end of the fifth transistor, and the fifth resistor is configured to control the fifth transistor to be disconnected when the output voltage of the output port does not exceed the voltage of the power supply.

[0013] Furthermore, the first voltage divider circuit includes a sixth resistor and a seventh resistor, the sixth resistor is electrically connected to the output circuit and is located between the first transistor and the second transistor, the seventh resistor is electrically connected to the ground end, and the control end of the third transistor is electrically connected to the voltage divider node between the sixth resistor and the seventh resistor.

[0014] Furthermore, the first current limiting circuit includes an eighth resistor, a first end of the eighth resistor is electrically connected to the third transistor, and a second end of the eighth resistor is electrically connected to the second current limiting circuit.

[0015] Furthermore, the second current limiting circuit includes a ninth resistor and a tenth resistor, and the ninth resistor is connected in parallel with the tenth resistor.

[0016] Furthermore, it includes a first capacitor and an eleventh resistor, wherein the first end of the first capacitor is electrically connected to the connection node between the first current limiting circuit and the second current limiting circuit, and the second end of the first capacitor is electrically connected to the ground end.

[0017] Furthermore, an anti-static module is included. The anti-static module is electrically connected to the output port, and the anti-static module is configured to prevent static electricity from interfering with the output port of the output circuit.

[0018] Furthermore, the anti-static module includes a second capacitor and a third capacitor, the second capacitor is connected in parallel with the third capacitor, the first end of the second capacitor is electrically connected to the output port, the second end of the second capacitor is electrically connected to the ground end, the first end of the third capacitor is electrically connected to the output port, and the second end of the third capacitor is electrically connected to the ground end.

[0019] Beneficial effects

[0020] The present application provides a three-state protection device for an output circuit. By equipping the output circuit with an overvoltage protection module, a current limiting regulation module, and a short-circuit protection module, the device protects the circuit when overvoltage, overcurrent, and short circuit occur in the output circuit, thereby adapting to systems with different operating voltages and improving the reliability of the circuit. The circuit is simple, has reliable performance, and is not prone to failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are intended to facilitate understanding of the technical solutions of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solutions of the present disclosure and do not constitute a limitation of the technical solutions of the present disclosure. The shapes and sizes of the components in the accompanying drawings do not reflect the actual scale and are intended only to illustrate the contents of this application.

[0022] Figure 1 This is a schematic diagram of the structure of a three-state protection circuit for an output circuit. DETAILED DESCRIPTION

[0023] The above scheme is further described below with reference to specific examples. It should be understood that these examples are intended to illustrate the present application and are not intended to limit the scope of the present application. The implementation conditions used in the examples can be further adjusted according to the conditions of the specific manufacturer. The implementation conditions not specified are generally those used in routine experiments.

[0024] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In this article, "electrical connection" includes the situation where constituent elements are connected together through an element with some electrical function. "Element with some electrical function" is not particularly limited as long as it can transfer electrical signals between connected constituent elements. "Element with some electrical function" can be, for example, an electrode or wiring, or a switching element such as a transistor, or other functional elements such as a resistor, inductor or capacitor. “Up,” “down,” “left,” “right,” etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0025] In this application, terms such as "upper," "lower," "inner," and "middle" indicate positions or locations based on those shown in the accompanying drawings. These terms are primarily intended to better describe this application and its embodiments and are not intended to limit the devices, elements, or components indicated to specific positions, or to their construction or operation in a specific position.

[0026] As described in the background art, a conventional Hall sensor power supply circuit cannot effectively protect the circuit when overvoltage, overcurrent, and short circuit occur, thereby causing damage to the output circuit.

[0027] In response to the above content, the inventor provides an output circuit three-state protection device, which includes an output circuit formed by a power supply and an output port, and a first transistor is provided on the circuit connecting the power supply and the output port, and the three-state protection device includes: an overvoltage protection module, the overvoltage protection module includes a second transistor and an overvoltage control circuit, wherein the first electrode of the second transistor is electrically connected to the first transistor, the second electrode of the second transistor is electrically connected to the output port, and the control end of the second transistor is electrically connected to the overvoltage control circuit, and the overvoltage control circuit is configured to control the second transistor to be turned off when the output voltage of the output port exceeds the voltage of the power supply to disconnect the output circuit; a current limiting regulation module, the current limiting regulation module includes a third transistor, a third transistor, a fourth transistor, and a fifth transistor. A current limiting circuit and a second current limiting circuit, wherein the first electrode of the third transistor is electrically connected to the ground terminal, the second electrode of the third transistor is electrically connected to the first current limiting circuit, the first current limiting circuit and the second current limiting circuit are electrically connected to the control terminal of the first transistor, and the third transistor is configured to control the on and off of the first current limiting circuit to adjust the current of the control terminal of the first transistor; a short-circuit protection module, the short-circuit protection module includes a first voltage divider circuit and a third transistor, wherein the first end of the first voltage divider circuit is electrically connected to the output circuit, the second end of the first voltage divider circuit is electrically connected to the ground terminal, the voltage dividing node of the first voltage divider circuit is electrically connected to the control terminal of the third transistor, and the first voltage divider circuit is configured to control the third transistor to be turned off when the output circuit is short-circuited.

[0028] This application protects the circuit when overvoltage, overcurrent and short circuit occur in the output circuit by equipping the output circuit with an overvoltage protection module, a current limiting regulation module and a short-circuit protection module, so as to adapt to systems with different operating voltages and improve the reliability of the circuit. The circuit is simple, has reliable performance and is not prone to failure.

[0029] Next, combine Figure 1 The present application is described exemplarily.

[0030] An embodiment of the present application discloses a three-state protection device for an output circuit, such as Figure 1 As shown,

[0031] The output circuit includes an output power supply POWER, which is used to power the Hall sensor. The output power supply POWER is 5V. It also includes a first transistor Q1, which is a PNP-type triode. It also includes an output port POWER-OUT of the power output circuit. The output power supply POWER is electrically connected to the output port POWER-OUT through the first transistor Q1 to form an output circuit.

[0032] The three-state protection device includes three protection modules:

[0033] The overvoltage protection module includes a second transistor Q2, a first electrode of the second transistor Q2 is electrically connected to the first transistor Q1, a second electrode of the second transistor Q2 is electrically connected to the output port POWER-OUT, and a control end of the second transistor Q2 is electrically connected to the overvoltage control circuit.

[0034] The overvoltage control circuit includes a fourth transistor Q4, a fifth transistor Q5, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5, wherein:

[0035] The first resistor R1 is electrically connected to the output circuit, the second resistor R2 is electrically connected to the ground terminal GND, the fourth transistor Q4 is electrically connected to a voltage dividing node A between the first resistor R1 and the second resistor R2, the fourth transistor Q4 is electrically connected to the control terminal of the fifth transistor Q5, the third resistor R3 is connected in parallel with the fifth transistor Q5, the third resistor R3 is short-circuited when the fifth transistor Q5 is turned on, the control terminal of the second transistor Q2 is electrically connected to a voltage dividing node B between the third resistor R3 and the fourth resistor R4, the fourth resistor R4 is electrically connected to the ground terminal GND, a first end of the fifth resistor R5 is electrically connected to the output circuit, and a second end of the fifth resistor R5 is electrically connected to the control terminal of the fifth transistor Q5. The fifth resistor R5 controls the fifth transistor to be turned off when the output voltage of the output port does not exceed the voltage of the power supply.

[0036] The operating principle of the overvoltage protection module is as follows:

[0037] The first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are all set to 20K.

[0038] When the output circuit is working normally, due to the presence of the fifth resistor R5, the fifth transistor Q5 is not turned on by default. The voltage at the voltage-dividing node A between the first resistor R1 and the second resistor R2 is 2.495V. The fourth transistor Q4 is a diode. When the voltage at point A does not exceed 2.495V, the fourth transistor Q4 is not turned on.

[0039] When the voltage at the output port in the output circuit exceeds the power supply voltage of 5V, an overvoltage condition occurs in the output circuit. The voltage at point A exceeds 2.495V, the fourth transistor Q4 is broken down and turned on, the voltage at the control end of the fifth transistor exceeds 1.1V, and the fifth transistor Q5 is turned on. When the fifth transistor Q5 is turned on, the third resistor R5 connected in parallel with it is short-circuited. At this time, the voltage at the voltage-dividing node B between the third resistor and the fourth resistor is less than 1.1V, and the second transistor Q2 switches from on to off. At this time, the output circuit is disconnected and enters the overvoltage protection stage.

[0040] The current limiting regulation module and the short circuit protection module include a third transistor Q3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11 and a first capacitor C1, wherein:

[0041] The sixth resistor R6 is electrically connected to the output circuit and is located between the first transistor Q1 and the second transistor Q2. The seventh resistor R7 is electrically connected to the ground terminal GND. The control terminal of the third transistor Q3 is electrically connected to the voltage divider node B between the sixth resistor R6 and the seventh resistor R7. The first electrode of the third transistor Q3 is electrically connected to the eighth resistor R8, and the second electrode of the third transistor Q3 is electrically connected to the ground terminal GND. The ninth resistor R9 and the tenth resistor R10 form a parallel circuit and are electrically connected to the control terminal of the first transistor Q1. The ninth resistor R9 and the tenth resistor R10 also form a parallel circuit and are electrically connected to the eighth resistor R8. The first end of the first capacitor C1 is electrically connected to a connecting node between the parallel circuit formed by the ninth resistor R9 and the tenth resistor R10 and the eighth resistor R8. The second end of the first capacitor C1 is electrically connected to the ground terminal GND.

[0042] Set the resistance values ​​of R9 and R10 to 1K, and the resistance values ​​of R6 and R7 to 20K. When the output power supply POWER injects voltage, the first capacitor C1 is equivalent to a short circuit when powered on. The PNP transistor Q1 will be turned on to the GND travel loop through R9, R10 and C1, and an instantaneous voltage drop will be generated to meet the conduction voltage drop of the Q1 transistor. After the transistor Q1 is turned on, the 5V voltage passes through the output circuit and is divided by R6 and R7 to obtain a voltage greater than 1.1V to turn on Q3 to make R8 turn on to ground, thus forming a self-holding open output circuit. The output voltage reaches Q2. According to the voltage division of R3 and R4, the voltage at the control end of Q2 is greater than 1.1V, Q2 is fully turned on, and the output port POWER-OUT outputs normally.

[0043] After Q1 is continuously turned on, the function of R8, R9, and R10 is to adjust the current Ib at the control terminal of transistor Q1. The β of transistor Q1 is 20, so that the maximum current of the output channel Ic of transistor Q1 is (βI b) mA, thereby realizing the current limiting output function.

[0044] Q3, R6, and R7 form a short-circuit detection circuit. When the circuit is short-circuited to ground, the voltage at the control terminal of transistor Q3 is less than 1.1V, turning off transistor Q3. After transistor Q3 is turned off, resistor R8 is disconnected from the circuit. Resistors R9 and R10 pull the voltage at the control terminal of transistor Q1 down to ground, turning off transistor Q1. Q1 can switch on and off based on feedback from Q4 to achieve short-circuit protection. Resistor R9 is connected in parallel with capacitor C1 to consume the charge in capacitor C1 to achieve short-circuit self-recovery.

[0045] In some embodiments, the output circuit protection device also includes an anti-static module, which includes a second capacitor and a third capacitor, the second capacitor and the third capacitor are connected in parallel, the first end of the second capacitor is electrically connected to the output port, the second end of the second capacitor is electrically connected to the ground end, the first end of the third capacitor is electrically connected to the output port, and the second end of the third capacitor is electrically connected to the ground end. The anti-static module is used to prevent static electricity from interfering with the output port of the output circuit.

[0046] The above embodiments are intended only to illustrate the technical concepts and features of this application. Their purpose is to enable those familiar with the art to understand the content of this application and implement it accordingly. They are not intended to limit the scope of protection of this application. Any equivalent changes or modifications made in accordance with the spirit of this application shall be included in the scope of protection of this application.

Claims

1. A three-state protection device for an output circuit, wherein the output circuit includes an output circuit formed by a power supply and an output port, and a first transistor is provided in the circuit connecting the power supply and the output port, characterized in that: The three-state protection device comprises: an overvoltage protection module, the overvoltage protection module comprising a second transistor and an overvoltage control circuit, wherein a first electrode of the second transistor is electrically connected to the first transistor, a second electrode of the second transistor is electrically connected to the output port, and a control terminal of the second transistor is electrically connected to the overvoltage control circuit, wherein the overvoltage control circuit is configured to control the second transistor to turn off so as to disconnect the output circuit when an output voltage of the output port exceeds a voltage of the power supply; a current limiting regulation module, the current limiting regulation module comprising a third transistor, a first current limiting circuit, and a second current limiting circuit, wherein a first electrode of the third transistor is electrically connected to a ground terminal, a second electrode of the third transistor is electrically connected to the first current limiting circuit, the first current limiting circuit and the second current limiting circuit are electrically connected to a control terminal of the first transistor, and the third transistor is configured to control the on / off state of the first current limiting circuit to regulate the current at the control terminal of the first transistor; A short-circuit protection module, the short-circuit protection module includes a first voltage divider circuit and the third transistor, wherein a first end of the first voltage divider circuit is electrically connected to the output circuit, a second end of the first voltage divider circuit is electrically connected to the ground end, a voltage dividing node of the first voltage divider circuit is electrically connected to the control end of the third transistor, and the first voltage divider circuit is configured to control the third transistor to be turned off when the output circuit is short-circuited.

2. The output circuit tri-state protection device according to claim 1, wherein: The overvoltage control circuit includes a fourth transistor, a fifth transistor, a second voltage divider circuit and a third voltage divider circuit, wherein the first end of the second voltage divider circuit is electrically connected to the output circuit, the second end of the second voltage divider circuit is electrically connected to the first electrode of the fourth transistor, the second electrode of the fourth transistor is electrically connected to the control end of the fifth transistor, the fourth transistor is configured to control the on and off of the fifth transistor, the fifth transistor is electrically connected to the third voltage divider circuit, the voltage dividing node of the third voltage divider circuit is electrically connected to the control end of the second transistor, and the fifth transistor is configured to adjust the voltage of the voltage dividing node of the third voltage divider circuit by turning on and off itself to control the on and off of the second transistor.

3. The output circuit tri-state protection device according to claim 2, wherein: The second voltage divider circuit includes a first resistor and a second resistor, and the third voltage divider circuit includes a third resistor and a fourth resistor, wherein: The first resistor is electrically connected to the output circuit, the second resistor is electrically connected to the ground terminal, and the fourth transistor is electrically connected to a voltage dividing node between the first resistor and the second resistor. The third resistor is connected in parallel with the fifth transistor. The third resistor is short-circuited when the fifth transistor is turned on. The control end of the second transistor is electrically connected to a voltage dividing node between the third resistor and the fourth resistor.

4. The output circuit tri-state protection device according to claim 3, wherein: It also includes a fifth resistor, a first end of the fifth resistor is electrically connected to the output circuit, a second end of the fifth resistor is electrically connected to the control end of the fifth transistor, and the fifth resistor is configured to control the fifth transistor to be disconnected when the output voltage of the output port does not exceed the voltage of the power supply.

5. The output circuit tri-state protection device according to claim 1, wherein: The first voltage divider circuit includes a sixth resistor and a seventh resistor, the sixth resistor is electrically connected to the output circuit and is located between the first transistor and the second transistor, the seventh resistor is electrically connected to the ground end, and the control end of the third transistor is electrically connected to the voltage divider node between the sixth resistor and the seventh resistor.

6. The output circuit tri-state protection device according to claim 1, wherein: The first current limiting circuit includes an eighth resistor, a first end of the eighth resistor is electrically connected to the third transistor, and a second end of the eighth resistor is electrically connected to the second current limiting circuit.

7. The output circuit tri-state protection device according to claim 6, wherein: The second current limiting circuit includes a ninth resistor and a tenth resistor, and the ninth resistor is connected in parallel with the tenth resistor.

8. The output circuit tri-state protection device according to claim 7, wherein: It also includes a first capacitor and an eleventh resistor, wherein the first end of the first capacitor is electrically connected to the connection node between the first current limiting circuit and the second current limiting circuit, and the second end of the first capacitor is electrically connected to the ground end.

9. The output circuit tri-state protection device according to claim 1, wherein: It also includes an anti-static module, which is electrically connected to the output port and is configured to prevent static electricity from interfering with the output port of the output circuit.

10. The output circuit tri-state protection device according to claim 9, wherein: The anti-static module includes a second capacitor and a third capacitor, the second capacitor is connected in parallel with the third capacitor, the first end of the second capacitor is electrically connected to the output port, the second end of the second capacitor is electrically connected to the ground end, the first end of the third capacitor is electrically connected to the output port, and the second end of the third capacitor is electrically connected to the ground end.

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