Protection circuit, electronic apparatus, and vehicle

Abstract

The invention discloses a protection circuit, electronic equipment and a vehicle, relates to the technical field of automobiles, and aims to solve the problem of load damage caused by abnormal power supply between power loads. The protection circuit comprises a switching circuit, a comparison latch circuit and a current detection circuit. The first end of the switching circuit is connected with a power supply, and the second end of the switching circuit is connected with a load. The current detection circuit is used for collecting current between the switching circuit and the load, generating detection voltage according to the current and outputting the detection voltage. The second end of the comparison latch circuit is connected with the third end of the switching circuit. And the comparison latch circuit is used for acquiring the detection voltage and the first reference voltage, and continuously sending a turn-off control signal to the switching circuit when the detection voltage is greater than the first reference voltage, so as to control the continuous turn-off of the first end and the second end of the switching circuit.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to protection circuits, electronic equipment and vehicles. Background Art

[0002] When the power supply is supplying power to the load, if the power supply current provided by the power supply to the load is abnormal or there is a short circuit between the power supply and the load, the current flowing through the load may exceed the rated current of the load. In this case, the power supply and the load need to be disconnected to avoid damage to the load due to the power supply abnormality. Summary of the invention

[0003] The object of the present invention is to provide a protection circuit, an electronic device, and a vehicle, aiming to avoid the problem that the load is damaged due to abnormal power supply between a power source and a load.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] The invention provides a protection circuit, comprising a switch circuit, a comparison latch circuit and a current detection circuit.

[0006] The first end of the switch circuit is connected to the power supply, and the second end of the switch circuit is connected to the load. The on-off of the first end and the second end of the switch circuit is used to control the on-off between the power supply and the load.

[0007] The first end of the current detection circuit is connected to the second end of the switch circuit, the second end of the current detection circuit is connected to the load, and the third end of the current detection circuit is connected to the first end of the comparison latch circuit. The current detection circuit is used to collect the current between the switch circuit and the load, and the current detection circuit is also used to generate a detection voltage according to the current and output the detection voltage.

[0008] The second end of the comparison latch circuit is connected to the third end of the switch circuit. The comparison latch circuit is used to obtain the detection voltage and the first reference voltage, and when the detection voltage is greater than the first reference voltage, continuously sends a shutdown control signal to the switch circuit to control the first end and the second end of the switch circuit to be continuously shut down.

[0009] The protection circuit provided in the embodiment of the present application can detect the current between the switch circuit and the load in real time by setting a current detection circuit, and generate a detection voltage according to the current between the switch circuit and the load, and the comparison latch circuit can judge whether the current flowing through the load is within a set range based on the detection voltage and the first reference voltage. The set current range can be set according to the rated current of the load, and the rated current of the load is within the set current range, and when the current flowing through the load is within the set current range, the load can work normally.

[0010] When the detection voltage is greater than the first reference voltage, the current between the switch circuit and the load exceeds the maximum value of the set current range. At this time, the current flowing through the load is too large, and the comparison latch circuit continues to send a shutdown control signal to the switch circuit to control the first end and the second end of the switch circuit to be continuously shut down, so as to disconnect the power supply and the load, thereby avoiding excessive current flowing through the load, causing damage or even destruction of the load.

[0011] In some embodiments, the protection circuit further includes: a reset circuit and a control circuit. The first end of the reset circuit is connected to the first end of the comparison latch circuit, and the second end of the reset circuit is connected to the control circuit. The control circuit is used to send a reset signal to the reset circuit. The reset circuit is used to output a reset reference voltage to the first end of the comparison latch circuit under the control of the reset signal, and the reset reference voltage is less than the first reference voltage; the comparison latch circuit is also used to stop outputting the shutdown control signal when receiving the reset reference voltage.

[0012] In some embodiments, the control circuit is connected to the fourth terminal of the current detection circuit and the fourth terminal of the switch circuit. The current detection circuit is also used to transmit the collected current to the control circuit. The control circuit is used to send a control signal to the fourth terminal of the switch circuit when the current is greater than the threshold current to control the first terminal and the second terminal of the switch circuit to be turned off.

[0013] In some embodiments, the protection circuit further includes a first voltage detection circuit and / or a second voltage detection circuit.

[0014] The first end of the first voltage detection circuit is connected to the first end of the switch circuit, and the second end of the first voltage detection circuit is connected to the control circuit; the first voltage detection circuit is used to detect the output voltage of the power supply and transmit the output voltage of the power supply to the control circuit. The control circuit is used to control the first end and the second end of the switch circuit to be turned off when the output voltage of the power supply is less than the second reference voltage or greater than the third reference voltage.

[0015] The first end of the second voltage detection circuit is connected to the second end of the switch circuit, and the second end of the second voltage detection circuit is connected to the control circuit; the second voltage detection circuit is used to detect the output voltage of the switch circuit and transmit the output voltage of the switch circuit to the control circuit. The control circuit is used to control the first end and the second end of the switch circuit to be turned off when the output voltage is less than the fourth reference voltage or greater than the fifth reference voltage.

[0016] In some further embodiments, when the protection circuit includes a first voltage detection circuit and a second voltage detection circuit, the control circuit is also used to control the first end and the second end of the switching circuit to be turned off when the difference between the output voltage of the power supply and the output voltage of the switching circuit meets a predetermined condition.

[0017] In some embodiments, the third terminal of the first voltage detection circuit is connected to the control circuit. The control circuit is used to transmit a detection control signal to the third terminal of the first voltage detection circuit when the first terminal and the second terminal of the switch circuit are turned on, so as to control the first terminal of the first voltage detection circuit to be turned on with the first terminal of the switch circuit.

[0018] In some embodiments, the protection circuit further includes a reference circuit connected to the third terminal of the comparison latch circuit. The reference circuit is used to output a first reference voltage to the comparison latch circuit.

[0019] In some embodiments, the protection circuit further includes an anti-reverse circuit connected between the power supply and the switch circuit, and used to control the current to flow unidirectionally from the power supply to the switch circuit.

[0020] In some embodiments, the switch circuit includes: a switch subcircuit and a driver subcircuit. The first end of the switch subcircuit is connected to the first end of the switch circuit, and the second end of the switch subcircuit is connected to the second end of the switch circuit. The first end of the driver subcircuit is connected to the third end of the switch circuit, and the second end of the driver subcircuit is connected to the fourth end of the switch circuit. The third end of the switch subcircuit is connected to the third end of the driver subcircuit. The driver subcircuit is used to control the switch subcircuit to turn off the first end and the second end of the switch circuit based on the shutdown control signal.

[0021] In some embodiments, the switch subcircuit includes a first switch element, a control electrode of the first switch element is connected to the third end of the switch subcircuit, a first electrode of the first switch element is connected to the first end of the switch subcircuit, and a second electrode of the first switch element is connected to the second end of the switch subcircuit.

[0022] In some embodiments, the switch subcircuit further includes: at least one of a first diode, a first resistor, and a first capacitor.

[0023] A first electrode of the first diode is connected to the control electrode of the first switching element, and a second electrode of the first diode is connected to the first electrode of the first switching element.

[0024] A first end of the first resistor is connected to a control electrode of the first switch element, and a second end of the first resistor is connected to a first electrode of the first switch element.

[0025] A first end of the first capacitor is connected to a control electrode of the first switch element, and a second end of the first capacitor is connected to a first electrode of the first switch element.

[0026] In some embodiments, the switch subcircuit further includes: a second resistor, a second switch element, and a second diode.

[0027] The control electrode of the second switch element is connected to the third end of the switch subcircuit, the first electrode of the second switch element is connected to the first end of the switch subcircuit, and the second electrode of the second switch element is connected to the control electrode of the first switch element.

[0028] A first end of the second resistor is connected to a first end of the switch subcircuit, and a second end of the second resistor is connected to a control electrode of the second switch element.

[0029] The first end of the second diode is connected to the second electrode of the second switch element, and the second end of the second diode is connected to the control electrode of the first switch element.

[0030] In some embodiments, the driving subcircuit includes: a third switch element and a fourth switch element. The control electrode of the third switch element is connected to the second end of the driving subcircuit, the first electrode of the third switch element is connected to the third end of the driving subcircuit, and the second electrode of the third switch element is connected to the ground end. The control electrode of the fourth switch element is connected to the first end of the driving subcircuit, the first electrode of the fourth switch element is connected to the control electrode of the third switch element, and the second electrode of the fourth switch element is connected to the ground end.

[0031] In some embodiments, the driving subcircuit further includes: a third resistor and a fourth resistor. A first end of the third resistor is connected to the control electrode of the third switch element, a second end of the third resistor is connected to a first end of the fourth resistor, and a second end of the fourth resistor is connected to the ground terminal. A common end of the third resistor and the fourth resistor is a second end of the driving subcircuit.

[0032] In some embodiments, the driving subcircuit further includes: a fifth resistor and a sixth resistor. The first end of the fifth resistor is connected to the control electrode of the third switch element, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is connected to the ground terminal. The common terminal of the fifth resistor and the sixth resistor is the fifth end of the switch circuit, and the fifth end of the switch circuit is connected to the control circuit. The fifth end of the switch circuit is used to output a feedback signal to the control circuit, and the feedback signal is used to characterize the conduction state of the fourth switch element.

[0033] In some embodiments, the driving sub-circuit further includes a nineteenth resistor, a first end of the nineteenth resistor is connected to the second electrode of the third switch element, and a second end of the nineteenth resistor is connected to the third end of the switch sub-circuit.

[0034] In some embodiments, the driving sub-circuit further includes a fifth capacitor, a first end of the fifth capacitor is connected to the control electrode of the third switch element, and a second end of the fifth capacitor is connected to the ground end.

[0035] In some embodiments, the driving sub-circuit further includes a twentieth capacitor, a first end of the twentieth capacitor is connected to the control electrode of the fourth switch element, and a second end of the twentieth capacitor is connected to the ground end.

[0036] In some embodiments, the driving sub-circuit further includes a twenty-first resistor, a first end of the twenty-first resistor is connected to the control terminal of the fourth switch element, and a second end of the twenty-first resistor is connected to the second end of the comparison latch circuit.

[0037] In some embodiments, the comparison latch circuit includes: a first chip, a seventh resistor and a third diode. The first input terminal of the first chip is connected to the first terminal of the comparison latch circuit, the second input terminal of the first chip is connected to the third terminal of the comparison latch circuit, and the output terminal of the first chip is connected to the second terminal of the switch circuit. The first terminal of the seventh resistor is connected to the output terminal of the first chip, the second terminal of the seventh resistor is connected to the first terminal of the third diode, and the second terminal of the third diode is connected to the first input terminal of the first chip.

[0038] In some embodiments, the comparison latch circuit also includes a fifth switching element, a control electrode of the fifth switching element is connected to the output end of the first chip, a first electrode of the fifth switching element is connected to the power signal end, and a second electrode of the fifth switching element is connected to the second end of the comparison latch circuit.

[0039] In some embodiments, the current detection circuit includes: a second chip and an eighth resistor. The first end of the eighth resistor is connected to the first end of the current detection circuit, and the second end of the eighth resistor is connected to the second end of the current detection circuit. The first input end of the second chip is connected to the first end of the eighth resistor, the second input end of the second chip is connected to the second end of the eighth resistor, and the output end of the second chip is connected to the third end of the current detection circuit.

[0040] In some embodiments, the current detection circuit further includes: a twenty-third resistor and a twenty-fourth resistor. The first end of the twenty-third resistor is connected to the first end of the eighth resistor, and the second end of the twenty-third resistor is connected to the first input end of the second chip. The first end of the twenty-fourth resistor is connected to the first end of the eighth resistor, and the second end of the twenty-fourth resistor is connected to the second input end of the second chip.

[0041] In some embodiments, the current detection circuit further includes: a sixth capacitor, a first end of the sixth capacitor is connected to the first end of the current detection circuit, and a second end of the sixth capacitor is connected to the second end of the current detection circuit.

[0042] In some embodiments, the current detection circuit further includes: a twenty-fifth resistor and a seventh capacitor. The first end of the twenty-fifth resistor is connected to the output end of the second chip, the second end of the twenty-fifth resistor is connected to the first end of the seventh capacitor, and the second end of the seventh capacitor is connected to the ground end. The common end of the twenty-fifth resistor and the seventh capacitor is the fourth end of the current detection circuit.

[0043] In some embodiments, the twenty-sixth resistor and the eighth capacitor. The first end of the twenty-sixth resistor is connected to the output end of the second chip, the second end of the twenty-sixth resistor is connected to the first end of the comparison latch circuit. The first end of the eighth capacitor is connected to the first end of the comparison latch circuit, and the second end of the eighth capacitor is connected to the ground terminal.

[0044] In some embodiments, the reference circuit includes: a seventeenth resistor and an eighteenth resistor. The first end of the seventeenth resistor is connected to the ground terminal, the second end of the seventeenth resistor is connected to the first end of the eighteenth resistor, and the second end of the eighteenth resistor is connected to the power signal terminal. The common terminal EF of the seventeenth resistor and the eighteenth resistor is connected to the third end of the comparison latch circuit.

[0045] In some embodiments, the reset circuit includes: a sixth switch element, a ninth resistor, and a tenth resistor. The first end of the ninth resistor is connected to the ground end, the second end of the ninth resistor is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the control electrode of the sixth switch element, the first electrode of the sixth switch element is connected to the first end of the reset circuit, and the second electrode of the sixth switch element is connected to the ground end. The common end of the ninth resistor and the tenth resistor is the second end of the reset circuit.

[0046] In some embodiments, the first voltage detection circuit includes: an eleventh resistor, a twelfth resistor, and a second capacitor. The first end of the eleventh resistor is connected to the first end of the first voltage detection circuit, the second end of the eleventh resistor is connected to the first end of the twelfth resistor, and the second end of the twelfth resistor is connected to the ground terminal. The common end of the eleventh resistor and the twelfth resistor is the second end of the first voltage detection circuit. The first end of the second capacitor is connected to the second end of the first voltage detection circuit, and the second end of the second capacitor is connected to the ground terminal.

[0047] In some embodiments, the first voltage detection circuit further includes: a seventh switch element, an eighth switch element, a thirteenth resistor, and a fourteenth resistor. The first end of the thirteenth resistor is connected to the third end of the first voltage detection circuit, the second end of the thirteenth resistor is connected to the first end of the fourteenth resistor, and the second end of the fourteenth resistor is connected to the ground end. The common end of the thirteenth resistor and the fourteenth resistor is connected to the control electrode of the eighth switch element, the first electrode of the eighth switch element is connected to the control electrode of the seventh switch element, and the second electrode of the eighth switch element is connected to the ground end. The first electrode of the seventh switch element is connected to the first end of the first voltage detection circuit, and the second electrode of the seventh switch element is connected to the first end of the eleventh resistor.

[0048] In some embodiments, the first end of the twenty-seventh resistor is connected to the control electrode of the seventh switch element, the first electrode of the seventh switch element is connected to the first end of the switch circuit, and the second electrode of the seventh switch element is connected to the first end of the eleventh resistor.

[0049] In some embodiments, the second voltage detection circuit includes: a fifteenth resistor, a sixteenth resistor and a third capacitor. The first end of the fifteenth resistor is connected to the first end of the second voltage detection circuit, the second end of the fifteenth resistor is connected to the first end of the sixteenth resistor, and the second end of the sixteenth resistor is connected to the ground terminal. The common terminal of the fifteenth resistor and the sixteenth resistor is the second end of the second voltage detection circuit. The first end of the third capacitor is connected to the second end of the first voltage detection circuit, and the second end of the third capacitor is connected to the ground terminal. The second voltage signal terminal is the common terminal of the twenty-third resistor and the twenty-fourth resistor.

[0050] In some embodiments, the protection circuit further includes a ninth capacitor, a first end of the ninth capacitor is connected to the first end of the switch circuit, and a second end of the ninth capacitor is connected to the ground end.

[0051] The present invention further provides an electronic device, which includes a power supply, a load, and a protection circuit as provided in any of the above embodiments, wherein the protection circuit is connected between the power supply and the load.

[0052] The present invention further provides a vehicle, which comprises a vehicle body and the electronic device as described in the above embodiment, wherein the electronic device is arranged in the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 is a schematic diagram of a protection circuit according to some embodiments;

[0055] Figure 2 is a schematic structural diagram of a protection circuit according to some other embodiments;

[0056] Figure 3 Based on Figure 2 The circuit structure diagram of the protection circuit shown;

[0057] Figure 4 Based on Figure 2 A circuit diagram of a switch circuit of the protection circuit shown;

[0058] Figure 5 Based on Figure 2 The circuit structure diagram of the comparison latch circuit of the protection circuit shown;

[0059] Figure 6 Based on Figure 2 The circuit structure diagram of the current detection circuit of the protection circuit shown;

[0060] Figure 7 Based on Figure 2 The circuit structure diagram of the reference circuit of the protection circuit shown;

[0061] Figure 8 Based on Figure 2 A circuit structure diagram of a reset circuit of the protection circuit shown;

[0062] Fig. 9 Based on Figure 2 The circuit structure diagram of the first voltage detection circuit and the second voltage detection circuit of the protection circuit shown.

[0063] Reference numerals:

[0064] 100. Switching circuit;

[0065] 110. Switch subcircuit;

[0066] Q1, first switch element; D1, first diode; C1, first capacitor; R1, first resistor; Q2, second switch element; D2, second diode; R2, second resistor;

[0067] 120. driving sub-circuit;

[0068] Q3, third switch element; Q4, fourth switch element; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R19, nineteenth resistor; R20, twentieth resistor; R21, twenty-first resistor; C5, fifth capacitor;

[0069] 200, comparison latch circuit;

[0070] U1, first chip; D3, third diode; R7, seventh resistor; R22, twenty-second resistor; C5, fifth capacitor; Q5, fifth switch element;

[0071] 300, current detection circuit;

[0072] U2, second chip; R8, eighth resistor; R23, twenty-third resistor; R24, twenty-fourth resistor; R25, twenty-fifth resistor; R26, twenty-sixth resistor; C6, sixth capacitor; C7, seventh capacitor; C8, eighth capacitor;

[0073] 400. Reference circuit;

[0074] R17, the seventeenth resistor; R18, the eighteenth resistor;

[0075] 500, reset circuit;

[0076] Q6, sixth switch element; R9, ninth resistor; R10, tenth resistor;

[0077] 600, a first voltage detection circuit;

[0078] Q7, the seventh switch element; Q8, the eighth switch element; R11, the eleventh resistor; R12, the twelfth resistor; R13, the thirteenth resistor; R14, the fourteenth resistor; R27, the twenty-seventh resistor; C2, the second capacitor;

[0079] 700, a second voltage detection circuit;

[0080] R15, the fifteenth resistor; R16, the sixteenth resistor; C3, the third capacitor;

[0081] 800, anti-reverse circuit;

[0082] Q9, ninth switching element;

[0083] 900. Control circuit. DETAILED DESCRIPTION

[0084] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0085] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside" and the like indicate directions or positional relationships based on the directions or relative positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. Unless otherwise specified, the above-mentioned directional description can be flexibly set in the process of actual application under the condition that the relative positional relationship shown in the accompanying drawings is satisfied.

[0086] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0087] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0088] In the embodiments of the present invention, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, article or device including the element.

[0089] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0090] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0091] Some embodiments of the present invention provide an electronic device.

[0092] In some embodiments, the electronic device includes a protection circuit, which is connected between a power source and a load and controls the power source and the load to be disconnected when a current provided by the power source to the load exceeds a threshold current.

[0093] The supply voltage of the power supply matches the rated voltage of the load connected to it. The current flowing through the load is called the load current. When the actual output current of the power supply is greater than the rated output current of the power supply, or there is a short circuit between the power supply and the load, the load current may exceed the rated current of the load, which may cause damage or even destruction of the load.

[0094] By setting up a protection circuit connected between the power supply and the load, when an overcurrent or short circuit occurs between the power supply and the load, the protection circuit can disconnect the connection between the power supply and the load, thereby preventing excessive current from flowing through the load and causing damage to the load or even destroying the load.

[0095] Exemplarily, the electronic device further includes at least one of a power source and a load.

[0096] The electronic device provided in this embodiment can also be applied to a power distribution system to prevent electrical fires and equipment damage and ensure electrical safety.

[0097] The electronic device provided in this embodiment can also be used in public infrastructure such as traffic lights, street lights and communication base stations to ensure the stable operation of the public infrastructure.

[0098] The electronic device provided in this embodiment can be applied to motor control, transformer protection or mechanical drive system, and can prevent equipment damage caused by overload, short circuit or ground fault.

[0099] Specifically, taking the application of electronic equipment in a vehicle as an example, the vehicle may include one power source or multiple (two or more) power sources. One power source may be connected to one load or multiple (two or more) loads. Power sources include but are not limited to power batteries or storage batteries, etc., and loads include but are not limited to electrical devices such as vehicle lighting, air conditioners, and domain controllers.

[0100] The application scenarios of the electronic device include but are not limited to the above examples. The above is an exemplary description of some specific application scenarios of the present disclosure, and the present disclosure does not limit this.

[0101] In some embodiments, Figure 1 As shown, the protection circuit includes a switch circuit, a current detection circuit, a comparison circuit and a reference generation circuit. The first end of the switch circuit is connected to the power supply, the second end of the switch circuit is connected to the load, and the on and off of the first end and the second end of the switch circuit are used to control the on and off between the power supply and the load.

[0102] The first end of the current detection circuit is connected to the power supply, and the second end of the current detection circuit is connected to the first input end of the comparison circuit; the first end of the reference generation circuit is connected to the power supply, and the second end of the reference generation circuit is connected to the second input end of the comparison circuit; the output end of the comparison circuit is connected to the third end of the switch circuit.

[0103] The current detection circuit is used to detect the output current of the power supply and output a first detection signal according to the detected current; the reference generation circuit is used to obtain the power supply type and output a second detection signal according to the power supply type; the comparison circuit is used to obtain the first detection signal and the second detection signal, and when the first detection signal and the second detection signal do not match, send a shutdown control signal to the switch circuit to control the first end and the second end of the switch circuit to shut down.

[0104] The first detection signal is used to characterize the current flowing through the switching circuit (the current output current of the power supply), and the second detection signal is used to characterize the rated output current of the power supply. The first detection signal can be a detection current, and correspondingly, the second detection signal is a reference current; or, the first detection signal can be a detection voltage generated based on the detection current, and correspondingly, the second detection signal is a reference voltage. The comparison circuit can determine whether there is an overcurrent between the power supply and the load by comparing the detection current and the reference current, or it can determine whether there is an overcurrent between the power supply and the load by comparing the detection voltage and the reference voltage.

[0105] Here are some exemplary descriptions of possible implementations of the present disclosure, which can be adaptively designed according to actual needs, and the present disclosure does not limit this.

[0106] Based on this, when the first detection signal and the second detection signal match, the current flowing through the switching circuit is less than the rated output current of the power supply, or the current flowing through the switching circuit is the same or approximately the same as the rated output current of the power supply, the first end and the second end of the switching circuit remain turned on, and the power supply is connected to the load to enable the power supply to supply power to the load.

[0107] When the first detection signal and the second detection signal do not match, the current flowing through the switching circuit is greater than the rated output current of the power supply. At this time, the current flowing through the load is large, which may cause damage to the load. The comparison circuit outputs a shutdown control signal to control the first and second ends of the switching circuit to shut down, thereby disconnecting the power supply and the load to avoid damage to the load.

[0108] However, after the first end and the second end of the switching circuit are turned off, the power supply and the load are disconnected, and the current between the power supply and the switching circuit is 0. The current detection circuit detects that there is no overcurrent between the power supply and the load, and the comparison circuit does not output a shutdown control signal. The first end and the second end of the switching circuit will be turned on again, but at this time the current flowing through the load may still be overcurrent. Based on the foregoing, the first end and the second end of the switching circuit will be disconnected again.

[0109] In summary, in the protection circuit of this embodiment, when an overcurrent condition exists between the power supply and the load, after the comparison circuit outputs a shutdown control signal to control the first end and the second end of the switch circuit to shut down, the comparison circuit will determine that there is no overcurrent condition between the power supply and the load, and the comparison circuit does not output a shutdown control signal. The first end and the second end of the switch circuit are turned on again, but at this time the output current of the power supply may still be greater than the rated current, and the comparison circuit again outputs a shutdown control signal to control the first end and the second end of the switch circuit to shut down.

[0110] In this way, when a power failure occurs or there is an abnormal situation such as a short circuit between the power supply and the load, the first end and the second end of the switch circuit will repeatedly turn on and off without eliminating the fault, which may cause damage to the power supply and / or load.

[0111] Based on this, in some embodiments, Figure 2 As shown, the protection circuit includes: a switch circuit 100, a comparison latch circuit 200 and a current detection circuit 300. The first end of the switch circuit 100 is connected to the power supply, and the second end of the switch circuit 100 is connected to the load. The on and off of the first end and the second end of the switch circuit 100 are used to control the on and off between the power supply and the load.

[0112] The first end of the current detection circuit 300 is connected to the second end of the switch circuit 100, the second end of the current detection circuit 300 is connected to the load, and the third end of the current detection circuit 300 is connected to the first end of the comparison latch circuit 200. The current detection circuit 300 is used to collect the current between the switch circuit 100 and the load, and the current detection circuit 300 is also used to generate a detection voltage according to the current and output the detection voltage.

[0113] The second end of the comparison latch circuit 200 is connected to the third end of the switch circuit 100. The comparison latch circuit 200 is used to obtain the detection voltage and the first reference voltage, and when the detection voltage is greater than the first reference voltage, continuously sends a shutdown control signal to the switch circuit 100 to control the first end and the second end of the switch circuit 100 to be continuously shut down.

[0114] Exemplarily, the threshold current may be adaptively designed according to the rated current of the load, and the threshold current may be the same as the rated current of the load, or the same as the maximum current allowed to flow through the load when the load is working normally.

[0115] For example, the rated current of the load is 2A, and the maximum current allowed to flow through the load when the load is working normally is 2.5A, then the threshold current can be set to 2A or 2.5A. The selection of the threshold current can be adaptively designed according to actual needs. Here is an exemplary description of some specific embodiments of the present disclosure, and the present invention is not limited to this.

[0116] Exemplarily, the current detection circuit 300 detects the current flowing through the load, converts it into a corresponding analog voltage signal (a detection voltage generated by the current detection circuit according to the current), and outputs the detection voltage to the comparison latch circuit 200 .

[0117] Based on the above, the first end of the switch circuit 100 is connected to the first end of the protection circuit, and the second end of the switch circuit 100 is connected to the second end of the protection circuit. By controlling the first end and the second end of the switch circuit 100 to be turned on or off, the power supply and the load can be turned on or off.

[0118] Figure 1 In the protection circuit, the current detection circuit is used to collect the current between the power supply and the switching circuit. In this way, when a fault occurs in the switching circuit, there may be a deviation between the current between the switching circuit and the load and the current between the power supply and the switching circuit. In this way, the judgment result of the comparison circuit may be affected by the detection signal provided by the current detection circuit and become inaccurate.

[0119] In this embodiment, Figure 2 As shown, the current detection circuit 300 is used to detect the current between the switch circuit 100 and the load. In this way, the current detection circuit 300 can more accurately collect the current flowing through the load, ensure that the comparison latch circuit 300 can more accurately judge whether the current flowing through the load is within the set range, and improve the reliability of the protection circuit.

[0120] At the same time, by adopting such a connection mode, when a fault occurs in the current detection circuit 300, the first end and the second end of the switch circuit 100 can be turned off to protect the load and reduce the power consumption of the electronic device in the sleep state.

[0121] In this embodiment, Figure 2 As shown, by setting the comparison latch circuit 200, when the current between the switch circuit 100 and the load exceeds the threshold current, the comparison latch circuit 200 can continuously send a shutdown control signal to the switch circuit 100 to control the first end and the second end of the switch circuit 100 to be continuously shut down, so that the power supply and the load are continuously disconnected, thereby avoiding the problem of repeated conduction and disconnection between the power supply and the load causing load damage when the overcurrent condition is not resolved.

[0122] Exemplarily, the set current range described in this embodiment can be set according to the rated current of the load. When the rated current of the load is within the set current range and the current flowing through the load is within the set current range, the load can operate normally.

[0123] Exemplarily, the first reference voltage described in this embodiment can be used to represent that when the current flowing through the load is the maximum value of the set current range, the detection voltage is generated according to the current between the switch circuit 100 and the load. When the detection voltage is equal to the first reference voltage, the current flowing through the load is within the set current range; when the detection voltage is greater than the first reference voltage, the current flowing through the load exceeds the maximum value of the set current range.

[0124] When the detection voltage is greater than the first reference voltage, the current between the switch circuit and the load exceeds the maximum value of the set current range. At this time, the current flowing through the load is too large, and the comparison latch circuit continues to send a shutdown control signal to the switch circuit to control the first end and the second end of the switch circuit to be continuously shut down, so as to disconnect the power supply and the load, thereby avoiding excessive current flowing through the load, causing damage or even destruction of the load.

[0125] Exemplarily, when the detection voltage is greater than the first reference voltage, the comparison latch circuit 200 may continue to send a shutdown control signal to the switch circuit 100 within a set time period, and stop sending the shutdown control signal after the set time period.

[0126] Alternatively, the comparison latch circuit 200 may continue to send a shutdown control signal to the switch circuit 100 when the detection voltage is greater than the first reference voltage, until the comparison latch circuit 200 receives the conduction control signal and stops sending the shutdown control signal to the switch circuit 100. The conduction control signal may be sent by the control circuit 900, as described later, and will not be described in detail here.

[0127] Based on the above, Figure 2 As shown, in this embodiment, by setting up a current detection circuit 300, the current flowing through the load can be detected, and a detection voltage can be generated based on the current flowing through the load; the comparison latch circuit 200 can obtain the detection voltage and the first reference voltage, and compare the detection voltage and the first reference voltage. When the detection voltage is less than or equal to the first reference voltage, the current flowing through the load is within a set range, the first end and the second end of the switch circuit 100 remain in an on state, and the power supply continues to supply power to the load.

[0128] When the detection voltage is greater than the first reference voltage, the current flowing through the load exceeds the set range. In this case, the comparison latch circuit 200 continuously outputs a shutdown control signal to the switch circuit 100 to control the first end and the second end of the switch circuit 100 to be continuously shut down, thereby avoiding the problem of excessive current flowing through the load causing damage to the load, and ensuring the reliability of power supply between the power supply and the load.

[0129] In some embodiments, Figure 2 As shown, the protection circuit further includes: a reset circuit 500 and a control circuit 900. The first end of the reset circuit 500 is connected to the first end of the comparison latch circuit 200, and the second end of the reset circuit 500 is connected to the control circuit 900. The control circuit 900 is used to send a reset signal to the reset circuit 500. The reset circuit 500 is used to output a reset reference voltage to the first end of the comparison latch circuit 200 under the control of the reset signal, and the reset reference voltage is less than the first reference voltage; the comparison latch circuit 200 is also used to stop outputting the shutdown control signal when receiving the reset reference voltage.

[0130] Exemplarily, the control circuit 900 may be a microcontroller unit (MCU) or other devices with control functions.

[0131] Exemplarily, when the detection voltage is greater than the first reference voltage, the comparison latch circuit 200 may continuously send a shutdown control signal to the switch circuit 100 to continuously disconnect the power supply and the load, until the comparison latch circuit 200 receives a reset reference voltage from the reset circuit 500, and stops sending the shutdown control signal to the switch circuit 100. At this time, the first and second ends of the switch circuit 100 are connected, and the power supply and the load are connected.

[0132] Furthermore, when the detection voltage is greater than the first reference voltage, the current between the switch circuit and the load exceeds the maximum value of the set current range, and there may be an abnormal current fault such as overcurrent or short circuit between the power supply and the load. The control circuit 900 may send a reset signal to the reset circuit 500 after the comparison latch circuit 200 sends a shutdown control signal to the switch circuit 100 for a set period of time, or after the abnormal current fault is resolved, so that the reset circuit 500 outputs a reset reference voltage to the first end of the comparison latch circuit 200 under the control of the reset signal. In this way, the comparison latch circuit 200 stops outputting the shutdown control signal when receiving the reset reference voltage.

[0133] Specifically, in some examples, after the first and second ends of the switch circuit 100 are turned off, the control circuit 900 may be after the comparison latch circuit 200 sends a shutdown control signal to the switch circuit 100 for a set period of time, that is, after the first and second ends of the switch circuit 100 are turned off for a set period of time, and then sends a reset signal to the reset circuit 500 to turn on the first and second ends of the switch circuit 100 again.

[0134] In this way, when the power supply has a transient output abnormality, when the first and second ends of the switch circuit 100 are turned on again after being turned off for a set period of time, there is no current abnormality such as overcurrent between the power supply and the load, and the power supply continues to supply power to the load, avoiding the problem of continuous disconnection between the power supply and the load in the event of a transient fault.

[0135] Furthermore, in the event of an abnormal current fault between the power supply and the load, if the first and second ends of the switch circuit 100 are turned off for a set period of time and then turned on again, there is still an abnormal current fault such as overcurrent between the power supply and the load, and the comparison latch circuit 200 can send a shutdown control signal to the switch circuit 100 and continue for a set period of time; if the comparison latch circuit 200 stops sending the shutdown control signal again, and the first and second ends of the switch circuit 100 are turned off for a set period of time and then turned on again, there is still an abnormal current fault such as overcurrent between the power supply and the load, and the comparison latch circuit 200 can send a shutdown control signal to the switch circuit 100 and continue for a set period of time.

[0136] Based on this, if after m cycles, when the first and second ends of the switch circuit 100 are turned on again after being turned off for a set period of time, there is still an abnormal current fault such as overcurrent between the power supply and the load, the comparison latch circuit 200 may continue to send a shutdown control signal to the switch circuit 100. m is a positive integer greater than or equal to 1, and can be adaptively designed according to actual needs, and the present invention does not limit this.

[0137] Alternatively, in another example, after the first end and the second end of the switching circuit 100 are turned off, the comparison latch circuit 200 may continue to send a shutdown control signal to the switching circuit 100 until the reset reference voltage provided by the reset circuit 500 is received, and the comparison latch circuit 200 stops sending a shutdown control signal to the switching circuit 100.

[0138] In this case, after the first end and the second end of the switch circuit 100 are turned off, the cause of the abnormal current fault may be manually checked and processed. For example, if a power failure is detected, the abnormal current fault is resolved by repairing or replacing the power supply. For another example, if a short circuit is detected between the power supply and the load, the fault is resolved after the short circuit problem is resolved. After the fault is resolved, the control circuit 900 may be manually controlled to send a reset signal. For example, a reset button may be provided on the electronic device, and the control circuit 900 may be controlled to send a reset signal by pressing the reset button.

[0139] In some embodiments, Figure 2 As shown, the control circuit 900 is connected to the fourth terminal Idet_AD of the current detection circuit 300 and the fourth terminal SAF of the switch circuit 100. The current detection circuit 300 is also used to transmit the collected current to the control circuit 900. The control circuit 900 is used to send a control signal to the fourth terminal SAF of the switch circuit 100 when the current is greater than the threshold current, so as to control the first terminal and the second terminal of the switch circuit 100 to be turned off.

[0140] Exemplarily, the control circuit 900 may include a memory, and the threshold current may be stored in the memory.

[0141] The control circuit 900 obtains the current collected by the current detection circuit 300 based on the fourth terminal Idet_AD of the current detection circuit 300. The control circuit 900 compares the current collected by the current detection circuit 300 with the threshold current. When there is an overcurrent or short circuit between the power supply and the load, the current flowing through the load exceeds the threshold current. The control circuit 900 is used to send a control signal to the switch circuit 100 when the current is greater than the threshold current, so as to control the first and second terminals of the switch circuit 100 to be turned off, so as to avoid the problem of load damage caused by abnormal current failure between the power supply and the load.

[0142] In some embodiments, Figure 2 As shown, the protection circuit further includes a first voltage detection circuit 600 and / or a second voltage detection circuit 700 .

[0143] The first end of the first voltage detection circuit 600 is connected to the first end of the switch circuit 100, and the second end U1_AD of the first voltage detection circuit 600 is connected to the control circuit 900; the first voltage detection circuit 600 is used to detect the output voltage of the power supply and transmit the output voltage of the power supply to the control circuit 900. The control circuit 900 is used to control the first end and the second end of the switch circuit 100 to be turned off when the output voltage of the power supply is less than the second reference voltage or greater than the third reference voltage.

[0144] The first end of the second voltage detection circuit 700 is connected to the second end of the switch circuit 100, and the second end U2_AD of the second voltage detection circuit 700 is connected to the control circuit 900; the second voltage detection circuit 700 is used to detect the output voltage of the switch circuit 100, and transmit the output voltage of the switch circuit 100 to the control circuit 900. The control circuit 900 is used to control the first end and the second end of the switch circuit 100 to be turned off when the output voltage is less than the fourth reference voltage or greater than the fifth reference voltage.

[0145] The rated voltage of the power supply is greater than or equal to the second reference voltage and less than or equal to the third reference voltage. The second reference voltage and the third reference voltage can be adaptively designed according to the rated voltage of the power supply and the type of load connected to the power supply, etc., which is not limited in the present disclosure.

[0146] The set output voltage of the control circuit 900 is less than or equal to the fourth reference voltage and greater than or equal to the fifth reference voltage. The fourth reference voltage and the fifth reference voltage can be adaptively designed according to the rated voltage of the power supply terminal, the type of load connected to the power supply, and the specific structure of the switch circuit 100, and the present disclosure does not limit this.

[0147] When the power supply has an abnormal voltage fault (power supply undervoltage or overvoltage), the power supply continuing to supply power to the load may cause damage to the power supply or the load. By setting the first voltage detection circuit 600, the output voltage of the power supply can be detected in real time, and the control circuit 900 can obtain the output voltage of the power supply detected by the first voltage detection circuit 600 in real time. When the power supply has an abnormal voltage fault, the first end and the second end of the control switch circuit 100 are disconnected to avoid damage to the power supply or the load due to the abnormal output voltage of the power supply.

[0148] The control circuit 900 can detect the output voltage of the switch circuit 100 in real time through the second voltage detection circuit 700, so as to determine whether there is an abnormality in the switch circuit 100. For example, when the first end and the second end of the switch circuit 100 are conductive, if the detection voltage of the second voltage detection circuit 700 is 0V, there is a conductive abnormality between the first end and the second end of the switch circuit 100.

[0149] Furthermore, the voltage output from the switch circuit 100 to the load can be detected in real time through the second voltage detection circuit 700. When the voltage output from the switch circuit 100 to the load is less than the fourth reference voltage or greater than the fifth reference voltage, the output voltage of the switch circuit 100 is undervoltage or overvoltage, and the power supply continuing to supply power to the load may cause damage to the power supply or the load. The control circuit 900 can obtain the output voltage of the switch circuit 100 detected by the second voltage detection circuit 700 in real time. When the switch circuit 100 has an abnormal voltage fault, the first end and the second end of the switch circuit 100 are controlled to be disconnected to avoid damage to the load caused by the abnormal output voltage of the switch circuit 100.

[0150] Based on the above, take the rated current of the load as I2, the minimum current allowed to flow through the load under normal operation as I1, and the maximum current allowed to flow through the load as I3 as an example (when the current flowing through the load is less than I2 or greater than I3, the load is at risk of damage).

[0151] When the current between the switch circuit 100 and the load is within the first preset current range (I1, I2), the current between the switch circuit 100 and the load is less than the rated current of the load, but can still support the normal operation of the load; when the current between the switch circuit 100 and the load is within the third preset current range (I2, I3), the current between the switch circuit 100 and the load is greater than the rated current of the load, but can still support the normal operation of the load.

[0152] The current detection circuit 300 detects the current flowing through the load and converts it into a corresponding analog voltage signal (the detection voltage generated by the current detection circuit according to the current), and outputs the analog voltage signal to the control circuit 900 through the fourth terminal Idet_AD of the current detection circuit 300. The control circuit 900 can continuously detect the current between the switch circuit 100 and the load, and determine whether to turn off the switch circuit 100 based on whether the detection result exceeds the normal value.

[0153] Specifically, the current detection circuit 300 can collect the current between the switch circuit 100 and the load, and generate a detection voltage according to the current, and output the detection voltage, and the detection voltage is used to characterize the current between the switch circuit 100 and the load. The control circuit 900 can collect the current between the switch circuit 100 and the load in real time through the current detection circuit 300. The control circuit 900 can collect the detection voltage output by the current detection circuit 300 in real time, and obtain the current between the switch circuit 100 and the load according to the detection voltage.

[0154] When the current between the switch circuit 100 and the load is within the first preset current range (I1, I2) or within the third preset current range (I2, I3), the current between the switch circuit 100 and the load is less than or greater than the rated current of the load but does not exceed the minimum current or maximum current allowed for normal operation of the load, the control circuit 900 can determine whether there is an abnormal current fault between the switch circuit 100 and the load based on the current between the switch circuit 100 and the load detected in real time.

[0155] For example, the current between the switch circuit 100 and the load continues to be large (the current between the switch circuit 100 and the load continues to remain close to I3, or the current between the switch circuit 100 and the load exceeds I3); or, the current between the switch circuit 100 and the load continues to increase; or, the current between the switch circuit 100 and the load continues to fluctuate (for example, the current between the switch circuit 100 and the load repeatedly changes between close to I3 and close to I1).

[0156] The control circuit 900 determines that there is an abnormal current fault between the switch circuit 100 and the load based on the above different situations. The control circuit 900 may issue different warning signals according to the above different abnormal current situations.

[0157] Furthermore, while issuing a warning signal, the control circuit 900 can also issue a control signal to the switch circuit 100 to control the first and second ends of the switch circuit 100 to be turned off, so as to disconnect the power supply and the load, thereby protecting the load and preventing the load from being damaged when the current between the switch circuit 100 and the load is abnormal.

[0158] The control circuit 900 controls the first and second ends of the switch circuit 100 to be turned off based on the current between the switch circuit 100 and the load obtained by the current detection circuit 300, which is not limited to the above, and can also control the first and second ends of the switch circuit 100 to be turned off when the detection current is greater than the threshold current. This disclosure does not limit this.

[0159] For example, the control circuit 900 can send normal or fault information to the outside through an indicator light and / or a network. The indicator light can be displayed in different colors to indicate that the circuit is working normally or has a fault. At the same time, the indicator light can be displayed in different colors to indicate that different parts of the circuit have a fault. The network includes at least one of CAN, LIN, Ethernet, etc.

[0160] In some other embodiments, Figure 2 As shown, in the case where the protection circuit includes a first voltage detection circuit 600 and a second voltage detection circuit 700, the control circuit 900 is also used to control the first end and the second end of the switch circuit 100 to be turned off when the difference between the output voltage of the power supply and the output voltage of the switch circuit 100 meets a predetermined condition.

[0161] The control circuit 900 can detect the output voltage of the power supply and the output voltage of the switching circuit 100 in real time through the first voltage detection circuit 600 and the second voltage detection circuit 700. Even if one of the first voltage detection circuit 600 and the second voltage detection circuit 700 fails, the voltage output to the load can still be detected in real time through the other one. By setting the first voltage detection circuit 600 and the second voltage detection circuit 700, the reliability of voltage detection can be guaranteed.

[0162] Furthermore, when there is no fault in the switching circuit 100, the voltage difference between the first end and the second end of the switching circuit 100 is within a certain range, for example, a set range (U1, U2), and the voltage difference between the first end and the second end of the switching circuit 100 can be detected by the first voltage detection circuit 600 and the second voltage detection circuit 700. When the voltage difference between the first end and the second end of the switching circuit 100 is greater than or equal to U2, or less than or equal to U1, the control circuit 900 determines that there is a fault in the switching circuit 100, and controls the first end and the second end of the switching circuit 100 to be turned off, so as to avoid damage to the power supply and / or load due to the fault of the switching circuit 100.

[0163] Based on the above embodiments, in the protection circuit provided by some embodiments of the present invention, by setting a first voltage detection circuit 600 and a second voltage detection circuit 700, when there is an abnormal voltage fault (such as undervoltage or overvoltage) between the power supply and the load, the control circuit 900 can issue a voltage abnormality fault warning based on the detected undervoltage or overvoltage information.

[0164] For example, the preset voltage range (1), the preset voltage range (2), ..., the preset voltage range (n) may be divided according to actual needs, where n is a positive integer greater than or equal to 2. When the difference between the detection voltage and the set voltage is within different preset ranges, the control circuit 600 sends different warning signals, which are used to characterize the degree of deviation between the detection voltage and the set voltage, and the preset voltage range (1) to the preset voltage range (n) gradually increases.

[0165] That is, when the difference between the detection voltage and the set voltage is within the preset voltage range (n), compared with when the difference between the detection voltage and the set voltage is within the preset voltage range (1), the greater the deviation between the detection voltage and the preset voltage, the greater the possibility that the power supply or load is damaged.

[0166] Specifically, when the difference between the detection voltage and the set voltage is within the preset voltage range (1) to the preset voltage range (n-1), the control circuit 900 may only issue a warning signal to warn that there is an abnormal voltage fault between the power supply and the load.

[0167] Furthermore, when the difference between the detection voltage and the set voltage is within the preset voltage range (n) or exceeds the preset voltage range (n), the control circuit 900 sends a warning signal and also sends a control signal to the switch circuit 100 to control the first end and the second end of the switch circuit (100) to be turned off, thereby protecting the load.

[0168] Based on the foregoing, the control circuit 900 can detect the output voltage of the power supply in real time through the first voltage detection circuit 600, and can detect the output voltage of the switching circuit 100 in real time through the second voltage detection circuit 700. The detection value of the first voltage detection circuit 600 and the detection value of the second voltage detection circuit 700 can be used to determine whether the power supply is under-voltage or over-voltage. The control circuit 900 can also determine whether the first end and the second end of the switching circuit 100 are normally turned on or off based on the power difference between the first voltage detection circuit 600 and the second voltage detection circuit 700, thereby improving the reliability of the protection circuit.

[0169] Based on the above embodiments, in some embodiments, such as Figure 2 As shown, the third terminal KW of the first voltage detection circuit 600 is connected to the control circuit 900. The control circuit 900 is used to transmit a detection control signal to the third terminal KW of the first voltage detection circuit 600 when the first terminal and the second terminal of the switch circuit 100 are turned on, so as to control the first terminal of the first voltage detection circuit 600 to be turned on with the first terminal of the switch circuit 100.

[0170] After the electronic device is powered on (i.e., when the first end and the second end of the switch circuit 100 change from an off state to an on state), the control circuit 900 transmits a detection control signal to the third end KW of the first voltage detection circuit 600, controls the first end of the first voltage detection circuit 600 to be conductive with the first end of the switch circuit 100, and the first voltage detection circuit 600 detects the output voltage of the power supply.

[0171] When the electronic device is in sleep mode, the first end of the first power detection circuit 600 is disconnected from the first end of the switch circuit 100, and the first voltage detection circuit 600 does not work, which can reduce the power consumption of the protection circuit when the electronic device is in sleep mode.

[0172] In some embodiments, Figure 2 As shown, the protection circuit further includes a reference circuit 400 connected to the third terminal of the comparison latch circuit 200. The reference circuit 400 is used to output a first reference voltage to the comparison latch circuit.

[0173] Exemplarily, the reference circuit 400 is connected to the power signal terminal VCC and the ground terminal, and the reference circuit 400 generates and outputs a first reference voltage according to the power signal provided by the power signal terminal VCC and the ground signal provided by the ground terminal. The first reference voltage provided by the reference circuit 400 is independent of the type of power supply, so that the protection circuit can be applied between various types of power supplies and loads, which expands the application scenarios of the protection circuit and improves the adaptability of the protection circuit.

[0174] In some embodiments, Figure 2 As shown, the protection circuit also includes an anti-reverse circuit 800 connected between the power supply and the switch circuit 100, and used to control the current to flow unidirectionally from the power supply to the switch circuit 100.

[0175] The anti-reverse circuit 800 is connected between the power supply and the load, and can ensure that the current between the power supply and the load only flows from the power supply to the load. Exemplarily, the anti-reverse circuit 800 can be a diode, or a device with an anti-reverse connection function such as a MOS.

[0176] For example, the anti-reverse circuit 800 may include a ninth switch element Q9. Figure 4 As shown, the control electrode and the first electrode of the ninth switch element Q9 are both connected to the power supply, and the second electrode of the ninth switch element Q9 is connected to the first end of the switch circuit 100 .

[0177] The anti-reverse circuit 800 may include a fourth diode, a first electrode of the fourth diode is connected to the power supply, and a second electrode of the fourth diode is connected to the first end of the switch circuit 100 .

[0178] Based on the foregoing embodiments, in some embodiments, such as Figure 3As shown, the switch circuit includes: a switch subcircuit 110 and a driving subcircuit 120. The first end of the switch subcircuit 110 is connected to the first end of the switch circuit 100, and the second end of the switch subcircuit 110 is connected to the second end of the switch circuit 100. The first end of the driving subcircuit 120 is connected to the third end of the switch circuit 100, and the second end of the driving subcircuit 120 is connected to the fourth end SAF of the switch circuit 100. The third end of the switch subcircuit 110 is connected to the third end of the driving subcircuit 120. The driving subcircuit 120 is used to control the switch subcircuit 110 to turn off the first end and the second end of the switch circuit 100 based on the turn-off control signal.

[0179] When the power supply is powered on, the control circuit 900 can drive the switch subcircuit 110 to open through the second terminal SAF of the driving subcircuit 120 in the switch circuit 100 (the fourth terminal SAF of the switch circuit 100 ), and the power supply supplies power to the load through the switch subcircuit 110 .

[0180] The specific circuit structures of the protection circuits of some embodiments of the present invention are introduced below.

[0181] In some embodiments, Figure 3 and Figure 4 As shown, the switch subcircuit 110 includes a first switch element Q1, a control electrode of the first switch element Q1 is connected to the third end of the switch subcircuit 110, a first electrode of the first switch element Q1 is connected to the first end of the switch subcircuit 110, and a second electrode of the first switch element Q1 is connected to the second end of the switch subcircuit 110.

[0182] For example, Figure 3 and Figure 4 As shown, the first electrode of the first switch element Q1 is connected to the anti-reverse circuit 800, and the second electrode of the first switch element Q1 is connected to the first end of the second voltage detection circuit 700 and the first end of the current detection circuit 300. When the first switch element Q1 is in the on state, the power supply and the load are connected; when the first switch element Q1 is in the off state, the power supply and the load are disconnected. The first switch element Q1 is used to control the on and off between the power supply and the load.

[0183] Exemplarily, the first switch element Q1 may be a device having a switching function, such as a transistor, a MOS transistor, an IGBT, or a relay.

[0184] In some embodiments, Figure 3 and Figure 4 As shown, the switch sub-circuit 110 further includes: at least one of a first diode D1 , a first resistor R1 , and a first capacitor C1 .

[0185] Exemplarily, the first diode D1 is a voltage-stabilizing diode, a first electrode of the first diode D1 is connected to a control electrode of the first switch element Q1, and a second electrode of the first diode D1 is connected to a first electrode of the first switch element Q1.

[0186] Under transient voltage shocks such as electrostatic discharge, the first diode D1 connected in parallel to the control electrode and the first electrode of the first switching element Q1 can be quickly turned on and absorb excess charge, thereby preventing the first switching element Q1 from being damaged. At the same time, the first diode D1 can also effectively prevent the control electrode voltage of the first switching element Q1 from being too high, thereby preventing the voltage spike from damaging the first switching element Q1.

[0187] Exemplarily, a first end of the first resistor R1 is connected to a control electrode of the first switch element Q1 , and a second end of the first resistor R1 is connected to a first electrode of the first switch element Q1 .

[0188] The first resistor R1 is connected in parallel to the control electrode and the first electrode of the first switch element Q1 , which can increase the resistance between the control electrode and the first electrode of the first switch element Q1 and prevent the first switch element Q1 from oscillating.

[0189] Exemplarily, a first end of the first capacitor C1 is connected to a control electrode of the first switch element Q1 , and a second end of the first capacitor C1 is connected to a first electrode of the first switch element Q1 .

[0190] The second capacitor C2 is connected in parallel to the control electrode and the first electrode of the first switch element Q1, and is used to mitigate the damage to the first switch element Q1 caused by switching shocks such as transient overvoltage and transient overcurrent due to rapid changes in voltage and current when the first switch element Q1 is turned on or off.

[0191] In some embodiments, Figure 3 As shown, the switch sub-circuit 110 further includes: a second resistor R2, a second switch element Q2 and a second diode D2.

[0192] Exemplarily, the second switch element Q2 may be a device having a switch function, such as a triode, a MOS tube, an IGBT, a relay, etc. The control electrode of the second switch element Q2 is connected to the third end of the switch subcircuit 110, the first electrode of the second switch element Q2 is connected to the first end of the switch subcircuit 110, and the second electrode of the second switch element Q2 is connected to the control electrode of the first switch element Q1.

[0193] A first end of the second resistor R2 is connected to a first end of the switch sub-circuit 110 , and a second end of the second resistor R2 is connected to a control electrode of the second switch element Q2 .

[0194] A first end of the second diode D2 is connected to the second electrode of the second switch element Q2 , and a second end of the second diode D2 is connected to the control electrode of the first switch element Q1 .

[0195] The second resistor R2, the second switch element Q2 and the third diode D3 form a fast charge and discharge loop, which can quickly charge and discharge when the first switch element Q1 is turned on or off, thereby shortening the on or off time of the first switch element Q1.

[0196] In some embodiments, Figure 3 As shown, the driving sub-circuit 120 includes: a third switch element Q3 and a fourth switch element Q4. The control electrode of the third switch element Q3 is connected to the second end of the driving sub-circuit 120, the first electrode of the third switch element Q3 is connected to the third end of the driving sub-circuit 120, and the second electrode of the third switch element Q3 is connected to the ground end. The control electrode of the fourth switch element Q4 is connected to the first end of the driving sub-circuit 120, the first electrode of the fourth switch element Q4 is connected to the control electrode of the third switch element Q3, and the second electrode of the fourth switch element Q4 is connected to the ground end.

[0197] The third switch element Q3 is used to turn on or off the first switch element Q1. The fourth switch element Q4 is used to turn on or off the third switch element Q3.

[0198] Exemplarily, the third switch element Q3 and the fourth switch element Q4 may be devices with a switching function, such as a transistor, a MOS transistor, an IGBT, or a relay.

[0199] For example, Figure 3 and Figure 4 As shown, the current detection circuit 300 is used to detect the current flowing through the load, and convert it into a corresponding analog voltage signal (the detection voltage generated by the current detection circuit according to the current), and output the detection voltage to the comparison latch circuit 200. If the detection voltage is lower than the first reference voltage provided by the reference circuit 400, the signal output from the second end of the comparison latch circuit 200 cannot turn on the fourth switch element Q4 of the drive sub-circuit 120. In this case, the third switch element Q3 can be driven to work by the switch circuit 100 under the control of the control circuit 900.

[0200] In the protection circuit, when the current between the switch circuit 100 and the load exceeds the threshold current, the control circuit 900 can transmit a shutdown control signal through the fourth terminal SAF of the switch circuit 100 to turn off the third switch element Q3, thereby quickly turning off the first switch element Q1 of the switch sub-circuit 110 to disconnect the first end and the second end of the switch circuit 100 to avoid load damage due to overcurrent or short circuit.

[0201] In some embodiments, Figure 3 and Figure 4 As shown, the driving sub-circuit 120 further includes: a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the control electrode of the third switch element Q3, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected to the ground end. The common terminal SAF of the third resistor R3 and the fourth resistor R4 is the second end of the driving sub-circuit 120.

[0202] like Figure 4 As shown, the third resistor R3 is connected between the control electrode of the third switch element Q3 and the second end of the driving sub-circuit 120 . When the control circuit 900 transmits a control signal to the second end of the driving sub-circuit 120 , the third resistor R3 can play a current limiting role.

[0203] When the electronic device is cold started (disconnecting the power supply and the load, and reconnecting the power supply and the load), the control circuit 900 does not transmit a control signal to the second end of the driving sub-circuit 120, and transmits a ground signal to the second end of the driving sub-circuit 120 through the fourth resistor R4 to lower the potential of the fourth end SAF of the switching circuit 100.

[0204] The third resistor R3 and the fourth resistor R4 work together to prevent the third switch element Q3 from oscillating.

[0205] In some embodiments, Figure 3 and Figure 4 As shown, the driving sub-circuit 120 also includes: a fifth resistor R5 and a sixth resistor R6. The first end of the fifth resistor R5 is connected to the control electrode of the third switch element Q3, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, and the second end of the sixth resistor R6 is connected to the ground end. The common terminal of the fifth resistor R5 and the sixth resistor R6 is the fifth terminal DIA_AD of the switch circuit 100, and the fifth terminal DIA_AD of the switch circuit 100 is connected to the control circuit 900. The fifth terminal DIA_AD of the switch circuit 100 is used to output a feedback signal to the control circuit 900, and the feedback signal is used to characterize the conduction state of the fourth switch element Q4.

[0206] The fifth resistor R5 and the sixth resistor R6 are connected in series between the first electrode and the ground terminal of the fourth switch element Q4. The fifth resistor R5 and the sixth resistor R6 are used for voltage division. The divided voltage is output to the control circuit 900 through the fifth terminal DIA_AD of the switch circuit 100. The control circuit 900 can determine the output terminal state of the fourth switch element Q4 based on the voltage.

[0207] The control circuit 900 can determine whether the switch circuit 100 has a fault through the states of the fourth terminal SAF of the switch circuit 100 and the fifth terminal DIA_AD of the switch circuit 100 and the detection value of the current detection circuit 300, the detection value of the first voltage detection circuit 600 and the detection value of the second voltage detection circuit 700.

[0208] For example, when the current detection circuit 300 detects that the current between the switch circuit 100 and the load exceeds the threshold current, the comparison latch circuit 200 outputs a shutdown control signal to the fourth switch element Q4 to shut down the first switch element Q1 through the third switch element Q3. The control circuit 900 obtains the feedback signal output from the fifth terminal DIA_AD of the switch circuit 100 to determine the state of the fourth switch element Q4, thereby determining whether the comparison latch circuit 200 outputs a shutdown control signal to the fourth switch element Q4.

[0209] In some embodiments, Figure 3 He Ru Figure 4 As shown, the driving sub-circuit 120 further includes a nineteenth resistor R19 , a first end of the nineteenth resistor R19 is connected to the second electrode of the third switch element Q3 , and a second end of the nineteenth resistor R19 is connected to the third end of the switch sub-circuit 110 .

[0210] The nineteenth resistor R19 is connected between the control electrode of the first switch element Q1 and the second electrode of the third switch element Q3, and can play a current limiting role.

[0211] In some embodiments, Figure 3 He Ru Figure 4 As shown, the driving sub-circuit 120 further includes a fifth capacitor C5, a first end of the fifth capacitor C5 is connected to the control electrode of the third switch element Q3, and a second end of the fifth capacitor C5 is connected to the ground end.

[0212] The fifth capacitor C5 is connected between the control electrode and the second electrode of the third switch element Q3 to play a filtering role.

[0213] In some embodiments, Figure 3 He Ru Figure 4 As shown, the driving subcircuit 120 further includes a twentieth capacitor R20, a first end of which is connected to the control electrode of the fourth switch element Q4, and a second end of which is connected to the ground terminal. The twentieth capacitor R20 is used to prevent the fourth switch element Q4 from oscillating.

[0214] In some embodiments, Figure 3 He Ru Figure 4As shown, the driving sub-circuit 120 also includes a twenty-first resistor R21 , a first end of the twenty-first resistor R21 is connected to the control terminal of the fourth switch element Q4 , and a second end of the twenty-first resistor R21 is connected to the second end of the comparison latch circuit 200 .

[0215] The twenty-first resistor R21 is used for current limiting to prevent excessive current flowing to the fourth switch element Q4 from damaging the fourth switch element Q4.

[0216] In some embodiments, Figure 3 and Figure 5 As shown, the comparison latch circuit 200 includes: a first chip U1, a seventh resistor R7 and a third diode D3. The first input terminal of the first chip U1 is connected to the first terminal of the comparison latch circuit 200, the second input terminal of the first chip U1 is connected to the third terminal of the comparison latch circuit 200, and the output terminal of the first chip U1 is connected to the second terminal of the switch circuit 100. The first terminal of the seventh resistor R7 is connected to the output terminal of the first chip U1, the second terminal of the seventh resistor R7 is connected to the first terminal of the third diode D3, and the second terminal of the third diode D3 is connected to the first input terminal of the first chip U1.

[0217] The first end of the seventh resistor R7 is connected to the output end of the first chip U1, and the second end of the seventh resistor R7 is connected to the positive end of the third diode D3, which plays a current limiting role to prevent excessive current from flowing from the output end of the first chip U1 to the first input end of the first chip U1 and causing damage to the first chip U1.

[0218] Exemplarily, the first chip U1 includes a comparator.

[0219] In some examples, such as Figure 5 As shown, the second input terminal of the first chip U1 is connected to the output terminal of the reference circuit 400, and the input signal (detection voltage) of the first input terminal of the first chip U1 is compared with the input signal (first reference voltage) of the second input terminal. If the detection voltage is higher than the first reference voltage, a high level (shutdown control signal) is output to control the fourth switch element Q4 to turn on; if the detection voltage is lower than the first reference voltage, a low level is output to control the fourth switch element Q4 to turn off.

[0220] like Figure 3 As shown, when the fourth switch element Q4 is turned on, the ground signal provided by the ground terminal is transmitted to the control electrode of the third switch element Q3 through the fourth switch element Q4 to turn off the third switch element Q3, and then quickly turn off the first switch element Q1 of the switch sub-circuit 110, which can avoid the situation where the control circuit 900 does not respond in time and the first and second ends of the switch circuit 100 cannot be disconnected in time, thereby improving the reliability of the protection circuit.

[0221] The first chip U1, the seventh resistor R7 and the third diode D3 form a feedback circuit, which can lock the signal in the fault state. In this way, when the comparison result of the input signal (detection voltage) of the first input terminal of the first chip U1 and the input signal (first reference voltage) of the second input terminal is to output the shutdown control signal, even if the detection voltage from the current detection circuit 300 changes (for example, the detection voltage becomes the first reference voltage), the first chip U1 can continue to output the shutdown control signal.

[0222] The positive end of the third diode D3 is connected to the seventh resistor R7, and the negative end of the third diode D3 is connected to the first input end of the first chip U1, which can prevent the change of the input signal of the first input end of the first chip U1 from affecting the output of the first chip U1. The seventh resistor R7 and the third diode D3 jointly transmit the output of the first chip U1 to the first input end of the first chip U1 when a fault occurs, so that the voltage of the first input end of the first chip U1 is higher than the first reference voltage provided by the reference circuit 400, thereby locking the abnormal current fault state.

[0223] In some embodiments, Figure 3 and Figure 5 As shown, the comparison latch circuit 200 also includes a fifth switch element Q5, the control electrode of the fifth switch element Q5 is connected to the output end of the first chip U1, the first electrode of the fifth switch element Q5 is connected to the power signal end VCC, and the second electrode of the fifth switch element Q5 is connected to the second end of the comparison latch circuit 200.

[0224] Exemplarily, the fifth switch element Q5 may be a device having a switching function, such as a transistor, a MOS transistor, an IGBT, or a relay.

[0225] The fifth switch element Q5 can be provided to amplify and drive the output signal of the first chip U1, so as to ensure that the shutdown control signal output by the comparison latch circuit 200 can effectively drive the first end and the second end of the switch circuit 100 to shut down.

[0226] In the case where the driving capability of the first chip U1 is sufficient, the fifth switch element Q5 may not be provided. The adaptive design may be performed according to actual needs, and the present disclosure does not limit this.

[0227] In some embodiments, Figure 3 and Figure 5 As shown, the first power terminal of the first chip U1 is connected to the power signal terminal VCC, and the second power terminal of the first chip U1 is connected to the ground terminal.

[0228] The comparison latch circuit 200 further includes a twenty-second resistor R22 and / or a fifth capacitor C5. A first end of the twenty-second resistor R22 is connected to the first power supply terminal of the first chip U1, and a second end of the twenty-second resistor R22 is connected to the output terminal of the first chip U1. A first end of the fifth capacitor C5 is connected to the first power supply terminal of the first chip U1, and a second end of the fifth capacitor C5 is connected to the ground terminal.

[0229] The fifth capacitor C5 plays a filtering role, and the twenty-second resistor R22 plays a pull-up role. The power signal terminal VCC can be a power supply connected to a voltage conversion circuit for step-down and then supplying power, or it can be another power signal terminal independent of the power supply. The power provided by the power signal terminal VCC can be 5V or 3.3V, or other values, and can be adaptively designed according to needs.

[0230] In some embodiments, Figure 3 and Figure 6 As shown, the current detection circuit 300 includes: a second chip U2 and an eighth resistor R8. The first end of the eighth resistor R8 is connected to the first end of the current detection circuit 300, and the second end of the eighth resistor R8 is connected to the second end of the current detection circuit 300. The first input end of the second chip U2 is connected to the first end of the eighth resistor R8, the second input end of the second chip U2 is connected to the second end of the eighth resistor R8, and the output end of the second chip U2 is connected to the third end of the current detection circuit 300.

[0231] Exemplarily, the second chip U2 may be an amplifier.

[0232] The eighth resistor R8 is used to convert the current signal into a voltage signal. The second chip U2 appropriately amplifies the voltage across the eighth resistor R8 and then outputs a corresponding linear voltage (detection voltage).

[0233] In some embodiments, Figure 3 and Figure 6 As shown, the current detection circuit 300 also includes: a twenty-third resistor R23 and a twenty-fourth resistor R24. The first end of the twenty-third resistor R23 is connected to the first end of the eighth resistor R8, and the second end of the twenty-third resistor R23 is connected to the first input end of the second chip U2. The first end of the twenty-fourth resistor R24 ​​is connected to the first end of the eighth resistor R8, and the second end of the twenty-fourth resistor R24 ​​is connected to the second input end of the second chip U2.

[0234] The twenty-third resistor R23 and the twenty-fourth resistor R24 ​​play a role of current limiting protection. The second chip U2 detects the voltage across the eighth resistor R8 through the twenty-third resistor R23 and the twenty-fourth resistor R24, and outputs a corresponding linear voltage after appropriate amplification.

[0235] In some embodiments, Figure 3 and Figure 6 As shown, the current detection circuit 300 further includes: a sixth capacitor C6, a first end of the sixth capacitor C6 is connected to the first end of the current detection circuit 300, and a second end of the sixth capacitor C6 is connected to the second end of the current detection circuit 300. The sixth capacitor C6 plays a filtering role.

[0236] In some embodiments, Figure 3 and Figure 6 As shown, the current detection circuit 300 further includes: a twenty-fifth resistor R25 and a seventh capacitor C7.

[0237] The first end of the twenty-fifth resistor R25 is connected to the output end of the second chip U2, the second end of the twenty-fifth resistor R25 is connected to the first end of the seventh capacitor C7, and the second end of the seventh capacitor C7 is connected to the ground end. The common end of the twenty-fifth resistor R25 and the seventh capacitor C7 is the fourth end Idet_AD of the current detection circuit 300.

[0238] One end of the twenty-fifth resistor R25 is connected to the output end of the second chip U2 to limit the current. The twenty-fifth resistor R25 and the seventh capacitor C7 form a low-pass filter circuit to improve the reliability of the signal output to the control circuit 900 through the fourth end Idet_AD of the current detection circuit 300.

[0239] In some embodiments, Figure 3 and Figure 6 As shown, the twenty-sixth resistor R26 and the eighth capacitor C8. The first end of the twenty-sixth resistor R26 is connected to the output end of the second chip U2, and the second end of the twenty-sixth resistor R26 is connected to the first end of the comparison latch circuit 200. The first end of the eighth capacitor C8 is connected to the first end of the comparison latch circuit 200, and the second end of the eighth capacitor C8 is connected to the ground end.

[0240] One end of the twenty-sixth resistor R26 is connected to the output end of the second chip U2 and one end of the twenty-fifth resistor R25, which plays a current limiting role. The twenty-sixth resistor R26 and the eighth capacitor C8 together form a low-pass filter circuit, and the output voltage signal is transmitted to the first end of the comparison latch circuit 200, thereby improving the reliability of the output signal of the current detection circuit 300.

[0241] In some embodiments, Figure 3 and Figure 7As shown, the reference circuit 400 includes: a seventeenth resistor R17 and an eighteenth resistor R18. The first end of the seventeenth resistor R17 is connected to the ground terminal, the second end of the seventeenth resistor R17 is connected to the first end of the eighteenth resistor R18, and the second end of the eighteenth resistor R18 is connected to the power signal terminal VCC. The common terminal REF of the seventeenth resistor R17 and the eighteenth resistor R18 is connected to the third end of the comparison latch circuit 200.

[0242] The seventeenth resistor R17 and the eighteenth resistor R18 are connected in series between the power signal terminal VCC and the ground terminal. The seventeenth resistor R17 and the eighteenth resistor R18 are used for voltage division. The common terminal REF of the seventeenth resistor R17 and the eighteenth resistor R18 is used to provide a first reference voltage to the comparison latch circuit 200.

[0243] The first reference voltage can be designed to match the threshold current, and the first reference voltage output by the reference circuit 400 can be changed by changing the ratio of the resistance values ​​of the seventeenth resistor R17 and the eighteenth resistor R18.

[0244] In this way, the reference circuit 400 has a simple structure and can be applied to various power supply types, thereby improving the adaptability of the protection circuit.

[0245] In some embodiments, Figure 3 and Figure 8 As shown, the reset circuit 500 includes: a sixth switch element Q6, a ninth resistor R9 and a tenth resistor R10. The first end of the ninth resistor R9 is connected to the ground end, the second end of the ninth resistor R9 is connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is connected to the control electrode of the sixth switch element Q6, the first electrode of the sixth switch element Q6 is connected to the first end of the reset circuit 500, and the second electrode of the sixth switch element Q6 is connected to the ground end. The common terminal of the ninth resistor R9 and the tenth resistor R10 is the second terminal REST of the reset circuit 500.

[0246] When the abnormal current fault is relieved, or the abnormal current fault is instantaneous, without power failure, the control circuit 900 controls the sixth switch element Q6 to be turned on through the second end REST of the reset circuit 500, and pulls down the voltage of the first input end of the comparison latch circuit 200 to make it lower than the first reference voltage provided by the reference circuit 400, thereby releasing the fault locking state of the comparison latch circuit 200, and allowing the comparison latch circuit 200 to continue to determine whether there is an overcurrent or short circuit state based on the detection voltage provided by the current detection circuit 300 and the first reference voltage provided by the reference circuit 400.

[0247] The sixth switch element Q6 functions as a switch, and can pull down the potential of the first input terminal of the comparison latch circuit 200 , thereby resetting the comparison latch circuit 200 and releasing the fault latch state of the comparison latch circuit 200 .

[0248] The tenth resistor R10 is connected between the control electrode of the sixth switch element Q6 and the second end REST of the reset circuit 500, and plays a current limiting role. It can prevent the control electrode of the sixth switch element Q6 from being damaged by excessive current flowing through the control electrode of the sixth switch element Q6 when the control circuit 900 outputs a reset signal to the sixth switch element Q6 through the second end REST of the reset circuit 500.

[0249] The ninth resistor R9 is connected between the second end REST of the reset circuit 500 and the ground end. When the electronic device is cold started, the control circuit 900 does not output an electrical signal to the reset circuit 500. The second end REST of the reset circuit 500 is connected to the ground end through the ninth resistor R9, so that the second end REST of the reset circuit 500 is at a low level, thereby preventing the second end REST of the reset circuit 500 from accidentally outputting a high-level signal, causing the comparison latch circuit 200 to have a fault latching problem in the absence of an abnormal current fault.

[0250] The ninth resistor R9 and the tenth resistor R10 can also prevent the sixth switch element Q6 from oscillating.

[0251] In some embodiments, Figure 3 and Fig. 9 As shown, the first voltage detection circuit 600 includes: an eleventh resistor R11, a twelfth resistor R12 and a second capacitor C2. The first end of the eleventh resistor R11 is connected to the first end of the first voltage detection circuit 600, the second end of the eleventh resistor R11 is connected to the first end of the twelfth resistor R12, and the second end of the twelfth resistor R12 is connected to the ground. The common end of the eleventh resistor R11 and the twelfth resistor R12 is the second end U1_AD of the first voltage detection circuit 600. The first end of the second capacitor C2 is connected to the second end U1_AD of the first voltage detection circuit 600, and the second end of the second capacitor C2 is connected to the ground.

[0252] The eleventh resistor R11 and the twelfth resistor R12 play a role of voltage division, and the divided voltage is output to the control circuit 900 through the second terminal U1_AD of the first voltage detection circuit 600. The second capacitor C2 is connected in parallel with the twelfth resistor R12 to play a filtering role.

[0253] In some embodiments, Figure 3 and Fig. 9As shown, the first voltage detection circuit 600 also includes: a seventh switch element Q7, an eighth switch element Q8, a thirteenth resistor R13 and a fourteenth resistor R14. The first end of the thirteenth resistor R13 is connected to the third end KW of the first voltage detection circuit 600, the second end of the thirteenth resistor R13 is connected to the first end of the fourteenth resistor R14, and the second end of the fourteenth resistor R14 is connected to the ground end. The common end of the thirteenth resistor R13 and the fourteenth resistor R14 is connected to the control electrode of the eighth switch element Q8, the first electrode of the eighth switch element Q8 is connected to the control electrode of the seventh switch element Q7, and the second electrode of the eighth switch element Q8 is connected to the ground end. The first electrode of the seventh switch element Q7 is connected to the first end of the first voltage detection circuit 600, and the second electrode of the seventh switch element Q7 is connected to the first end of the eleventh resistor R11.

[0254] The seventh switch element Q7, the eighth switch element Q8, the thirteenth resistor R13 and the fourteenth resistor R14 serve as switch units of the first voltage detection circuit 600, ensuring that when the electronic device is in a sleep state, the connection between the first voltage detection circuit 600 and the first end of the switch circuit 100 is disconnected, thereby reducing the power consumption of the protection circuit.

[0255] When the electronic device is in a dormant state or just powered on, the control circuit 900 does not send a control signal to the third terminal KW of the first voltage detection circuit 600, and the control electrode of the eighth switch element Q8 is connected to the ground terminal through the fourteenth resistor R14, so that the eighth switch element Q8 can be guaranteed to be closed when the electronic device is in a dormant state or just powered on, so that the seventh switch element Q7 can be closed, so that when the electronic device is in a dormant state or just powered on, the first voltage detection circuit 600 is disconnected from the first end of the switch circuit 100. The first voltage detection circuit 600 does not generate additional power consumption when the electronic device is in a dormant state.

[0256] After the electronic device is powered on, the control circuit 900 opens the seventh switch element Q7 through the third terminal KW of the first voltage detection circuit 600, the first terminal of the first voltage detection circuit 600 is connected to the first terminal of the switch circuit 100, and the first voltage detection circuit 600 starts to detect the output voltage of the power supply.

[0257] In some embodiments, Figure 3 and Fig. 9 As shown, the first end of the twenty-seventh resistor R27 is connected to the control electrode of the seventh switch element Q7, the first electrode of the seventh switch element Q7 is connected to the first end of the switch circuit 100, and the second electrode of the seventh switch element Q7 is connected to the first end of the eleventh resistor R11.

[0258] The twenty-seventh resistor R27 can be provided to limit the current, thereby preventing the seventh switch element Q7 from being damaged by excessive current transmitted to the control electrode of the seventh switch element Q7 .

[0259] In some embodiments, Figure 3 and Fig. 9 As shown, the second voltage detection circuit 700 includes: a fifteenth resistor R15, a sixteenth resistor R16 and a third capacitor C3. The first end of the fifteenth resistor R15 is connected to the first end of the second voltage detection circuit 700, the second end of the fifteenth resistor R15 is connected to the first end of the sixteenth resistor R16, and the second end of the sixteenth resistor R16 is connected to the ground terminal. The common terminal of the fifteenth resistor R15 and the sixteenth resistor R16 is the second terminal U2_AD of the second voltage detection circuit 700. The first end of the third capacitor C3 is connected to the second terminal U2_AD of the first voltage detection circuit 600, and the second end of the third capacitor C3 is connected to the ground terminal. The second voltage signal terminal U2_AD is the common terminal of the twenty-third resistor R23 and the twenty-fourth resistor R24.

[0260] The fifteenth resistor R15 and the sixteenth resistor R16 are connected between the second terminal of the switch circuit 100 and the ground terminal to divide the voltage, and the divided voltage is output to the control circuit 900 through the second terminal U2_AD of the second voltage detection circuit 700. The third capacitor C3 is connected in parallel with the sixteenth resistor R16 to filter.

[0261] In some embodiments, Figure 3 and Figure 4 As shown, the protection circuit further includes a ninth capacitor C9, a first end of the ninth capacitor C9 is connected to the first end of the switch circuit 100, and a second end of the ninth capacitor C9 is connected to the ground end.

[0262] The ninth capacitor C9 plays a filtering role and can stabilize the voltage output from the power supply to the switch circuit 100. The number of the ninth capacitor C9 is not limited to Figure 3 As shown in , more can be set as needed.

[0263] In summary, the protection circuit provided by some embodiments of the present invention can realize real-time current detection by setting a current detection circuit 300, and can realize real-time voltage detection by using a first voltage detection circuit 600 and / or a second voltage detection circuit 700, so that the power supply condition between the power supply and the load can be detected more accurately, so as to disconnect the connection between the power supply and the load through the switching circuit 100 when there is overcurrent or undervoltage between the power supply and the load, thereby improving the reliability of power supply between the power supply and the load.

[0264] When there is an abnormal current fault (such as overcurrent or short circuit) between the power supply and the load, the comparison latch circuit 200 can latch the fault state to ensure that after the first end and the second end of the switch circuit 100 are quickly turned off, even if the current flowing through the load drops to zero, the first end and the second end of the switch circuit 100 can continue to maintain the off state.

[0265] After the abnormal current fault is relieved, the control circuit 900 sends a reset signal to release the latched state of the comparison latch circuit 200, and the comparison latch circuit 200 stops outputting the shutdown control signal to the switch circuit 100. The first and second ends of the switch circuit 100 are turned on, and the power supply and the load are turned on, so that there is a power supply abnormality between the power supply and the load. During the entire process until the abnormality is relieved, the power supply and the load can be turned on or off under the control of the protection circuit.

[0266] Since the control circuit 900 can obtain the detection current of the current detection circuit 300 in real time, even if the comparison latch circuit 200 fails and the current between the switch circuit 100 and the load exceeds the threshold current, the comparison latch circuit 200 cannot continue to send a shutdown control signal to the switch circuit 100, the control circuit 900 can also send a control signal to the switch circuit 100 to control the first and second ends of the switch circuit 100 to shut down, so as to prevent the load from being damaged by abnormal current faults such as overcurrent, thereby improving the reliability of the protection circuit.

[0267] The control circuit 900 can continuously detect the voltages at the first and second ends of the switch circuit 100 through the detection values ​​of the first voltage detection circuit 600 and the second voltage detection circuit 700. At the same time, the control circuit 900 can continuously detect the current flowing to the load through the current detection circuit 300. The control circuit 900 can also obtain the feedback signal output by the fifth end DIA_AD of the detection switch circuit 100 in real time, so as to determine whether the switch circuit 100, the comparison latch circuit 200 and the current detection circuit 300 are faulty or have potential faults.

[0268] The control circuit 900 can issue an early warning when there are hidden dangers of failure in the switching circuit 100, the comparison latch circuit 200 and the current detection circuit 300, thereby reducing the situation where the first end and the second end of the switching circuit 100 cannot be disconnected in time due to failures in the switching circuit 100, the comparison latch circuit 200 and the current detection circuit 300, resulting in damage to the load due to abnormal failures between the power supply and the load (such as undervoltage or overvoltage, overcurrent or short circuit failure), thereby providing reliability of the protection circuit.

[0269] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A protection circuit, characterized in that: include: A switch circuit (100), a comparison latch circuit (200) and a current detection circuit (300); The first end of the switch circuit (100) is connected to a power source, and the second end of the switch circuit (100) is connected to a load; the on-off of the first end and the second end of the switch circuit (100) is used to control the on-off between the power source and the load; The first end of the current detection circuit (300) is connected to the second end of the switch circuit (100), the second end of the current detection circuit (300) is connected to the load, and the third end of the current detection circuit (300) is connected to the first end of the comparison latch circuit (200); the current detection circuit (300) is used to collect the current between the switch circuit (100) and the load, and the current detection circuit (300) is also used to generate a detection voltage according to the current, and output the detection voltage; The second end of the comparison latch circuit (200) is connected to the third end of the switch circuit (100); the comparison latch circuit (200) is used to obtain the detection voltage and the first reference voltage, and when the detection voltage is greater than the first reference voltage, continuously sends a shutdown control signal to the switch circuit (100) to control the first end and the second end of the switch circuit (100) to be continuously shut down.

2. The protection circuit according to claim 1, characterized in that: The protection circuit further comprises: a reset circuit (500) and a control circuit (900); A first end of the reset circuit (500) is connected to a first end of the comparison latch circuit (200), and a second end of the reset circuit (500) is connected to the control circuit (900); The control circuit (900) is used to send a reset signal to the reset circuit (500); The reset circuit (500) is used to output a reset reference voltage to the first end of the comparison latch circuit (200) under the control of the reset signal, and the reset reference voltage is less than the first reference voltage; the comparison latch circuit (200) is also used to stop outputting the shutdown control signal when receiving the reset reference voltage.

3. The protection circuit according to claim 1, characterized in that: The protection circuit further comprises: A control circuit (900) connected to a fourth terminal (Idet_AD) of the current detection circuit (300) and a fourth terminal (SAF) of the switch circuit (100); The current detection circuit (300) is also used to transmit the collected current to the control circuit (900); The control circuit (900) is used to send a control signal to the fourth end (SAF) of the switch circuit (100) when the current is greater than a threshold current, so as to control the first end and the second end of the switch circuit (100) to be turned off.

4. The protection circuit according to claim 2 or 3, characterized in that: The protection circuit further comprises: a first voltage detection circuit (600), and / or a second voltage detection circuit (700); The first end of the first voltage detection circuit (600) is connected to the first end of the switch circuit (100), and the second end (U1_AD) of the first voltage detection circuit (600) is connected to the control circuit (900); the first voltage detection circuit (600) is used to detect the output voltage of the power supply and transmit the output voltage of the power supply to the control circuit (900); the control circuit (900) is used to control the first end and the second end of the switch circuit (100) to be turned off when the output voltage of the power supply is less than the second reference voltage or greater than the third reference voltage; The first end of the second voltage detection circuit (700) is connected to the second end of the switch circuit (100), and the second end (U2_AD) of the second voltage detection circuit (700) is connected to the control circuit (900); the second voltage detection circuit (700) is used to detect the output voltage of the switch circuit (100) and transmit the output voltage of the switch circuit (100) to the control circuit (900); the control circuit (900) is used to control the first end and the second end of the switch circuit (100) to be turned off when the output voltage is less than the fourth reference voltage or greater than the fifth reference voltage.

5. The protection circuit according to claim 4, characterized in that: When the protection circuit includes the first voltage detection circuit (600) and the second voltage detection circuit (700), the control circuit (900) is further used to control the first end and the second end of the switch circuit (100) to be turned off when the difference between the output voltage of the power supply and the output voltage of the switch circuit (100) meets a predetermined condition.

6. The protection circuit according to claim 4, characterized in that: The third terminal (KW) of the first voltage detection circuit (600) is connected to the control circuit (900); The control circuit (900) is used to transmit a detection control signal to the third end (KW) of the first voltage detection circuit (600) when the first end and the second end of the switch circuit (100) are turned on, so as to control the first end of the first voltage detection circuit (600) to be turned on with the first end of the switch circuit (100).

7. The protection circuit according to claim 2 or 3, characterized in that: The protection circuit further comprises: A reference circuit (400) connected to the third terminal of the comparison latch circuit (200); The reference circuit (400) is used to output the first reference voltage to the comparison latch circuit (200).

8. The protection circuit according to any one of claims 1 to 3, characterized in that: The protection circuit further comprises: The anti-reverse circuit (800) is connected between the power supply and the switch circuit (100) and is used to control the current to flow from the power supply to the switch circuit (100) in a unidirectional manner.

9. The protection circuit according to claim 3, characterized in that: The switch circuit comprises: a switch subcircuit (110) and a drive subcircuit (120); The first end of the switch subcircuit (110) is connected to the first end of the switch circuit (100), and the second end of the switch subcircuit (110) is connected to the second end of the switch circuit (100); The first end of the driving subcircuit (120) is connected to the third end of the switch circuit (100), and the second end of the driving subcircuit (120) is connected to the fourth end (SAF) of the switch circuit (100); The third end of the switch subcircuit (110) is connected to the third end of the drive subcircuit (120); The driving subcircuit (120) is used to control the switch subcircuit (110) to switch off the first end and the second end of the switch circuit (100) based on the switch control signal.

10. The protection circuit according to claim 9, characterized in that: The switch subcircuit (110) comprises: A first switch element (Q1), wherein a control electrode of the first switch element (Q1) is connected to a third end of the switch subcircuit (110), a first electrode of the first switch element (Q1) is connected to a first end of the switch subcircuit (110), and a second electrode of the first switch element (Q1) is connected to a second end of the switch subcircuit (110).

11. The protection circuit according to claim 10, characterized in that: The switch subcircuit (110) further includes: at least one of a first diode (D1), a first resistor (R1) and a first capacitor (C1); A first electrode of the first diode (D1) is connected to a control electrode of the first switch element (Q1), and a second electrode of the first diode (D1) is connected to a first electrode of the first switch element (Q1); A first end of the first resistor (R1) is connected to a control electrode of the first switch element (Q1), and a second end of the first resistor (R1) is connected to a first electrode of the first switch element (Q1); A first end of the first capacitor (C1) is connected to a control electrode of the first switch element (Q1), and a second end of the first capacitor (C1) is connected to a first electrode of the first switch element (Q1).

12. The protection circuit according to claim 10 or 11, characterized in that: The switch subcircuit (110) further includes: a second resistor (R2), a second switch element (Q2) and a second diode (D2); The control electrode of the second switch element (Q2) is connected to the third end of the switch sub-circuit (110), the first electrode of the second switch element (Q2) is connected to the first end of the switch sub-circuit (110), and the second electrode of the second switch element (Q2) is connected to the control electrode of the first switch element (Q1); The first end of the second resistor (R2) is connected to the first end of the switch subcircuit (110), and the second end of the second resistor (R2) is connected to the control electrode of the second switch element (Q2); A first end of the second diode (D2) is connected to a second electrode of the second switch element (Q2), and a second end of the second diode (D2) is connected to a control electrode of the first switch element (Q1).

13. The protection circuit according to claim 9, characterized in that: The driving subcircuit (120) comprises: a third switch element (Q3) and a fourth switch element (Q4); The control electrode of the third switch element (Q3) is connected to the second end of the drive subcircuit (120), the first electrode of the third switch element (Q3) is connected to the third end of the drive subcircuit (120), and the second electrode of the third switch element (Q3) is connected to the ground end; The control electrode of the fourth switch element (Q4) is connected to the first end of the drive subcircuit (120), the first electrode of the fourth switch element (Q4) is connected to the control electrode of the third switch element (Q3), and the second electrode of the fourth switch element (Q4) is connected to the ground end.

14. The protection circuit according to claim 13, characterized in that: The driving subcircuit (120) further includes: a third resistor (R3) and a fourth resistor (R4); The first end of the third resistor (R3) is connected to the control electrode of the third switch element (Q3), the second end of the third resistor (R3) is connected to the first end of the fourth resistor (R4), and the second end of the fourth resistor (R4) is connected to the ground end; The common terminal of the third resistor (R3) and the fourth resistor (R4) is the second terminal of the driving sub-circuit (120).

15. The protection circuit according to claim 13, characterized in that: The driving subcircuit (120) further includes: a fifth resistor (R5) and a sixth resistor (R6); The first end of the fifth resistor (R5) is connected to the control electrode of the third switch element (Q3), the second end of the fifth resistor (R5) is connected to the first end of the sixth resistor (R6), and the second end of the sixth resistor (R6) is connected to the ground end; The common terminal of the fifth resistor (R5) and the sixth resistor (R6) is the fifth terminal (DIA_AD) of the switch circuit (100), and the fifth terminal (DIA_AD) of the switch circuit (100) is connected to the control circuit (900); The fifth terminal (DIA_AD) of the switch circuit (100) is used to output a feedback signal to the control circuit (900), wherein the feedback signal is used to represent the conduction state of the fourth switch element (Q4).

16. The protection circuit according to claim 1, characterized in that: The comparison latch circuit (200) comprises: a first chip (U1), a seventh resistor (R7) and a third diode (D3); The first input end of the first chip (U1) is connected to the first end of the comparison latch circuit (200), the second input end of the first chip (U1) is connected to the third end of the comparison latch circuit (200), and the output end of the first chip (U1) is connected to the second end of the switch circuit (100); The first end of the seventh resistor (R7) is connected to the output end of the first chip (U1), the second end of the seventh resistor (R7) is connected to the first end of the third diode (D3), and the second end of the third diode (D3) is connected to the first input end of the first chip (U1).

17. The protection circuit according to claim 16, characterized in that: The comparison latch circuit (200) further includes: a fifth switch element (Q5); The control electrode of the fifth switch element (Q5) is connected to the output end of the first chip (U1), the first electrode of the fifth switch element (Q5) is connected to the power signal end (VCC), and the second electrode of the fifth switch element (Q5) is connected to the second end of the comparison latch circuit (200).

18. The protection circuit according to claim 1, characterized in that: The current detection circuit (300) comprises: a second chip (U2) and an eighth resistor (R8); The first end of the eighth resistor (R8) is connected to the first end of the current detection circuit (300), and the second end of the eighth resistor (R8) is connected to the second end of the current detection circuit (300); The first input end of the second chip (U2) is connected to the first end of the eighth resistor (R8), the second input end of the second chip (U2) is connected to the second end of the eighth resistor (R8), and the output end of the second chip (U2) is connected to the third end of the current detection circuit (300).

19. The protection circuit according to claim 2, characterized in that: The reset circuit (500) comprises: a sixth switch element (Q6), a ninth resistor (R9) and a tenth resistor (R10); The first end of the ninth resistor (R9) is connected to the ground end, the second end of the ninth resistor (R9) is connected to the first end of the tenth resistor (R10), the second end of the tenth resistor (R10) is connected to the control electrode of the sixth switch element (Q6), the first electrode of the sixth switch element (Q6) is connected to the first end of the reset circuit (500), and the second electrode of the sixth switch element (Q6) is connected to the ground end; The common terminal of the ninth resistor (R9) and the tenth resistor (R10) is the second terminal (REST) ​​of the reset circuit (500).

20. The protection circuit according to claim 6, characterized in that: The first voltage detection circuit (600) comprises: an eleventh resistor (R11), a twelfth resistor (R12) and a second capacitor (C2); The first end of the eleventh resistor (R11) is connected to the first end of the first voltage detection circuit (600), the second end of the eleventh resistor (R11) is connected to the first end of the twelfth resistor (R12), and the second end of the twelfth resistor (R12) is connected to the ground end; The common terminal of the eleventh resistor (R11) and the twelfth resistor (R12) is the second terminal (U1_AD) of the first voltage detection circuit (600); A first end of the second capacitor (C2) is connected to a second end (U1_AD) of the first voltage detection circuit (600), and a second end of the second capacitor (C2) is connected to the ground end.

21. The protection circuit according to claim 20, characterized in that: The first voltage detection circuit (600) further includes: a seventh switch element (Q7), an eighth switch element (Q8), a thirteenth resistor (R13) and a fourteenth resistor (R14); The first end of the thirteenth resistor (R13) is connected to the third end (KW) of the first voltage detection circuit (600), the second end of the thirteenth resistor (R13) is connected to the first end of the fourteenth resistor (R14), and the second end of the fourteenth resistor (R14) is connected to the ground end; A common terminal of the thirteenth resistor (R13) and the fourteenth resistor (R14) is connected to a control electrode of the eighth switch element (Q8), a first electrode of the eighth switch element (Q8) is connected to a control electrode of the seventh switch element (Q7), and a second electrode of the eighth switch element (Q8) is connected to the ground terminal; A first electrode of the seventh switch element (Q7) is connected to a first end of the first voltage detection circuit (600), and a second electrode of the seventh switch element (Q7) is connected to a first end of the eleventh resistor (R11).

22. The protection circuit according to claim 4, characterized in that: The second voltage detection circuit (700) comprises: a fifteenth resistor (R15), a sixteenth resistor (R16) and a third capacitor (C3); The first end of the fifteenth resistor (R15) is connected to the first end of the second voltage detection circuit (700), the second end of the fifteenth resistor (R15) is connected to the first end of the sixteenth resistor (R16), and the second end of the sixteenth resistor (R16) is connected to the ground end; The common terminal of the fifteenth resistor (R15) and the sixteenth resistor (R16) is the second terminal (U2_AD) of the second voltage detection circuit (700); A first end of the third capacitor (C3) is connected to a second end (U2_AD) of the first voltage detection circuit (600), and a second end of the third capacitor (C3) is connected to the ground end.

23. The protection circuit according to claim 7, characterized in that: The reference circuit (400) comprises: a seventeenth resistor (R17) and an eighteenth resistor (R18); The first end of the seventeenth resistor (R17) is connected to the ground end, the second end of the seventeenth resistor (R17) is connected to the first end of the eighteenth resistor (R18), and the second end of the eighteenth resistor (R18) is connected to the power signal end (VCC); A common terminal (REF) of the seventeenth resistor (R17) and the eighteenth resistor (R18) is connected to a third terminal of the comparison latch circuit (200).

24. An electronic device, characterized in that: include: A power supply, a load, and a protection circuit as claimed in any one of claims 1 to 23.

25. A vehicle, characterized in that: include: Vehicle body; and, The electronic device according to claim 24 is arranged in the vehicle body.

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