Overvoltage protection circuit and electronic equipment

Abstract

The invention provides an overvoltage protection circuit comprising a signal acquisition module used for acquiring an electric signal in a charging and discharging circuit; the input end of the charging and discharging control module is electrically connected with the output end of the signal acquisition module, and a control signal is generated according to the electric signal in the charging and discharging circuit; the control end of the overvoltage protection switch is electrically connected with the output end of the charging and discharging control module, the first end of the overvoltage protection switch is electrically connected with external equipment, and the second end of the overvoltage protection switch is electrically connected with a load; and when the control signal is a turn-off signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch so as to disconnect the electrical connection between the external equipment and the load. The invention further provides an electronic device.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and in particular to an overvoltage protection circuit and an electronic device. Background Art

[0002] An overvoltage protection circuit is a circuit that is set in an electronic device to increase the service life. For example, in a charging device, setting an overvoltage protection circuit can protect the service life of the charging device. In current charging devices, the voltage protection circuit needs to use a charging chip to control the charging process. However, the charging chip is expensive and the control logic is complex. Summary of the invention

[0003] The present invention provides an overvoltage protection circuit and an electronic device.

[0004] In a first aspect, an embodiment of the present disclosure provides an overvoltage protection circuit, including:

[0005] A signal acquisition module, used for collecting electrical signals in the charging and discharging circuit;

[0006] A charge and discharge control module, whose input end is electrically connected to the output end of the signal acquisition module and generates a control signal according to the electrical signal in the charge and discharge circuit;

[0007] An overvoltage protection switch, wherein a control end of the overvoltage protection switch is electrically connected to an output end of the charge and discharge control module, a first end of the overvoltage protection switch is electrically connected to the external device, and a second end of the overvoltage protection switch is electrically connected to a load;

[0008] In the case where the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch to disconnect the electrical connection between the external device and the load.

[0009] In a second aspect, an embodiment of the present disclosure provides an electronic device, comprising: a load and an overvoltage protection circuit, wherein in the case of charging, an external device provides power to the load; in the case of discharging, the load provides power to the external device, and the overvoltage protection circuit is arranged between the external device and the load;

[0010] The overvoltage protection circuit includes the overvoltage protection circuit provided in an embodiment of the present disclosure, and the overvoltage protection circuit generates a control signal according to the electrical signal in the charging and discharging circuit. When the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch to disconnect the electrical connection between the external device and the load.

[0011] In the overvoltage protection circuit in the embodiment of the present disclosure, the charge and discharge control module generates a control signal according to the electrical signal in the charge and discharge circuit collected by the signal acquisition module, the control end of the overvoltage protection switch is electrically connected to the output end of the charge and discharge control module, the first end of the overvoltage protection switch is electrically connected to the external device, and the second end is electrically connected to the load. When the control signal is an off signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch, thereby disconnecting the electrical connection between the external device and the load, that is, overvoltage protection is achieved through electronic devices, which is low in cost compared to charging chips and has a simple control logic. The parameters of the electronic devices can also be adjusted according to the needs of the overvoltage protection scenario, thereby improving the flexibility of the overvoltage protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the accompanying drawings of the embodiments of the present disclosure:

[0013] Figure 1 A block diagram of an overvoltage protection circuit provided in an embodiment of the present disclosure;

[0014] Figure 2 A schematic diagram of the structure of an overvoltage protection circuit provided by an embodiment of the present disclosure;

[0015] Figure 3 A schematic diagram of the structure of another overvoltage protection circuit provided by an embodiment of the present disclosure;

[0016] Figure 4 A schematic diagram of a charging circuit provided in an embodiment of the present disclosure;

[0017] Figure 5 A schematic diagram of a charging circuit provided in an embodiment of the present disclosure;

[0018] Figure 6 A schematic diagram of a discharge circuit provided in an embodiment of the present disclosure;

[0019] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0021] The present disclosure will be described more fully below with reference to the accompanying drawings, but the embodiments shown may be embodied in different forms, and the present disclosure should not be construed as being limited to the embodiments set forth below. On the contrary, the purpose of providing these embodiments is to make the present disclosure thorough and complete, and will enable those skilled in the art to fully understand the scope of the present disclosure.

[0022] The accompanying drawings of the embodiments of the present disclosure are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the specification, and are used together with the detailed embodiments to explain the present disclosure, and do not constitute a limitation of the present disclosure. By describing the detailed embodiments with reference to the accompanying drawings, the above and other features and advantages will become more apparent to those skilled in the art.

[0023] The present disclosure may be described with reference to plan views and / or cross-sectional views by means of ideal schematic views of the present disclosure. Therefore, the exemplary illustrations may be modified according to manufacturing techniques and / or tolerances.

[0024] In the absence of conflict, the various embodiments of the present disclosure and the various features therein may be combined with each other.

[0025] The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure. The term "and / or" as used in the present disclosure includes any and all combinations of one or more related enumerated items. The singular forms "one" and "the" as used in the present disclosure are also intended to include plural forms, unless the context clearly indicates otherwise. The terms "including", "made of..." as used in the present disclosure specify the presence of the features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meaning as commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning unless explicitly defined in this disclosure.

[0027] In some related technologies, the charging and discharging circuit achieves overvoltage protection through a charging chip. However, the charging chip is expensive, and the charging chip is an integrated device with multiple built-in control logics, which makes the overvoltage protection logic complicated. Therefore, it is necessary to develop an overvoltage protection circuit with low price and simple control logic.

[0028] In a first aspect, an embodiment of the present disclosure provides an overvoltage protection circuit.

[0029] Figure 1 Schematic diagram of an overvoltage protection circuit provided by an embodiment of the present disclosure. Figure 1 As shown, the overvoltage protection circuit provided by the embodiment of the present disclosure includes:

[0030] The signal acquisition module 10 is used to acquire the electrical signal in the charge and discharge circuit, wherein the electrical signal includes at least one of a voltage signal and a current signal.

[0031] The charge and discharge control module 20 has an input end electrically connected to the output end of the signal acquisition module 10 and generates a control signal according to the electrical signal in the charge and discharge circuit.

[0032] The control signal includes a shut-off signal and a conduction signal. When the charge-discharge circuit is over-voltage, the charge-discharge control module 20 generates a shut-off signal. When the charge-discharge circuit is not over-voltage, the charge-discharge control module 20 generates a conduction signal.

[0033] The overvoltage protection switch 30 has a control end electrically connected to the output end of the charge and discharge control module, a first end electrically connected to the external device 3, and a second end electrically connected to the load 4. When the control signal is a shutdown signal, the overvoltage protection switch 30 disconnects the electrical connection between the first end and the second end to disconnect the electrical connection between the external device 3 and the load 4.

[0034] It should be noted that in the embodiment of the present disclosure, charging is also referred to as internal charging, and discharging is also referred to as external discharging. For ease of description, the present disclosure is referred to as charging and discharging. During charging, the external device 3 provides power to the load 4. At this time, the load 4 includes a battery and other circuits in the device except the battery. During discharging, the load 4 supplies power to the external device 3. At this time, the load 4 includes a battery.

[0035] In the overvoltage protection circuit in the embodiment of the present disclosure, the charge and discharge control module generates a control signal according to the electrical signal in the charge and discharge circuit collected by the signal acquisition module, the control end of the overvoltage protection switch is electrically connected to the output end of the charge and discharge control module, the first end of the overvoltage protection switch is electrically connected to the external device, and the second end is electrically connected to the load. When the control signal is an off signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch, thereby disconnecting the electrical connection between the external device and the load, that is, overvoltage protection is achieved through electronic devices, which is low in cost compared to charging chips and has a simple control logic. The parameters of the electronic devices can also be adjusted according to the needs of the overvoltage protection scenario, thereby improving the flexibility of the overvoltage protection circuit.

[0036] In some embodiments, Figure 2 As shown, the charging and discharging circuit provided in the embodiment of the present disclosure includes a charging circuit 1, and the charging circuit 1 is used to realize the charging of the load 4 by the external device 3. At this time, the load 4 includes the battery in the device and other circuits except the battery. The charging circuit 1 provided in the embodiment of the present disclosure includes:

[0037] The signal acquisition module includes a voltage detection module 11, which is used to detect the voltage input by the external device 3 and output the detection voltage.

[0038] The voltage detection module 11 may be any module that can measure voltage. For example, the voltage detection module 11 includes a voltage measuring instrument.

[0039] The charge and discharge control module includes a charge control module, and the charge control module includes a comparator 12. The first input end of the comparator 12 inputs a reference voltage, and the second input end is electrically connected to the output end of the voltage detection module 11. The output end of the comparator 12 outputs a control signal. Among them, the control signal includes a shutdown signal and a connection signal. When the detection voltage is higher than the reference voltage, the output end of the comparator 12 outputs a shutdown signal. When the detection voltage is lower than the reference voltage, the output end of the comparator 12 outputs a connection signal.

[0040] The overvoltage protection switch includes a first control switch 13, a control end of the first control switch 13 is electrically connected to the output end of the comparator 12, a first end is electrically connected to an external device, and a second end is electrically connected to a load. The first control switch 13 controls the on and off of the first end and the second end according to a control signal output by the comparator 12.

[0041] When the detection voltage is higher than the reference voltage, the comparator 12 outputs a shutdown signal, and the first control switch 13 disconnects the external device 3 from the load 4 in response to the shutdown signal.

[0042] In the overvoltage protection circuit in the embodiment of the present disclosure, in the charging loop, the first input terminal of the comparator inputs a reference voltage, the second input terminal is electrically connected to the output terminal of the voltage detection module, the control terminal of the first control switch is electrically connected to the output terminal of the comparator, the first terminal is electrically connected to the external device, and the second terminal is electrically connected to the load. When the detection voltage is higher than the reference voltage, the comparator outputs a shutdown signal, and the first control switch disconnects the electrical connection between the external device and the load in response to the shutdown signal. This overvoltage protection circuit built with electronic devices has a low cost compared to a charging chip and a simple control logic. The parameters of the electronic devices can be adjusted according to the needs of the overvoltage protection scenario, thereby improving the flexibility of the overvoltage protection circuit.

[0043] In some embodiments, the charging control module further includes: a level adjustment module 14, which is connected in series between the output end of the comparator 12 and the control end of the first control switch 13, and when the comparator 12 outputs a shutdown signal, the potential of the control end of the first control switch 13 reaches the shutdown potential.

[0044] In the embodiment of the present disclosure, when the comparator 12 outputs a shutdown signal, the level adjustment module 14 can make the potential of the control end of the first control switch 13 quickly reach the shutdown potential.

[0045] In some embodiments, the level adjustment module 14 includes: a first diode D1 and a first resistor R1, wherein the cathode of the first diode D1 is electrically connected to the output end of the comparator 12, and the anode is electrically connected to the control end of the first control switch 13. The first end of the first resistor R1 is electrically connected to the output end of the comparator 12, and the second end is electrically connected to the control end of the first control switch 13.

[0046] The first resistor R1 is a current limiting resistor, which can prevent the current flowing into the first control switch 13 from being too large.

[0047] In the embodiment of the present disclosure, the shutdown signal and the connection signal may be level signals. For example, the shutdown signal is at a low level and the connection signal is at a high level; or, the shutdown signal is at a high level and the connection signal is at a low level.

[0048] In some embodiments, the first control switch 13 may be a MOS tube. The levels of the shutdown signal and the connection signal may be determined according to the type of the first control switch 13. For example, when the first control switch 13 is an N-type MOS tube, the shutdown signal is a low level and the connection signal is a high level. When the first control switch 13 is a P-type MOS tube, the shutdown signal is a high level and the connection signal is a low level.

[0049] The following is an introduction using the first control switch 13 as an N-type MOS tube as an example. When the detection voltage is lower than the reference voltage, the comparator 12 outputs a high level, the gate of the N-type MOS tube is at a high level, the N-type MOS tube is turned on, and the external device 3 charges the load 4. When the detection voltage is higher than the reference voltage, the output of the comparator 12 changes from a high level to a low level, the positive electrode voltage of the first diode D1 is higher than the negative electrode voltage, the current flows from the positive electrode to the negative electrode of the first diode D1, the level of the gate of the N-type MOS tube is rapidly pulled down, the N-type MOS tube is rapidly turned off, and the load 4 is protected from overvoltage.

[0050] In some embodiments, the charging control module further includes a main control module 15 and a control circuit 17 , wherein an input end of the main control module is electrically connected to the voltage detection module 11 , and a first output end is electrically connected to an input end of the comparator 12 .

[0051] In some embodiments, Figure 3 As shown, the main control module 15 includes a standard voltage setting circuit 151 and a main chip 152, wherein the standard voltage setting circuit 151 is used to set a reference voltage, and an output end is electrically connected to a first input end of the comparator 12. In the embodiment of the present disclosure, the reference voltage is set according to the charging voltage, and the reference voltage is not higher than the rated voltage of each device in the load and the charging circuit.

[0052] When the charging circuit is in the charging state, the input end of the main chip 152 is electrically connected to the voltage detection module 11, and the first output end is electrically connected to the input end of the standard voltage setting circuit 151. In some embodiments, the main chip 152 can set the reference voltage according to the charging voltage, and the standard voltage setting circuit 151 sets the reference voltage according to the reference voltage determined by the main chip 152.

[0053] An input end of the control circuit 17 is electrically connected to the second output end of the main chip 152 for receiving a control signal of the main chip 152 , and an output end of the control circuit 17 is electrically connected to an enable end of the comparator 12 .

[0054] Figure 4 This is a schematic diagram of a charging circuit provided by an embodiment of the present disclosure. Figure 4 As shown, the control circuit 17 includes:

[0055] The second resistor R2 has a first end electrically connected to the second output end of the main chip 152 .

[0056] A third resistor R3, a first end of the third resistor R3 is electrically connected to the second end of the second resistor R2, and a second end of the third resistor R3 is grounded;

[0057] The first switch tube M1 has a gate electrically connected to the second end of the second resistor R2 and a source grounded.

[0058] The second switch tube M2 has a gate electrically connected to the drain of the first switch tube M1 and a source grounded.

[0059] The third switch tube M3 has a gate electrically connected to the drain of the second switch tube M2 , a source electrically connected to the external device 3 , and a drain electrically connected to the second input terminal of the comparator 12 .

[0060] A fourth resistor R4 , a first end of the fourth resistor R4 is electrically connected to the pull-up power source 18 , and a second end of the fourth resistor R4 is electrically connected to the gate of the second switch tube M2 .

[0061] The first switch tube M1, the second switch tube M2 and the third switch tube M3 may be NMOS tubes or PMOS tubes. For example, the first switch tube M1 and the second switch tube M2 may be NMOS tubes, and the third switch tube M3 may be PMOS tubes.

[0062] In the embodiment of the present disclosure, the pull-up power supply 18 is a power supply of an external device, and the voltage of the pull-up power supply can be set as needed, which is not limited in the embodiment of the present disclosure.

[0063] The second resistor R2 and the third resistor R3 can keep the gate of the first switch tube M1 at a high level when the main chip 152 outputs a control signal. When the main chip 152 does not output a control signal, the third resistor R3 can also keep the gate of the first switch tube M1 at a low level to turn off the first switch tube M1.

[0064] In some embodiments, the control circuit 17 further includes a fifth resistor R5 , a first end of the fifth resistor R5 is electrically connected to the external device 3 , and a second end of the fifth resistor R5 is electrically connected to the drain of the second switch tube M2 .

[0065] In some embodiments, the charging circuit further comprises:

[0066] A sixth resistor R6 , wherein a first end of the sixth resistor R6 is electrically connected to the second output end of the main chip 152 .

[0067] A seventh resistor R7, a first end of the seventh resistor R7 is electrically connected to the second end of the sixth resistor R6, and a second end of the seventh resistor R7 is grounded.

[0068] The fourth switch tube M4 has a gate electrically connected to the second end of the sixth resistor R6 , a source electrically connected to the ground, and a drain electrically connected to the control end of the first control switch 13 .

[0069] The sixth resistor R6, the seventh resistor R7 and the fourth switch tube M4 can realize the on-off control of the first control switch 13. When manual control is required, the main chip 152 can send a main chip control signal to control the fourth switch tube M4, thereby controlling the on-off of the first control switch 13.

[0070] In some embodiments, the fourth switch tube M4 may be an NMOS tube or a PMOS tube. The embodiment of the present disclosure takes the NMOS tube as an example for description.

[0071] The sixth resistor R6 and the seventh resistor R7 can keep the gate of the fourth switch tube M4 at a high level when the master chip 152 outputs a control signal. When the master chip 152 does not output a control signal, the seventh resistor R7 can also keep the gate of the fourth switch tube M4 at a low level to turn off the fourth switch tube M4.

[0072] Figure 5 A schematic diagram of a charging circuit provided by an embodiment of the present disclosure. Figure 4 and Figure 5, the external device 3 charges the load 4 through the USB interface 5, the main chip 152 control signal detects that the external device 3 is charging the load 4, the gates of the first switch tube M1 and the fourth switch tube M4 are low level, the first switch tube M1 and the fourth switch tube M4 are turned off, the second switch tube M2 is turned on, the gate of the third switch tube M3 is low level, the third switch tube M3 is turned on, and the power input by the external device 3 enters the second input terminal of the comparator 12 through the third switch tube M3, and the comparator 12 compares it with the reference voltage. When the voltage of the external device 3 is higher than the reference voltage, the comparator 12 outputs a low level, the gate of the fifth switch tube M5 is quickly pulled to a low level through the first diode, the fifth switch tube M5 is quickly turned off, and the fifth switch tube M5 quickly disconnects the electrical connection between the load 4 and the external device 3, and the overvoltage electrical signal does not enter the load 4.

[0073] When the voltage of the external device 3 returns to normal, that is, the voltage of the external device 3 is lower than the reference voltage, the comparator 12 outputs a high level, the gate of the fifth switch tube M5 returns to a high level, the fifth switch tube M5 is turned on again, and the power of the external device 3 flows through the fifth switch tube M5 to charge the load 4.

[0074] When the main chip 152 does not detect the charging behavior of the external device, the control signal of the main chip 152 is a high level signal.

[0075] In some embodiments, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the fifth switch tube can be electronic devices such as NMOS tubes or PMOS tubes that can control the on and off of a circuit.

[0076] In some embodiments, the charge and discharge circuit further includes a discharge loop 2 , and the discharge loop 2 is used for a load 4 to supply power to an external device 3 . In this case, the load 4 includes a battery of the device.

[0077] Figure 6 A schematic diagram of a discharge circuit provided by an embodiment of the present disclosure. Figure 2 , Figure 3 and Figure 6 , in the discharge circuit 2, the signal acquisition module includes:

[0078] The current detection module is used to monitor the flow direction of the current in the discharge circuit. In the discharge circuit, the current flow direction includes a first flow direction IN1 and a second flow direction IN2. The first flow direction IN1 flows from the external device 3 to the load 4, and the second flow direction IN2 flows from the load 4 to the external device 3.

[0079] The charge and discharge control module includes a discharge control module 21 that generates a control signal based on the flow direction of the current.

[0080] The first end of the unidirectional conductive device 22 is electrically connected to the external device 3 , and the unidirectional conductive device 22 can only allow current to flow from the load 4 to the external device 3 , thereby ensuring that the current flows to the load 4 during the discharge process.

[0081] The overvoltage protection switch includes a second control switch 23 , a first end of the second control switch 23 is electrically connected to the second end of the unidirectional conductive device 22 , a second end is electrically connected to the load 4 , and a control end is electrically connected to the output end of the discharge control module 21 .

[0082] When the current flows from the external device 3 to the load 4 , the control signal is a shutdown signal, and the second control switch 23 is turned off in response to the shutdown signal, thereby disconnecting the electrical connection between the external device 3 and the load 4 .

[0083] When the current flows from the load 4 to the external device 3 , the control signal is a connection signal, and the second control switch 23 is closed in response to the connection signal, thereby electrically connecting the external device 3 to the load 4 .

[0084] In some embodiments, the discharge control module 21 includes:

[0085] The second diode D2 has an anode electrically connected to the load, and a cathode electrically connected to the external device.

[0086] The third diode D3 has an anode electrically connected to the external device, and a cathode electrically connected to the load.

[0087] The filter circuit 24 has a first input terminal electrically connected to the load 4, and is also electrically connected to the anode of the second diode and the cathode of the third diode; the second input terminal is electrically connected to the external device 3, and is also electrically connected to the cathode of the second diode and the anode of the third diode.

[0088] The operational amplifier unit 25 has a positive electrode electrically connected to the first input terminal of the filter circuit 24 , and a negative electrode electrically connected to the second input terminal of the filter circuit 24 .

[0089] In some embodiments, the filter circuit 24 includes:

[0090] A ninth resistor R9 , a first end of the ninth resistor R9 is electrically connected to the load, and is also electrically connected to the anode of the second diode and the cathode of the third diode; a second end of the ninth resistor R9 is electrically connected to the anode of the operational amplifier unit 25 .

[0091] The tenth resistor R10 has a first end electrically connected to the external device, and is also electrically connected to the cathode of the second diode and the anode of the third diode, and a second end electrically connected to the cathode of the operational amplifier unit 25 .

[0092] The first capacitor has a first end electrically connected to the positive electrode of the operational amplifier unit 25 and to the second end of the ninth resistor R9; the second end is electrically connected to the negative electrode of the operational amplifier unit 25 and to the second end of the tenth resistor R10.

[0093] Under normal circumstances, the load 4 discharges to the outside through the second control switch 23 and the unidirectional conduction device 22, and the discharge control module 21 is used to monitor the flow direction of the current in the discharge loop, and the load controls the operational amplifier unit 25 through the control pin to start working. When the current flows to the load 3 through the USB interface 5, the current is input into the discharge control module 21 through the first flow direction IN1, and the first path passes through the third diode and the ninth resistor R9 to enter the "+" level of the operational amplifier unit 25, and the second path passes through the tenth resistor R10 to enter the "-" level of the operational amplifier unit 25. Therefore, the voltage of the "+" level is less than the "-", and the discharge control module 21 determines that the current flows from the external device 4 to the load 3, and the operational amplifier unit 25 outputs a low level. The second control switch 23 responds to the low level to disconnect the current path between the external device 4 and the load 3, thereby protecting the load 4.

[0094] It should be noted that in the discharge loop, the unidirectional conductive device 22 can be combined with the discharge control module 21 to prevent the external device 3 from causing current to flow reversely into the load 4, and also prevent the external device 3 from damaging the load 4 due to overvoltage.

[0095] When the current flows from the load 4 to the external device 3, the current is input into the discharge control module 21 through the second flow IN2, the first current passes through the second diode and the tenth resistor R10 to enter the "-" level of the operational amplifier unit 25, and the second current passes through the ninth resistor R9 to enter the "+" level of the operational amplifier unit 25. Therefore, the voltage of the "-" level is smaller than the "+" level. The discharge control module 21 determines that the current flows from the load 4 to the external device 3, the operational amplifier unit 25 outputs a high level, and the second control switch 23 is closed in response to the high level. The current path between the external device 3 and the load 4 is turned on, and the load 4 supplies power to the external device 3 normally.

[0096] In some embodiments, the unidirectional conductive device 22 includes a device having a unidirectional conductive function such as a diode or a MOS tube. When the unidirectional conductive device 22 is a diode, the anode of the diode is electrically connected to the first end of the second control switch 23, and the cathode is electrically connected to the external device. When the unidirectional conductive device includes a MOS tube, the drain of the MOS tube is electrically connected to the first end of the second control switch 23, the source is electrically connected to the external device 3, and the gate is electrically connected to the output end of the discharge control module 21.

[0097] In some embodiments, there is a charging or discharging relationship between the external device 3 and the load 4. When charging, the external device 3 and the load 4 are electrically connected through the charging circuit. When discharging, the external device 3 and the load 4 are electrically connected through the discharging circuit, and the discharging circuit and the charging circuit are two different circuits. Therefore, the overvoltage protection circuit also includes a charge and discharge detection circuit and a switching switch.

[0098] like Figure 2 and Figure 3 As shown, the overvoltage protection circuit also includes a charge and discharge detection circuit 6 and a switch 7, wherein the charge and discharge detection circuit 6 is used to determine whether the external device is electrically connected to the charging circuit or the discharging circuit. The input end of the switch 7 is electrically connected to the external device, the first output end is electrically connected to the discharging circuit, and the second output end is electrically connected to the charging circuit.

[0099] In some embodiments, the charge and discharge detection circuit 6 negotiates with the load 4 whether to charge or discharge. When the negotiation is for internal charging, the charge and discharge detection circuit 6 switches the switching switch 7 to the charging circuit; when the negotiation is for external discharge, the charge and discharge detection circuit 6 switches the switching switch 7 to the discharge circuit.

[0100] The overvoltage protection circuit provided in this application can be applied not only to electronic products such as MI FI and mobile phones that only need a charging circuit, but also to charging and discharging electronic products such as mobile power banks.

[0101] It should be noted that in the embodiments of the present disclosure, the charge and discharge circuit may include only a charge circuit or a discharge circuit, or the charge and discharge circuit includes a charge circuit and a discharge circuit. The overvoltage protection circuit provides overvoltage protection for the charge circuit during charging and provides overvoltage protection for the discharge circuit during discharging.

[0102] In a second aspect, an embodiment of the present disclosure provides an electronic device.

[0103] Figure 7 The structure diagram of an electronic device provided by the embodiment of the present disclosure is shown in FIG. Figure 7 As shown, the electronic device includes: a load 61 and an overvoltage protection circuit 62. In the case of charging, an external device 63 provides power to the load 61; in the case of discharging, the electronic device provides power to the external device 63.

[0104] It should be noted that, in the case of charging, the load 61 includes the battery in the electronic device and other circuits except the battery, and the external device 63 charges the battery and also provides power to other circuits except the battery. When discharging, the battery in the electronic device can provide power to the external device 63.

[0105] The overvoltage protection circuit 62 may adopt the overvoltage protection circuit provided in the embodiment of the present disclosure, and the specific structure and control logic are not described in detail here.

[0106] When the overvoltage protection circuit 62 detects that the voltage inputted by the external device is higher than a preset reference voltage, it disconnects the electrical connection between the external device 63 and the load 61 .

[0107] In the electronic device in the embodiment of the present disclosure, the charge and discharge control module generates a control signal according to the electrical signal in the charge and discharge circuit collected by the signal acquisition module, the control end of the overvoltage protection switch is electrically connected to the output end of the charge and discharge control module, the first end of the overvoltage protection switch is electrically connected to the external device, and the second end is electrically connected to the load. When the control signal is an off signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch, thereby disconnecting the electrical connection between the external device and the load, that is, overvoltage protection is achieved through electronic devices, which is low in cost compared to charging chips, reduces the cost of electronic devices, and has a simple control logic, which simplifies the control logic of electronic devices. The parameters of the electronic devices can also be adjusted according to the needs of overvoltage protection scenarios, thereby improving the flexibility of the overvoltage protection circuit and expanding the application range of electronic devices.

[0108] The present disclosure has disclosed example embodiments, and although specific terms are employed, they are used and should be interpreted only in a general illustrative sense and not for limiting purposes. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly stated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. An overvoltage protection circuit, comprising: A signal acquisition module, used for collecting electrical signals in the charging and discharging circuit; A charge and discharge control module, whose input end is electrically connected to the output end of the signal acquisition module and generates a control signal according to the electrical signal in the charge and discharge circuit; An overvoltage protection switch, wherein a control end of the overvoltage protection switch is electrically connected to an output end of the charge and discharge control module, a first end of the overvoltage protection switch is electrically connected to an external device, and a second end of the overvoltage protection switch is electrically connected to a load; In the case where the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch to disconnect the electrical connection between the external device and the load.

2. The overvoltage protection circuit according to claim 1, wherein: The charging and discharging circuit comprises a charging circuit: The signal acquisition module includes a voltage detection module, which is used to detect the voltage input by the external device and output the detection voltage; The charge and discharge control module includes a charge control module, the charge control module includes a comparator, a first input terminal of the comparator inputs a reference voltage, a second input terminal is electrically connected to an output terminal of the voltage detection module, and an output terminal of the comparator outputs the control signal; The overvoltage protection switch comprises a first control switch, wherein a control end of the first control switch is electrically connected to the output end of the comparator, a first end is electrically connected to the external device, and a second end is electrically connected to the load; When the detection voltage is higher than the reference voltage, the comparator outputs a shutdown signal, and the first control switch disconnects the external device from the load in response to the shutdown signal.

3. The overvoltage protection circuit according to claim 2, wherein: The charging control module further includes: The level adjustment module is connected in series between the output end of the comparator and the control end of the first control switch, and makes the potential of the control end of the first control switch reach the shutdown potential when the comparator outputs a shutdown signal.

4. The overvoltage protection circuit according to claim 3, wherein: The level adjustment module comprises: a first diode, wherein a cathode of the first diode is electrically connected to the output terminal of the comparator, and an anode of the first diode is electrically connected to the control terminal of the first control switch; A first resistor, wherein a first end of the first resistor is electrically connected to the output end of the comparator, and a second end of the first resistor is electrically connected to the control end of the first control switch.

5. The overvoltage protection circuit according to claim 2, wherein: The charging control module further includes: A main control module, wherein an input terminal of the main control module is electrically connected to the voltage detection module, and a first output terminal is electrically connected to a first input terminal of the comparator; A control circuit, wherein the input end of the control circuit is electrically connected to the second output end of the main control module and is used to receive a control signal of the main control module, and the output end of the control circuit is electrically connected to the enable end of the comparator.

6. The overvoltage protection circuit according to claim 5, wherein: The control circuit comprises: a second resistor, wherein a first end of the second resistor is electrically connected to a second output end of the main control module; a third resistor, a first end of the third resistor being electrically connected to the second end of the second resistor, and a second end of the third resistor being grounded; A first switch tube, wherein a gate of the first switch tube is electrically connected to the second end of the second resistor, and a source of the first switch tube is grounded; a second switch tube, wherein a gate of the second switch tube is electrically connected to a drain of the first switch tube, and a source of the second switch tube is grounded; a third switch tube, wherein a gate of the third switch tube is electrically connected to a drain of the second switch tube, a source of the third switch tube is electrically connected to the external device, and a drain of the third switch tube is electrically connected to a second input terminal of the comparator; A fourth resistor, wherein a first end of the fourth resistor is electrically connected to the pull-up power supply, and a second end of the fourth resistor is electrically connected to the gate of the second switch tube.

7. The overvoltage protection circuit according to claim 6, wherein: The control circuit further comprises: A fifth resistor, wherein a first end of the fifth resistor is electrically connected to the external device, and a second end of the fifth resistor is electrically connected to the drain of the second switch tube.

8. The overvoltage protection circuit according to claim 5, wherein: The charging circuit also includes: a sixth resistor, a first end of the sixth resistor being electrically connected to the second output end of the main control module; a seventh resistor, wherein a first end of the seventh resistor is electrically connected to the second end of the sixth resistor, and a second end of the seventh resistor is grounded; A fourth switch tube, wherein a gate of the fourth switch tube is electrically connected to the second end of the sixth resistor, a source of the fourth switch tube is grounded, and a drain of the fourth switch tube is electrically connected to the control end of the first control switch.

9. The overvoltage protection circuit according to claim 2, wherein: The first control switch is an N-type MOS tube or a P-type MOS tube.

10. The overvoltage protection circuit according to claim 1, wherein: The charge and discharge circuit also includes a discharge circuit: The signal acquisition module includes a current detection module for monitoring the flow direction of the current in the discharge circuit; The charge and discharge control module includes a discharge control module, which generates the control signal based on the flow direction of the current; A unidirectional conductive device, wherein a first end of the unidirectional conductive device is electrically connected to the external device; The overvoltage protection switch comprises a second control switch, a first end of the second control switch is electrically connected to the second end of the unidirectional conductive device, a second end is electrically connected to the load, and a control end is electrically connected to the output end of the discharge control module; In the case where current flows from the external device to the load, the control signal is a shutdown signal, and the second control switch is disconnected in response to the shutdown signal; or In a case where current flows from the load to the external device, the control signal is a connection signal, and the second control switch is closed in response to the connection signal.

11. The overvoltage protection circuit according to claim 10, wherein: The discharge control module comprises: a second diode, wherein an anode of the second diode is electrically connected to the load, and a cathode of the second diode is electrically connected to the external device; a third diode, wherein an anode of the third diode is electrically connected to the external device, and a cathode of the third diode is electrically connected to the load; A filter circuit, wherein a first input terminal of the filter circuit is electrically connected to the load, and a second input terminal of the filter circuit is electrically connected to the external device; An operational amplifier unit, wherein a positive electrode of the operational amplifier unit is electrically connected to the first input end of the filter circuit, a negative electrode is electrically connected to the second input end of the filter circuit, and an output end of the operational amplifier unit is electrically connected to the control end of the second control switch.

12. The overvoltage protection circuit according to claim 11, wherein: The filtering circuit comprises: a ninth resistor, wherein a first end of the ninth resistor is electrically connected to the load, and a second end of the ninth resistor is electrically connected to the positive electrode of the operational amplifier unit; a tenth resistor, wherein a first end of the tenth resistor is electrically connected to the external device, and a second end of the tenth resistor is electrically connected to the negative electrode of the operational amplifier unit; A first capacitor, wherein a first end of the first capacitor is electrically connected to the positive electrode of the operational amplifier unit, and a second end of the first capacitor is electrically connected to the negative electrode of the operational amplifier unit.

13. The overvoltage protection circuit according to claim 10, wherein: The unidirectional conductive device comprises a diode, an anode of the diode is electrically connected to the first end of the second control switch, and a cathode of the diode is electrically connected to the external device; Alternatively, the unidirectional conducting device comprises a MOS tube, a drain of the MOS tube being electrically connected to the first end of the second control switch, a source being electrically connected to the external device, and a gate being electrically connected to the output end of the discharge control module.

14. The overvoltage protection circuit according to claim 1, wherein: Also includes: A charge and discharge detection circuit, used to determine whether the external device is electrically connected to the charging circuit or the discharging circuit; A switching switch, wherein an input end of the switching switch is electrically connected to the external device, a first output end is electrically connected to the discharge circuit, and a second output end is electrically connected to the charging circuit.

15. An electronic device, comprising: load and overvoltage protection circuit, in the case of charging, the external device provides power to the load; In the case of discharge, the electronic device provides power to the external device; The overvoltage protection circuit comprises the overvoltage protection circuit described in any one of claims 1 to 14, wherein the overvoltage protection circuit generates a control signal according to the electrical signal in the charging and discharging circuit, and when the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first end and the second end of the overvoltage protection switch to disconnect the electrical connection between the external device and the load.

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