Over-voltage protection circuit and electronic device

Abstract

The present disclosure provides an over-voltage protection circuit, comprising: a signal collection module configured to collect an electrical signal in a charging and discharging circuit; a charging and discharging control module, wherein an input end of the charging and discharging control module is electrically connected to an output end of the signal collection module, and the charging and discharging control module generates a control signal on the basis of the electrical signal in the charging and discharging circuit; and an over-voltage protection switch, wherein a control end of the over-voltage protection switch is electrically connected to an output end of the charging and discharging control module, a first end of the over-voltage protection switch is electrically connected to an external device, a second end of the over-voltage protection switch is electrically connected to a load, and when the control signal is a turn-off signal, the over-voltage protection switch disconnects the electrical connection between the first end and the second end of the over-voltage protection switch so as to disconnect the electrical connection between the external device and the load. The present disclosure further provides an electronic device.

Description

Overvoltage protection circuit and electronic device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application CN 202411527653.5, filed on October 29, 2024, entitled “Overvoltage protection circuit and electronic device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the field of electronic technology, and in particular, to an overvoltage protection circuit and an electronic device. BACKGROUND

[0004] The overvoltage protection circuit is a circuit arranged in an electronic device to improve the service life of the electronic device. For example, in a charging device, arranging an overvoltage protection circuit can improve the service life of the charging device. In current charging devices, the voltage protection circuit needs to control the charging process by using a charging chip. However, the charging chip is expensive and the control logic is complex. SUMMARY

[0005] The present disclosure provides an overvoltage protection circuit and an electronic device.

[0006] The present disclosure provides an overvoltage protection circuit, comprising: a signal acquisition module, configured to acquire an electrical signal in a charging and discharging circuit; a charging and discharging control module, an input end of the charging and discharging control module being electrically connected to an output end of the signal acquisition module, and the charging and discharging control module being configured to generate a control signal according to the electrical signal in the charging and discharging circuit; and an overvoltage protection switch, a control end of the overvoltage protection switch being electrically connected to an output end of the charging and discharging control module, a first end of the overvoltage protection switch being electrically connected to an external device, and a second end of the overvoltage protection switch being electrically connected to a load, wherein, in a case where 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, so as to disconnect the electrical connection between the external device and the load.

[0007] The present disclosure also provides an electronic device, comprising: a load and an overvoltage protection circuit, in a case of charging, an external device providing electrical energy for the load; in a case of discharging, the load providing electrical energy for the external device, the overvoltage protection circuit being arranged between the external device and the load; the overvoltage protection circuit comprising an overvoltage protection circuit according to the present disclosure, the overvoltage protection circuit being configured to generate a control signal according to an electrical signal in a charging and discharging circuit, in a case where the control signal is an off signal, the overvoltage protection switch disconnecting 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 device and the load. BRIEF DESCRIPTION OF DRAWINGS

[0008] In the drawings of the embodiments of the present disclosure:

[0009] Fig. 1 is a block diagram of an overvoltage protection circuit according to an embodiment of the present disclosure;

[0010] Fig. 2 is a structural schematic diagram of an overvoltage protection circuit according to an embodiment of the present disclosure;

[0011] Fig. 3 is another structural schematic diagram of an overvoltage protection circuit according to an embodiment of the present disclosure;

[0012] Fig. 4 is a structural schematic diagram of a charging loop according to an embodiment of the present disclosure;

[0013] Fig. 5 is a circuit schematic diagram of a charging loop according to an embodiment of the present disclosure;

[0014] Fig. 6 is a structural schematic diagram of a discharging loop according to an embodiment of the present disclosure;

[0015] Fig. 7 is a structural schematic diagram of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0016] In order for those skilled in the art to better understand the technical solutions of the present disclosure, the embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0017] The embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, but the embodiments shown can be embodied in different forms and the present disclosure should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0018] The drawings of the embodiments of the present disclosure are used to provide further understanding of the embodiments of the present disclosure and form part of the specification, and are used to explain the present disclosure together with the detailed embodiments, and do not constitute a limitation of the present disclosure. The above and other features and advantages will become more apparent to those skilled in the art by referring to the detailed embodiments described below with reference to the drawings.

[0019] The present disclosure can be described with reference to plan views and / or sectional views by means of ideal schematic drawings of the present disclosure. Therefore, the example illustrations can be modified according to manufacturing techniques and / or tolerances.

[0020] The embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0021] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. The term "and / or" as used in this disclosure includes any and all combinations of one or more of the associated enumerated entries. The singular forms "a" and "the" as used in this disclosure are also intended to include the plural forms, unless the context clearly indicates otherwise. The terms "comprising," "made of," etc., as used in this disclosure specify the presence of the stated feature, integral, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0022] Unless otherwise specified, all terms used in this disclosure (including technical and scientific terms) have the same meaning as commonly understood by one 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 expressly so defined in this disclosure.

[0023] In some related technologies, overvoltage protection is achieved through charging chips in the charging and discharging circuit. However, charging chips are expensive and are integrated devices with multiple control logics built in, which makes the overvoltage protection logic complex. Therefore, it is necessary to develop an overvoltage protection circuit that is inexpensive and has simple control logic.

[0024] This disclosure provides an overvoltage protection circuit.

[0025] Figure 1 is a block diagram of an overvoltage protection circuit provided in an embodiment of this disclosure.

[0026] As shown in Figure 1, the overvoltage protection circuit according to an embodiment of the present disclosure includes: a signal acquisition module 10, a charge / discharge control module 20, and an overvoltage protection switch 30.

[0027] The signal acquisition module 10 is used to acquire electrical signals in the charging and discharging circuit, wherein the electrical signals include at least one of voltage signals and current signals.

[0028] The input terminal of the charge / discharge control module 20 is electrically connected to the output terminal of the signal acquisition module 10, and generates control signals based on the electrical signals in the charge / discharge circuit.

[0029] According to embodiments of this disclosure, the control signal includes a shutdown signal and a power-on signal. When the charging / discharging circuit experiences overvoltage, the charging / discharging control module 20 generates a shutdown signal; when the charging / discharging circuit does not experience overvoltage, the charging / discharging control module 20 generates a power-on signal.

[0030] The control terminal of the overvoltage protection switch 30 is electrically connected to the output terminal of the charge / discharge control module 20. The first terminal of the overvoltage protection switch 30 is electrically connected to the external device 3, and the second terminal is 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 and second terminals, thereby disconnecting the external device 3 from the load 4.

[0031] It should be noted that in the embodiments of this disclosure, charging is also referred to as internal charging, and discharging is also referred to as external discharging. For ease of description, this disclosure simply refers to them as charging and discharging. During charging, the external device 3 provides electrical energy to the load 4. At this time, the load 4 includes the battery and other circuits in the device besides the battery. During discharging, the load 4 supplies power to the external device 3. At this time, the load 4 includes the battery.

[0032] In this embodiment of the overvoltage protection circuit, the charging and discharging control module generates a control signal based on the electrical signal in the charging and discharging circuit acquired by the signal acquisition module. The control terminal of the overvoltage protection switch is electrically connected to the output terminal of the charging and discharging control module. The first terminal of the overvoltage protection switch is electrically connected to an external device, and the second terminal of the overvoltage protection switch is electrically connected to the load. When the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first and second terminals, thereby disconnecting the external device from the load. In other words, overvoltage protection is achieved through electronic devices, which is lower in cost than charging chips, has simpler control logic, and allows for adjustment of the electronic device parameters according to the needs of the overvoltage protection scenario, thus improving the flexibility of the overvoltage protection circuit.

[0033] In some embodiments, as shown in FIG2, the charging and discharging circuit according to the present disclosure includes a charging circuit 1, which is used to enable the external device 3 to charge the load 4. In this case, the load 4 includes a battery in the device and other circuits besides the battery.

[0034] Referring to Figure 2, in the charging circuit 1, the signal acquisition module 10 includes a voltage detection module 11, which is used to detect the voltage input by the external device 3 and output the detected voltage.

[0035] The voltage detection module 11 can be any module capable of measuring voltage, for example, the voltage detection module 11 includes a voltage measuring instrument.

[0036] The charge / discharge control module 20 includes a charging control module. The charging control module includes a comparator 12. A reference voltage is input to the first input terminal of the comparator 12, and the second input terminal of the comparator 12 is electrically connected to the output terminal of the voltage detection module 11. The output terminal of the comparator 12 outputs a control signal. The control signal includes a shutdown signal and a connection signal. When the detected voltage output by the voltage detection module 11 is higher than the reference voltage, the output terminal of the comparator 12 outputs a shutdown signal. When the detected voltage output by the voltage detection module 11 is lower than the reference voltage, the output terminal of the comparator 12 outputs a connection signal.

[0037] The overvoltage protection switch 30 includes a first control switch 13. The control terminal of the first control switch 13 is electrically connected to the output terminal of the comparator 12. The first terminal of the first control switch 13 is electrically connected to an external device, and the second terminal of the first control switch 13 is electrically connected to the load. The first control switch 13 controls the switching on and off of the first and second terminals according to the control signal output by the comparator 12.

[0038] When the detected voltage output by the voltage detection module 11 is higher than the reference voltage, the comparator 12 outputs a shutdown signal, and the first control switch 13 responds to the shutdown signal to disconnect the electrical connection between the external device 3 and the load 4.

[0039] According to the overvoltage protection circuit of this disclosure embodiment, in the charging circuit, a reference voltage is input to the first input terminal of the comparator, the second input terminal of the comparator 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 of the first control switch is electrically connected to an external device, and the second terminal of the first control switch is electrically connected to the load. When the detected voltage output by the voltage detection module is higher than the reference voltage, the comparator outputs a shutdown signal, and the first control switch responds to the shutdown signal to disconnect the external device from the load. This overvoltage protection circuit built with electronic components is lower in cost than charging chips, and the control logic is simple. The parameters of the electronic components can be adjusted according to the needs of the overvoltage protection scenario, thus improving the flexibility of the overvoltage protection circuit.

[0040] In some embodiments, the charging control module further includes a level adjustment module 14, which is serially connected between the output terminal of the comparator 12 and the control terminal of the first control switch 13. When the comparator 12 outputs a turn-off signal, the level adjustment module 14 makes the potential of the control terminal of the first control switch 13 reach the turn-off potential.

[0041] In this embodiment of the present disclosure, when the comparator 12 outputs a turn-off signal, the level adjustment module 14 can make the potential of the control terminal of the first control switch 13 quickly reach the turn-off potential.

[0042] 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 terminal of the comparator 12, and the anode of the first diode D1 is electrically connected to the control terminal of the first control switch 13. The first terminal of the first resistor R1 is electrically connected to the output terminal of the comparator 12, and the second terminal of the first resistor R1 is electrically connected to the control terminal of the first control switch 13.

[0043] The first resistor R1 is a current-limiting resistor, which can prevent excessive current from flowing into the first control switch 13.

[0044] In embodiments of this disclosure, the shutdown signal and the connection signal can be level signals. For example, the shutdown signal is a low-level signal and the connection signal is a high-level signal; or, the shutdown signal is a high-level signal and the connection signal is a low-level signal.

[0045] In some embodiments, the first control switch 13 may be a MOSFET. The levels of the turn-off signal and the connection signal can be determined according to the type of the first control switch 13. For example, when the first control switch 13 is an N-type MOSFET, the turn-off signal is a low-level signal and the connection signal is a high-level signal. When the first control switch 13 is a P-type MOSFET, the turn-off signal is a high-level signal and the connection signal is a low-level signal.

[0046] The following description uses an N-type MOSFET as an example of the first control switch 13. When the detected voltage output by the voltage detection module 11 is lower than the reference voltage, the comparator 12 outputs a high-level signal, the gate of the N-type MOSFET is at a high level, the N-type MOSFET is turned on, and the external device 3 charges the load 4. When the detected voltage output by the voltage detection module 11 is higher than the reference voltage, the output of the comparator 12 changes from a high-level signal to a low-level signal, the positive voltage of the first diode D1 is higher than the negative voltage, current flows from the positive terminal of the first diode D1 to the negative terminal, the gate level of the N-type MOSFET is quickly pulled low, the N-type MOSFET is quickly turned off, and overvoltage protection is provided for the load 4.

[0047] In some embodiments, the charging control module further includes a main control module 15 and a control circuit 17. The input terminal of the main control module 15 is electrically connected to the voltage detection module 11, and the first output terminal of the main control module 15 is electrically connected to the input terminal of the comparator 12.

[0048] In some embodiments, as shown in FIG3, the main control module package 15 includes a standard voltage setting circuit 151 and a main chip 152. The standard voltage setting circuit 151 is used to set a reference voltage, and the output terminal of the standard voltage setting circuit 151 is electrically connected to the first input terminal of the comparator 12. In this 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 the load and each device in the charging circuit.

[0049] When the charging circuit is in a charging state, the input terminal of the main chip 152 is electrically connected to the voltage detection module 11, and the first output terminal of the main chip 152 is electrically connected to the input terminal of the standard voltage setting circuit 151. In some embodiments, the main chip 152 can set a reference voltage according to the charging voltage, and the standard voltage setting circuit 151 sets a reference voltage according to the reference voltage determined by the main chip 152.

[0050] The input terminal of the control circuit 17 is electrically connected to the second output terminal of the main chip 152 to receive the control signal from the main chip 152. The output terminal of the control circuit 17 is electrically connected to the enable terminal of the comparator 12.

[0051] Figure 4 is a structural schematic diagram of the charging circuit provided in an embodiment of this disclosure, and Figure 5 is a circuit schematic diagram of the charging circuit provided in an embodiment of this disclosure.

[0052] As shown in Figures 4 and 5, the control circuit 17 includes: a second resistor R2, the first end of which is electrically connected to the second output terminal of the main chip 152; a third resistor R3, the first end of which is electrically connected to the second end of the second resistor R2, and the second end of the third resistor R3 is grounded; a first switch M1, the gate of which is electrically connected to the second end of the second resistor R2, and the source of which is grounded; a second switch M2, the gate of which is electrically connected to the drain of the first switch M1, and the source of which is grounded; a third switch M3, the gate of which is electrically connected to the drain of the second switch M2, the source of which is electrically connected to the external device 3, and the drain of which is electrically connected to the second input terminal of the comparator 12; and a fourth resistor R4, the first end of which is electrically connected to the pull-up power supply 18, and the second end of which is electrically connected to the gate of the second switch M2.

[0053] The first switch M1, the second switch M2, and the third switch M3 can be NMOS transistors or PMOS transistors. For example, the first switch M1 and the second switch M2 can be NMOS transistors, and the third switch M3 can be a PMOS transistor.

[0054] In this embodiment of the disclosure, the pull-up power supply 18 is the power supply of the peripheral device, and the voltage of the pull-up power supply 18 can be set as needed. This embodiment of the disclosure does not limit this.

[0055] The second resistor R2 and the third resistor R3 can keep the gate of the first switching transistor 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 switching transistor M1 at a low level, thus turning off the first switching transistor M1.

[0056] In some embodiments, the control circuit 17 further includes a fifth resistor R5, the first end of which is electrically connected to the external device 3, and the second end of which is electrically connected to the drain of the second switching transistor M2.

[0057] In some embodiments, the charging circuit further includes: a sixth resistor R6, the first end of which is electrically connected to the second output terminal of the main chip 152; a seventh resistor R7, the first end of which is electrically connected to the second end of the sixth resistor R6, and the second end of the seventh resistor R7 is grounded; and a fourth switch M4, the gate of which is electrically connected to the second end of the sixth resistor R6, the source of which is grounded, and the drain of which is electrically connected to the control terminal of the first control switch 13.

[0058] The on / off state of the first control switch 13 can be controlled by the sixth resistor R6, the seventh resistor R7, and the fourth switch M4. When manual control is required, the main chip 152 can send a main chip control signal to control the fourth switch M4, thereby controlling the on / off state of the first control switch 13.

[0059] In some embodiments, the fourth switch M4 can be an NMOS transistor or a PMOS transistor. This disclosure uses an NMOS transistor as an example for description.

[0060] The sixth resistor R6 and the seventh resistor R7 can keep the gate of the fourth switching transistor M4 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 seventh resistor R7 can also keep the gate of the fourth switching transistor M4 at a low level, thus turning off the fourth switching transistor M4.

[0061] Referring to Figures 4 and 5, external device 3 charges load 4 via USB interface 5. When main chip 152 detects the charging behavior of external device 3, its control signal is low, causing the gates of first switch M1 and fourth switch M4 to be low, thus turning off first switch M1 and fourth switch M4. Second switch M2 is turned on, and the gate of third switch M3 is low, turning on third switch M3. The power supply voltage input from external device 3 enters the second input terminal of comparator 12 through third switch M3 and is compared with a reference voltage. When the voltage of external device 3 is higher than the reference voltage, comparator 12 outputs a low-level signal, and the gate of fifth switch M5 is quickly pulled low through first diode D1, causing fifth switch M5 to be quickly turned off, thus quickly disconnecting the electrical connection between load 4 and external device 3, preventing overvoltage signals from entering load 4.

[0062] When the voltage of external device 3 returns to normal, that is, when the voltage of external device 3 is lower than the reference voltage, comparator 12 outputs a high-level signal, the gate of the fifth switch M5 returns to a high level, the fifth switch M5 is turned on again, and external device 3 charges load 4 through the fifth switch M5.

[0063] When the main chip 152 does not detect the charging behavior of the external device 3, the control signal of the main chip 152 is a high-level signal.

[0064] In some embodiments, the first switch M1, the second switch M2, the third switch M3, the fourth switch M4, and the fifth switch M5 can be electronic devices such as NMOS transistors or PMOS transistors that can control the on / off state of the circuit.

[0065] In some embodiments, the charging and discharging circuit according to this disclosure further includes a discharge circuit 2 for the load 4 to supply power to the external device 3, wherein the load 4 includes the device's battery.

[0066] Figure 6 is a schematic diagram of the discharge circuit provided in an embodiment of this disclosure.

[0067] Referring to Figures 2, 3, and 6, in the discharge circuit 2, the signal acquisition module 10 includes a current detection module for monitoring the current flow direction in the discharge circuit 2. In the discharge circuit 2, the current flow direction includes a first flow direction IN1 and a second flow direction IN2. The first flow direction IN1 is from the external device 3 to the load 4, and the second flow direction IN2 is from the load 4 to the external device 3.

[0068] The charge / discharge control module 20 includes: a discharge control module 21, which generates a control signal based on the direction of current flow; and a unidirectional conduction device 22, the first end of which is electrically connected to the external device 3. The unidirectional conduction device 22 can only allow current to flow from the load 4 to the external device 3, so as to ensure that the current flows to the load 4 during the discharge process.

[0069] The overvoltage protection switch 30 includes a second control switch 23. The first end of the second control switch 23 is electrically connected to the second end of the unidirectional conduction device 22. The second end of the second control switch 23 is electrically connected to the load 4. The control end of the second control switch 23 is electrically connected to the output end of the discharge control module 21.

[0070] When current flows from external device 3 to load 4, the control signal is a shutdown signal, and the second control switch 23 responds to the shutdown signal and disconnects, thereby disconnecting the electrical connection between external device 3 and load 4.

[0071] When current flows from load 4 to external device 3, the control signal is a connection signal, and the second control switch 23 closes in response to the connection signal, thereby electrically connecting external device 3 to load 4.

[0072] In some embodiments, the discharge control module 21 includes: a second diode D2, the anode of which is electrically connected to the load 4, and the cathode of which is electrically connected to the external device 3; a third diode D3, the anode of which is electrically connected to the external device 3, and the cathode of which is electrically connected to the load 4; a filter circuit 24, the first input terminal of which is electrically connected to the load 4, and simultaneously electrically connected to the anode of the second diode D2 and the cathode of the third diode D3, the second input terminal of which is electrically connected to the external device 3, and simultaneously electrically connected to the cathode of the second diode D2 and the anode of the third diode D3; and an operational amplifier unit 25, the anode of which is electrically connected to the first output terminal of the filter circuit 24, the cathode of which is electrically connected to the second output terminal of the filter circuit 24, and the output terminal of which is electrically connected to the control terminal of the second control switch 23.

[0073] In some embodiments, the filter circuit 24 includes: a ninth resistor R9, the first end of which is electrically connected to the load 4 and simultaneously electrically connected to the anode of the second diode D2 and the cathode of the third diode D3, and the second end of which is electrically connected to the anode of the operational amplifier unit 25; a tenth resistor R10, the first end of which is electrically connected to the external device 3 and simultaneously electrically connected to the cathode of the second diode D2 and the anode of the third diode D3, and the second end of which is electrically connected to the cathode of the operational amplifier unit 25; and a first capacitor C1, the first end of which is electrically connected to the anode of the operational amplifier unit 25 and simultaneously electrically connected to the second end of the ninth resistor R9, and the second end of which is electrically connected to the cathode of the operational amplifier unit 25 and simultaneously electrically connected to the second end of the tenth resistor R10.

[0074] Under normal circumstances, load 4 discharges to the outside through the second control switch 23 and the unidirectional conduction device 22. The discharge control module 21 monitors the current flow in the discharge circuit 2, and load 4 controls the operational amplifier unit 25 to start working through the control pin. When current flows to load 3 through the USB interface 5, the current is input to the discharge control module 21 through the first flow IN1. The first current passes through the third diode D3 and the ninth resistor R9 and enters the "+" terminal of the operational amplifier unit 25. The second current passes through the tenth resistor R10 and enters the "-" terminal of the operational amplifier unit 25. Therefore, the voltage of the "+" terminal is less than the voltage of the "-" terminal. The discharge control module 21 determines that the current is flowing from the external device 4 to the load 3. The operational amplifier unit 25 outputs a low level, and 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 load 4.

[0075] It should be noted that in the discharge circuit 2, the unidirectional conduction device 22 can work together with the discharge control module 21 to prevent the current of the external device 3 from flowing back into the load 4, and also to prevent the external device 3 from being damaged by overvoltage.

[0076] When current flows from load 4 to external device 3, the current flows through the second discharge control module 21 to IN2. The first current passes through the second diode D2 and the tenth resistor R10 to enter the "-" terminal of the operational amplifier unit 25, and the second current passes through the ninth resistor R9 to enter the "+" terminal of the operational amplifier unit 25. Therefore, the voltage of the "-" terminal is less than the voltage of the "+" terminal. The discharge control module 21 determines that the current is flowing from load 4 to external device 3. The operational amplifier unit 25 outputs a high level, and the second control switch 23 responds with a high level and closes. The current path between external device 3 and load 4 is connected, and load 4 supplies power to external device 3 normally.

[0077] In some embodiments, the unidirectional conducting device 22 includes a diode or a MOSFET, etc., that has a unidirectional conducting function. When the unidirectional conducting device 22 is a diode, the anode of the diode is electrically connected to the first terminal of the second control switch 23, and the cathode of the diode is electrically connected to the external device 3. When the unidirectional conducting device includes a MOSFET, the drain of the MOSFET is electrically connected to the first terminal of the second control switch 23, the source of the MOSFET is electrically connected to the external device 3, and the gate of the MOSFET is electrically connected to the output terminal of the discharge control module 21.

[0078] In some embodiments, the external device 3 charges the load 4 or the load 4 discharges the external device 3. During charging, the external device 3 and the load 4 are electrically connected through the charging circuit 1. During discharging, the external device 3 and the load 4 are electrically connected through the discharging circuit 2. The discharging circuit 2 and the charging circuit 1 are two independent circuits. The overvoltage protection circuit may also include a charge / discharge detection circuit and a switching switch.

[0079] Referring to Figures 2 and 3, the overvoltage protection circuit also includes a charge / discharge detection circuit 6 and a switching switch 7. The charge / discharge detection circuit 6 is used to determine whether the external device 3 is electrically connected to the charging circuit 1 or the discharging circuit 2. The input terminal of the switching switch 7 is electrically connected to the external device 3, the first output terminal of the switching switch 7 is electrically connected to the discharging circuit 2, and the second output terminal of the switching switch 7 is electrically connected to the charging circuit 1.

[0080] In some embodiments, charging or discharging is determined by negotiation between the charge / discharge detection circuit 6 and the load 4. When the negotiation is that the external device 3 is internally charging the load 4, the charge / discharge detection circuit 6 switches the switch 7 to the charging circuit 1; when the negotiation is that the load 4 is externally discharging the external device 3, the charge / discharge detection circuit 6 switches the switch 7 to the discharging circuit 2.

[0081] The overvoltage protection circuit provided in this application can be applied not only to electronic products that only require a charging circuit, such as mobile routers (or mobile hotspots, Mobile WIFI, MIFI) and mobile phones, but also to charging and discharging electronic products such as portable power banks.

[0082] It should be noted that, in the embodiments of this disclosure, the charging and discharging circuit may include only a charging circuit or a discharging circuit, or the charging and discharging circuit may include both a charging circuit and a discharging circuit. The overvoltage protection circuit provides overvoltage protection for the charging circuit during charging and overvoltage protection for the discharging circuit during discharging.

[0083] This disclosure provides an electronic device.

[0084] Figure 7 is a schematic diagram of the structure of the electronic device provided in the embodiments of this disclosure.

[0085] As shown in FIG7, the electronic device according to an embodiment of the present disclosure includes a load 61 and an overvoltage protection circuit 62. When charging, the external device 63 provides power to the load 61; when discharging, the electronic device provides power to the external device 63.

[0086] It should be noted that, during charging, load 61 includes the battery in the electronic device and other circuits besides the battery. External device 63 charges the battery in the electronic device and also provides power to the other circuits besides the battery. During discharging, the battery in the electronic device can provide power to external device 63.

[0087] The overvoltage protection circuit 62 can be the overvoltage protection circuit provided in the embodiments of this disclosure, and the specific structure and control logic will not be described in detail here.

[0088] When the overvoltage protection circuit 62 detects that the voltage input to the external device 63 is higher than the preset reference voltage, it disconnects the electrical connection between the external device 63 and the load 61.

[0089] In the electronic device of this embodiment, the charging and discharging control module generates a control signal based on the electrical signal in the charging and discharging circuit acquired by the signal acquisition module. The control terminal of the overvoltage protection switch is electrically connected to the output terminal of the charging and discharging control module. The first terminal of the overvoltage protection switch is electrically connected to an external device, and the second terminal of the overvoltage protection switch is electrically connected to the load. When the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between the first and second terminals, thereby disconnecting the external device from the load. In other words, overvoltage protection is achieved through electronic devices. This is lower in cost than charging chips, reducing the cost of the electronic device. Moreover, the control logic is simple, simplifying the control logic of the electronic device. Furthermore, the parameters of the electronic devices can be adjusted according to the needs of the overvoltage protection scenario, improving the flexibility of the overvoltage protection circuit and expanding the application range of the electronic device.

[0090] This disclosure has disclosed exemplary embodiments, and although specific terminology has been used, it is for general illustrative purposes only and should not be construed as limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. An overvoltage protection circuit, comprising: The signal acquisition module is used to acquire electrical signals in the charging and discharging circuit. A charge / discharge control module, wherein the input terminal of the charge / discharge control module is electrically connected to the output terminal of the signal acquisition module, and the charge / discharge control module generates a control signal based on the electrical signal in the charge / discharge circuit; An overvoltage protection switch is included, with its control terminal electrically connected to the output terminal of the charge / discharge control module, its first terminal electrically connected to an external device, and its second terminal electrically connected to the load. When the control signal is a shutdown signal, the overvoltage protection switch disconnects the electrical connection between its first and second terminals to disconnect the external device from the load.

2. The overvoltage protection circuit according to claim 1, wherein, The charging and discharging circuit includes 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 detected voltage. The charge / discharge control module includes a charging control module, which includes a comparator. The first input terminal of the comparator receives a reference voltage, and the second input terminal of the comparator is electrically connected to the output terminal of the voltage detection module. The output terminal of the comparator outputs the control signal. The overvoltage protection switch includes a first control switch, the control terminal of the first control switch is electrically connected to the output terminal of the comparator, the first terminal of the first control switch is electrically connected to the external device, and the second terminal of the first control switch is electrically connected to the load. When the detected voltage output by the voltage detection module is higher than the reference voltage, the comparator outputs a shutdown signal, and the first control switch responds to the shutdown signal to disconnect the external device from the load.

3. The overvoltage protection circuit according to claim 2, wherein, The charging control module further includes a level adjustment module, which is connected in series between the output terminal of the comparator and the control terminal of the first control switch. When the comparator outputs a turn-off signal, the level adjustment module makes the potential of the control terminal of the first control switch reach the turn-off potential.

4. The overvoltage protection circuit according to claim 3, wherein, The level adjustment module includes: The first diode D1 has its cathode electrically connected to the output terminal of the comparator, and its anode electrically connected to the control terminal of the first control switch. A first resistor, the first end of which is electrically connected to the output terminal of the comparator, and the second end of which is electrically connected to the control terminal of the first control switch.

5. The overvoltage protection circuit according to claim 2, wherein, The charging control module also includes: The main control module has its input terminal electrically connected to the voltage detection module, and its first output terminal electrically connected to the first input terminal of the comparator. The control circuit has its input terminal electrically connected to the second output terminal of the main control module, and is used to receive the control signal from the main control module. The output terminal of the control circuit is electrically connected to the enable terminal of the comparator.

6. The overvoltage protection circuit according to claim 5, wherein, The control circuit includes: The second resistor has its first end electrically connected to the second output terminal of the main control module. The third resistor has its first end electrically connected to the second end of the second resistor, and its second end is grounded. The first switching transistor has its gate electrically connected to the second terminal of the second resistor, and its source is grounded. The second switching transistor has its gate electrically connected to the drain of the first switching transistor, and its source is grounded. The third switching transistor has its gate electrically connected to the drain of the second switching transistor, its source electrically connected to the external device, and its drain electrically connected to the second input terminal of the comparator. The fourth resistor has its first end electrically connected to the pull-up power supply and its second end electrically connected to the gate of the second switching transistor.

7. The overvoltage protection circuit according to claim 6, wherein, The control circuit also includes: The fifth resistor has its first end electrically connected to the external device and its second end electrically connected to the drain of the second switching transistor.

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

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

10. The overvoltage protection circuit according to claim 1 or 2, wherein, The charging and discharging circuit includes a discharging circuit. The signal acquisition module includes a current detection module for monitoring the current flow direction in the discharge circuit; The charge / discharge control module includes: A discharge control module that generates the control signal based on the direction of current flow; A unidirectional conducting device, wherein a first end of the unidirectional conducting device is electrically connected to the external device; The overvoltage protection switch includes a second control switch. The first terminal of the second control switch is electrically connected to the second terminal of the unidirectional conducting device, the second terminal of the second control switch is electrically connected to the load, and the control terminal of the second control switch is electrically connected to the output terminal of the discharge control module. Wherein, when current flows from the external device to the load, the control signal is a shutdown signal, and the second control switch disconnects in response to the shutdown signal; When current flows from the load to the external device, the control signal is a connection signal, and the second control switch closes in response to the connection signal.

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

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

13. The overvoltage protection circuit according to claim 10, wherein, The unidirectional conduction device includes a diode, the anode of which is electrically connected to the first terminal of the second control switch, and the cathode of which is electrically connected to the external device; or The unidirectional conduction device includes a MOS transistor, the drain of which is electrically connected to the first terminal of the second control switch, the source of which is electrically connected to the external device, and the gate of which is electrically connected to the output terminal of the discharge control module.

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

15. An electronic device comprising a load and an overvoltage protection circuit, wherein, in the case of charging, an external device provides electrical energy to the load; and in the case of discharging, the electronic device provides electrical energy to the external device; The overvoltage protection circuit includes the overvoltage protection circuit according to any one of claims 1-14.

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