Charging protection circuit, circuit board and device

Abstract

The embodiment of the utility model provides a charging protection circuit, a circuit board and a device, and the circuit comprises a sampling circuit which is connected with a charging interface and is used for sampling a charging voltage inputted from the charging interface and outputting a sampling signal, and the charging voltage is used for charging a charging circuit; the control circuit comprises a control module, and the control module is connected with the sampling circuit and used for outputting a stop signal for controlling the charging circuit to stop charging according to the sampling signal; and the voltage stabilizing circuit is respectively connected with the charging interface and the control module and is used for outputting power supply voltage to the control module according to the charging voltage. The charging interface is connected with the control module through the voltage stabilizing module, the control module can obtain the power supply voltage under the condition that the charging voltage is higher than the power supply voltage, and the power supply voltage output by the voltage stabilizing module is kept in a certain voltage range due to the fact that the voltage stabilizing module has a certain voltage stabilizing range. Therefore, the influence of the power supply voltage with an over-high voltage value on the control module can be reduced.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to a charging protection circuit, a circuit board and a device. Background Art

[0002] At present, there are more and more products with lithium batteries on the market, and different products with lithium batteries have different charging voltage standards. For some reasons, these products with lithium batteries use the same type of charging port, which allows the chargers of these products to be connected to non-corresponding products.

[0003] For some products with lithium batteries, there are usually charging protection circuits inside, which will match the chargers configured for the products. These charging protection circuits usually include chips for voltage comparison. When these products are connected to chargers that can output higher than their own standard charging voltage, the excessively high charging voltage will affect the normal operation of the chip, thus affecting the normal operation of the charging protection circuit, because the charger does not match the charging protection circuit. Utility Model Content

[0004] In view of the deficiencies in the prior art, the present application proposes a charging protection circuit, a circuit board and a device, aiming to improve the applicability of the charging protection circuit.

[0005] To achieve the above-mentioned object, the first aspect of the present application provides a charging protection circuit, the charging protection circuit comprising:

[0006] a sampling circuit, connected to a charging interface, for sampling a charging voltage input from the charging interface and outputting a sampling signal, wherein the charging voltage is used to charge the charging circuit;

[0007] A control circuit, comprising a control module, wherein the control module is connected to the sampling circuit, and the control module is used to output a stop signal according to the sampling signal, wherein the stop signal is used to control the charging circuit to stop charging;

[0008] A voltage stabilizing circuit is connected to the charging interface and the control module respectively, and is used for outputting a regulated supply voltage to the control module according to the charging voltage.

[0009] In some possible embodiments of the present application, the control circuit includes:

[0010] The switch module is connected to the charging interface, the control module and the charging circuit respectively, and the switch module is used to stop transmitting the charging voltage to the charging circuit when receiving the stop signal.

[0011] In some possible embodiments of the present application, the voltage stabilizing circuit includes:

[0012] A step-down module is connected to the charging interface and the control module respectively, and is used to step down the charging voltage to output the supply voltage to the control module.

[0013] In some possible embodiments of the present application, the sampling circuit is connected to multiple charging interfaces, there are multiple step-down modules, multiple step-down modules and multiple charging interfaces are connected one-to-one, and multiple step-down modules are connected to the control module.

[0014] In some possible embodiments of the present application, the switch module includes:

[0015] a first switch unit, connected to the charging interface and the charging circuit respectively, and the first switch unit is used to stop transmitting the charging voltage to the charging circuit in a cut-off state;

[0016] The second switch unit is respectively connected to the charging interface, the control module and the first switch unit, and the second switch unit is used to output a cut-off signal to the first switch unit according to the charging voltage when receiving the stop signal, wherein the cut-off signal is used to make the first switch unit enter a cut-off state.

[0017] In some possible embodiments of the present application, the second switch unit includes:

[0018] a first switch device, wherein a first end of the first switch device is connected to the first switch unit, a second end of the first switch device is connected to the control module, and the first switch device is configured to enter a conducting state when receiving the stop signal;

[0019] A pull-up resistor is connected to the charging interface and the first switch unit respectively, and is connected in parallel with the first end of the first switch device relative to the first switch unit. The pull-up resistor is used to output the cut-off signal to the first switch unit according to the charging voltage when the first switch device enters the on state.

[0020] In some possible embodiments of the present application, the charging protection circuit further includes:

[0021] A safety circuit is used to connect at least one of the sampling circuit, the control circuit and the voltage stabilizing circuit to the charging interface.

[0022] In some possible embodiments of the present application, the charging protection circuit further includes:

[0023] The isolation circuit is used to connect the sampling circuit and the control module.

[0024] To achieve the above-mentioned purpose, the second aspect of the present application provides a circuit board, and the circuit board includes the charging protection circuit as described in the first aspect above.

[0025] To achieve the above objective, a third aspect of the present application provides a device, which includes the circuit board as described in the second aspect.

[0026] The embodiment of the present application provides a charging protection circuit, a circuit board and a device, wherein the charging protection circuit includes a sampling circuit, connected to a charging interface, for sampling a charging voltage input from the charging interface and outputting a sampling signal, wherein the charging voltage is used to charge the charging circuit; a control circuit, including a control module, the control module is connected to the sampling circuit, the control module is used to output a stop signal according to the sampling signal, wherein the stop signal is used to control the charging circuit to stop charging; a voltage stabilizing circuit, connected to the charging interface and the control module respectively, the voltage stabilizing circuit is used to output a supply voltage to the control module according to the charging voltage. By connecting the charging interface with the control module using a voltage stabilizing module, the control module can obtain a supply voltage when the charging voltage is higher than the supply voltage, and since the voltage stabilizing module has a certain voltage stabilizing range, the supply voltage output by the voltage stabilizing module is also kept in a certain voltage range, thereby reducing the influence of the supply voltage of the overly high voltage value on the control module, thereby enabling the charging protection circuit to still achieve normal charging protection function under the condition of a higher charging voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a circuit diagram of a charging protection circuit provided by an embodiment of the present application;

[0028] Figure 2 It is a circuit diagram of a charging protection circuit provided in another embodiment of the present application.

[0029] Reference numerals:

[0030] Charging protection circuit 1, sampling circuit 11, control circuit 12, control module 121, switch module 122, first switch unit 123, second switch unit 124, first switch device 125, pull-up resistor 126, voltage stabilizing circuit 13, buck module 131, insurance circuit 14, charging interface 2, charging circuit 3. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0033] At present, there are more and more products with lithium batteries on the market, and different products with lithium batteries have different charging voltage standards. For some reasons, these products with lithium batteries use the same type of charging port, which allows the chargers of these products to be connected to non-corresponding products.

[0034] For some products with lithium batteries, there are usually charging protection circuits inside, which will match the chargers configured for the products. These charging protection circuits usually include chips for voltage comparison. When these products are connected to chargers that can output higher than their own standard charging voltage, the excessively high charging voltage will affect the normal operation of the chip, thus affecting the normal operation of the charging protection circuit, because the charger does not match the charging protection circuit.

[0035] Based on this, the embodiments of the present application provide a charging protection circuit, a circuit board and a device, aiming to improve the applicability of the charging protection circuit.

[0036] Before describing the embodiments of the present application, for the convenience of description, definitions are made here to define the pins of all capacitors, resistors, diodes, switching devices and other devices that appear in the present application. From left to right of the circuit in the accompanying drawings, for devices with pins distributed in the horizontal direction, the first end is the left pin of the device, and the second end is the right pin of the device; for devices with pins distributed in the vertical direction, the first end is the upper pin of the device, and the second end is the lower pin of the device; for devices with pins distributed in all directions, the first end is the upper left pin of the device, and the second end is the next pin of the first end along the clockwise direction of the device.

[0037] The charging protection circuit, circuit board and device provided in the embodiments of the present application are specifically described through the following embodiments. First, the charging protection circuit in the embodiments of the present application is described.

[0038] Reference Figure 1 As shown, in this embodiment, the charging protection circuit 1 may include but is not limited to a sampling circuit 11 , a control circuit 12 and a voltage stabilizing circuit 13 .

[0039] The sampling circuit 11 is connected to the charging interface 2 , and can be used to sample the charging voltage input from the charging interface 2 and output a sampling signal. The charging voltage can be used to charge the charging circuit 3 .

[0040] The control circuit 12 may include but is not limited to a control module 121, which is connected to the sampling circuit 11 and may be used to output a stop signal according to the sampling signal, wherein the stop signal may be used to control the charging circuit 3 to stop charging.

[0041] The voltage stabilizing circuit 13 is connected to the charging interface 2 and the control module 121 respectively. The voltage stabilizing circuit 13 can be used, but is not limited to, to control the output of the supply voltage to the control module 121 according to the charging voltage. The supply voltage is lower than the voltage value of the charging voltage, that is, the voltage stabilizing circuit 13 can actually achieve the function of step-down and voltage stabilization.

[0042] Specifically, when the charging cable is inserted into the charging interface 2 for charging, the charging cable can transmit the charging voltage to the charging interface 2, and the charging voltage will first be transmitted to the voltage stabilizing circuit 13 and the sampling circuit 11. The sampling circuit 11 can sample the charging voltage and output the sampling signal to the outside. At this time, the control module 121 cannot be powered on because the power supply voltage has not been obtained. Therefore, the control module 121 cannot receive the sampling signal output by the sampling circuit 11. After obtaining the charging voltage, the voltage stabilizing circuit 13 performs a certain degree of voltage reduction and voltage stabilization on the charging voltage. The voltage stabilizing ability of the voltage stabilizing circuit 13 is limited. Therefore, the voltage value of the power supply voltage output by the voltage stabilizing circuit 13 will be within a certain range, so that the control module 121 will not obtain a voltage outside its own voltage tolerance range, so that the control module 121 can work normally under a higher charging voltage. The power supply voltage output by the voltage stabilizing circuit 13 will be transmitted to the control module 121, and the control module 121 can be powered on and run after obtaining the power supply voltage. At this time, since the sampling circuit 11 is connected to the charging interface 2 and the control module 121 respectively, the control module 121 can receive the sampling signal output by the sampling circuit 11. It should be noted that when the charging voltage exceeds the limit step-down voltage regulation capability of the voltage regulator circuit 13, the voltage regulator circuit 13 will be damaged by the charging voltage.

[0043] After receiving the sampling signal, the control module 121 can compare the charging voltage with the preset safe charging voltage according to the sampling signal; when the charging voltage is greater than the preset safe charging voltage, the control module 121 can output a stop signal to the charging circuit 3 to stop the charging of the charging circuit 3; when the charging voltage is less than or equal to the preset safe charging voltage, the control module 121 will not output a stop signal, so that the charging circuit 3 can start charging or resume charging. The charging protection circuit 1 can control the charging process of the charging circuit by sampling the charging voltage, thereby reducing the impact of the charging voltage greater than the preset safe charging voltage on the charging circuit, and further reducing the damage to the rechargeable battery and the charging circuit due to overvoltage charging. Among them, the charging circuit 3 can control charging through a charging signal, and the control module 121 can also be used to output a charging signal. When the charging voltage is less than or equal to the preset safe charging voltage, the control module 121 outputs a charging signal. When the charging voltage is greater than the preset safe charging voltage, the control module 121 outputs a stop signal. The charging circuit 3 may also not control charging through a charging signal. When the charging voltage is less than or equal to the preset safe charging voltage, the control module 121 does not output a signal to enable the charging circuit 3 to charge. When the charging voltage is greater than the preset safe charging voltage, the control module 121 outputs a stop signal to enable the charging circuit 3 to stop charging, etc., which is not specifically limited here.

[0044] The embodiment of the present application uses a voltage stabilizing module to connect the charging interface with the control module, so that the control module can obtain the supply voltage when the charging voltage is higher than the supply voltage. Since the voltage stabilizing module has a certain voltage stabilizing range, the supply voltage output by the voltage stabilizing module is also maintained in a certain voltage range. Therefore, the influence of the supply voltage with excessively high voltage value on the control module can be reduced, and the charging protection circuit can still achieve normal charging protection function under the condition of higher charging voltage.

[0045] In one embodiment, the charging interface 2 can be various, for example, the charging interface 2 can be a DC 3.5mm interface, a type C interface, a Micro-USB interface, etc., which are not specifically limited here. In addition, the preset safe charging voltage can be 5V, 6V, 10V, 12V, 15V, etc., which are not specifically limited here.

[0046] In one embodiment, the sampling circuit 11 may be various in specific, and may be the following embodiments or other embodiments, which are not specifically limited here.

[0047] For example, Figure 1 The sampling circuit 11 shown in FIG. 1 is a resistor voltage divider circuit, including a first voltage divider resistor (in Figure 1 R1 in the figure) and the second voltage divider resistor (in Figure 1The first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, and the series connection point of the first voltage-dividing resistor and the second voltage-dividing resistor is connected to the control module 121. The sampling circuit 11 can perform voltage-dividing sampling through the two voltage-dividing resistors, thereby outputting a sampling signal.

[0048] For another example, the sampling circuit 11 is an operational amplifier sampling circuit, which may include a resistor voltage divider circuit and an operational amplifier, so that the charging voltage can be accurately sampled, thereby improving the control accuracy of the charging process of the charging circuit.

[0049] In one embodiment, the control module 121 may be a microcontroller unit (MCU) such as STM32F103RCT6, PIC18-Q20, or may include the above MCU and some external circuits, or may be a comparison circuit composed of an operational amplifier, etc., which is not specifically limited here. In addition, the control module 121 may also output a charging signal, which is used to control the charging circuit 3 to start or resume charging.

[0050] In one embodiment, for the charging circuit 3, when the enabling terminal is set for the charging circuit 3, the control module 121 can be directly connected to the enabling terminal of the charging circuit 3, so that the stop signal output by the control module 121 can directly act on the charging circuit 3, thereby enabling the charging circuit 3 to stop charging.

[0051] In one embodiment, the control circuit 12 may also include but not limited to a switch module 122, the switch module 122 is respectively connected to the charging interface 2, the control module 121 and the charging circuit 3, the switch module 122 may be but not limited to stop transmitting the charging voltage to the charging circuit 3 when a stop signal is received, and the switch module 122 may also be used to start or resume transmitting the charging voltage to the charging circuit 3 when a stop signal is not received. Among them, the switch module 122 may be single-signal controlled, the control module 121 only outputs a stop signal, and when the switch module 122 does not receive a stop signal, the charging circuit 3 may be charged; the switch module 122 may also be multi-signal controlled, the control module 121 may output a stop signal and a charging signal, and when the switch module 122 receives a charging signal, the charging circuit 3 may be charged, etc. No specific limitation is made here.

[0052] For example, when the charging circuit 3 is provided with an enable terminal, the switch module 122 and the charging circuit 3 itself can form a double charging protection, thereby reducing the damage of the over-voltage charging point voltage to the charging circuit 3 and the control module 121.

[0053] For another example, the switch module 122 may be a switch device, or may include a switch device and its external circuit, or may include a plurality of switch units, etc., which is not specifically limited here.

[0054] In one embodiment, Figure 1 The switch module 122 shown in the figure may include, but is not limited to, a first switch unit 123 and a second switch unit 124. The first switch unit 123 is connected to the charging interface 2 and the charging circuit 3, respectively, and the first switch unit 123 can be used to stop transmitting the charging voltage to the charging circuit 3 in the cut-off state. The second switch unit 124 is connected to the charging interface 2, the control module 121 and the first switch unit 123, respectively, and the second switch unit 124 can be used to output a cut-off signal to the first switch unit 123 according to the charging voltage when a stop signal is received, wherein the cut-off signal can be used to put the first switch unit 123 into the cut-off state.

[0055] Specifically, when the second switch unit 124 does not receive the stop signal, the second switch unit 124 is turned on, so that the second switch unit 124 cannot output the cut-off signal. At this time, the first switch unit 123 is in the on state, and the first switch unit 123 can transmit the charging voltage transmitted by the charging interface 2 to the charging circuit 3 through itself. When the second switch unit 124 receives the stop signal, the second switch unit 124 will be cut off immediately. Due to entering the cut-off state, the second switch unit 124 will output a cut-off signal, and this cut-off signal can make the first switch unit 123 enter the cut-off state. After the first switch unit 123 enters the cut-off state, the charging voltage cannot be transmitted from the first switch unit 123 to the charging circuit 3, so that the charging of the charging circuit 3 can be stopped. Among them, the cut-off state of the first switch unit 123 refers to the state in which the first switch unit 123 cuts off the transmission path between the charging interface 2 and the charging circuit 3.

[0056] In one embodiment, the first switch unit 123 and the second switch unit 124 may be a switch device, or may be other circuits with a switch function, which are not specifically limited here. When the first switch unit 123 and the second switch unit 124 are switch devices or include switch devices, the switch devices may be electronic switch diodes, transistors, MOS tubes, etc., which are not specifically limited here.

[0057] In one embodiment, Figure 1The second switch unit 124 shown in the figure may include but is not limited to a first switch device 125 and a pull-up resistor 126. The first end of the first switch device 125 is connected to the first switch unit 123, and the second end of the first switch device 125 is connected to the control module 121. The first switch device 125 may be, but is not limited to, used to enter the on state when a stop signal is received. The pull-up resistor 126 is connected to the charging interface 2 and the first switch unit 123, respectively, and is connected in parallel with the first end of the first switch device 125 relative to the first switch unit 123. The pull-up resistor 126 may be, but is not limited to, used to output a cut-off signal to the first switch unit 123 according to the charging voltage when the first switch device 125 enters the on state.

[0058] Specifically, when the control module 121 has not output a stop signal, the first switch device 125 is in a cut-off state. At this time, the pull-up resistor 126 pulls up the voltage according to the charging voltage, so that the first switch unit 123 can be turned on; when the control module 121 outputs a stop signal, the first switch device 125 enters a conduction state. At this time, since the third end of the first switch device 125 is grounded, the charging voltage is directed to the ground terminal through the first switch device 125. At this time, the potential at the second end of the pull-up resistor 126 will drop to 0, so that the pull-up resistor 126 can output a cut-off signal to the first switch unit 123 according to the process that the charging voltage is directed to the ground terminal, so that the first switch unit 123 can be turned off, and then the charging circuit 3 can stop obtaining the charging voltage from the charging interface 2.

[0059] In one embodiment, Figure 1 The voltage stabilizing circuit 13 shown in the figure may include, but is not limited to, a step-down module 131, which is respectively connected to the charging interface 2 and the control module 121. The step-down module 131 may be used, but is not limited to, to step down the charging voltage to output a supply voltage to the control module 121.

[0060] Specifically, since the control module 121 includes an MCU, the control module 121 requires a certain working voltage to operate, and the working voltage of the MCU is in a certain voltage range. When the voltage applied to the control module 121 is greater than the maximum voltage in this voltage range, the voltage applied to the control module 121 will damage the control module 121, thereby causing the charging protection circuit 1 to fail. Moreover, the voltage source of the control module 121 is the charging voltage, which must be greater than the power supply voltage. Therefore, the step-down module 131 is required to step down the charging voltage transmitted by the charging interface 2 to the power supply voltage, so that the control module 121 can work normally. Among them, the step-down module 131 can be a step-down circuit, or a step-down integrated circuit (IC), etc., which is not specifically limited here.

[0061] In one embodiment, the buck module 131 may include a buck IC and multiple external circuits, and a plurality of charging interfaces 2 may be provided, and the plurality of charging interfaces 2 correspond one-to-one to the plurality of external circuits, each charging interface 2 corresponds to a different charging voltage, and the corresponding external circuit may divide the charging voltage, so that the voltage value input to the buck IC is within the buck capability range of the buck IC, and the buck IC can stably output the supply voltage to the control module 121 according to the charging voltage, thereby reducing the situation where the charging voltage damages the buck IC.

[0062] In one embodiment, there may be multiple charging interfaces 2 connected to the sampling circuit 11, and there may also be multiple step-down modules 131. Multiple step-down modules 131 are connected to multiple charging interfaces 2 in a one-to-one correspondence, and multiple step-down modules 131 are connected to the control module 121. Specifically, each step-down module 131 corresponds to a voltage step-down range. When charging, the user can select one of the multiple charging interfaces 2 to insert the charging line, so that the voltage can be stepped down by the step-down module 131 corresponding to the charging interface 2. For example, the step-down range corresponding to the step-down module 131 corresponding to one charging interface 2 is 10-12V, and the step-down range corresponding to the step-down module 131 corresponding to another charging interface 2 is 5-6V. The user can select the charging interface 2 into which the charging line is inserted according to the power supply used by the user.

[0063] Reference Figure 2 As shown, in one embodiment, the charging protection circuit 1 may further include a safety circuit 14, which may be used to connect at least one of the sampling circuit 11, the control circuit 12, and the voltage stabilizing circuit 13 to the charging interface 2, so that when an overcurrent or overvoltage occurs at the charging interface 2, the safety circuit 14 may perform a safety action, thereby improving the working stability and service life of the charging circuit 3 and / or the charging protection circuit 1. The safety circuit 14 may be a fuse, a varistor (the resistance value changes with the voltage), etc., which is not specifically limited here.

[0064] In one embodiment, the charging protection circuit 1 may further include an isolation circuit (not shown in either figure), which may be used to connect the sampling circuit 11 and the control module 121. When the charging voltage sampled by the sampling circuit 11 is too large, the voltage value of the sampling signal output by the sampling circuit 11 will also be too large. At this time, if the sampling signal with an excessively large voltage value is input into the control module 121, the control module 121 may be damaged. Therefore, it is necessary to add an isolation circuit as a protection measure between the sampling circuit 11 and the control module 121. Among them, the isolation circuit can be a voltage limiting circuit, or an optocoupler (the degree of light emission inside the optocoupler is limited. In the case of overvoltage, the voltage value of the sampling signal output by the optocoupler is a certain value), etc., which is not specifically limited here.

[0065] In order to achieve the above objectives, an embodiment of the present application further provides a circuit board, which may include but is not limited to the charging protection circuit provided in the above embodiment.

[0066] In order to achieve the above objectives, an embodiment of the present application further provides a device, which may include but is not limited to the circuit board provided in the above embodiment.

[0067] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the situation where A exists alone, A and B exist at the same time, and B exists alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b and c can mean: a exists alone, b exists alone, c exists alone, a and b exist at the same time, a and c exist at the same time, b and c exist at the same time, or a, b and c exist at the same time, wherein a, b, c can be single or multiple.

[0069] In the embodiments of the present application, "indication" may include direct indication and indirect indication, and may also include explicit indication and implicit indication. The information indicated by a certain information is called information to be indicated. In the specific implementation process, there may be many ways to indicate the information to be indicated, such as but not limited to, the information to be indicated may be directly indicated, such as indicating the information to be indicated itself or the index of the information to be indicated. The information to be indicated may also be indirectly indicated by indicating other information, wherein the other information has an association relationship with the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information may also be achieved by means of the arrangement order of each information agreed in advance (for example, specified by the protocol), thereby reducing the indication overhead to a certain extent.

[0070] In the embodiments of the present application, each term and English abbreviation is provided for the convenience of description and shall not constitute any limitation to the present application. The present application does not exclude the possibility of defining other terms that can achieve the same or similar functions in existing or future protocols.

[0071] In the embodiments of the present application, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0072] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A charging protection circuit, characterized in that: The charging protection circuit comprises: a sampling circuit, connected to a charging interface, for sampling a charging voltage input from the charging interface and outputting a sampling signal, wherein the charging voltage is used to charge the charging circuit; A control circuit, comprising a control module, wherein the control module is connected to the sampling circuit, and the control module is used to output a stop signal according to the sampling signal, wherein the stop signal is used to control the charging circuit to stop charging; A voltage stabilizing circuit, connected to the charging interface and the control module respectively, and configured to output a regulated supply voltage to the control module according to the charging voltage; in: The control circuit comprises: a switch module, connected to the charging interface, the control module and the charging circuit respectively, and the switch module is used to stop transmitting the charging voltage to the charging circuit when receiving the stop signal; The switch module includes: a first switch unit, connected to the charging interface and the charging circuit respectively, and the first switch unit is used to stop transmitting the charging voltage to the charging circuit in a cut-off state; a second switch unit, connected to the charging interface, the control module and the first switch unit respectively, and the second switch unit is used to output a cut-off signal to the first switch unit according to the charging voltage when receiving the stop signal, wherein the cut-off signal is used to make the first switch unit enter a cut-off state; The second switch unit includes: a first switch device, a first end of the first switch device is connected to the first switch unit, a second end of the first switch device is connected to the control module, and the first switch device is used to enter a conducting state when receiving the stop signal; a pull-up resistor, which is respectively connected to the charging interface and the first switch unit, and is connected in parallel with the first end of the first switch device relative to the first switch unit, and the pull-up resistor is used to output the cut-off signal to the first switch unit according to the charging voltage when the first switch device enters the conducting state; The voltage stabilizing circuit includes: a step-down module, which is connected to the charging interface and the control module respectively, and the step-down module is used to step down the charging voltage to output the supply voltage to the control module.

2. The circuit according to claim 1, characterized in that The sampling circuit is connected to a plurality of charging interfaces, the voltage reduction modules are multiple, the multiple voltage reduction modules are connected to the multiple charging interfaces in a one-to-one correspondence, and the multiple voltage reduction modules are connected to the control module.

3. The circuit according to claim 1, characterized in that The charging protection circuit also includes: A safety circuit is used to connect at least one of the sampling circuit, the control circuit and the voltage stabilizing circuit to the charging interface.

4. The circuit according to claim 1, characterized in that The charging protection circuit also includes: The isolation circuit is used to connect the sampling circuit and the control module.

5. A circuit board, characterized in that: The circuit board comprises the circuit according to any one of claims 1 to 4.

6. A device, characterized in that: The device comprises the circuit board as claimed in claim 5.

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