A control circuit for a battery protection board

Abstract

The application relates to a control circuit of a battery protection plate, which comprises a battery cell connecting terminal, a battery cell anti-reverse connection circuit and a battery connecting terminal, the battery cell anti-reverse connection circuit is connected between the battery cell connecting terminal and the battery connecting terminal, the battery cell connecting terminal is used for connecting a battery cell, and the battery connecting terminal is used for connecting an external electronic device; the battery cell anti-reverse connection circuit comprises a conduction state and a disconnection state; when the battery cell is connected to the battery cell connecting terminal in a forward direction, the battery cell anti-reverse connection circuit is in the conduction state; and when the battery cell is connected to the battery cell connecting terminal in a reverse direction, the battery cell anti-reverse connection circuit is in the disconnection state. The control circuit of the battery protection plate provided by the application can automatically enter the disconnection state when the battery cell is reversely connected, so as to cut off the current path between the battery cell and the external electronic device, and avoid damaging the external electronic device when the battery cell is reversely connected.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a control circuit for a battery protection board. Background Technology

[0002] In portable consumer electronics, due to size and space constraints and cost control requirements, battery systems are typically designed as two separate components: a protection board and a battery cell. When the positive and negative terminals of the battery cell are designed with smooth flat surfaces, users may accidentally insert the cell in the wrong direction during insertion, causing a short circuit between the positive and negative terminals. This could damage the battery itself, severely damage the protection board and downstream circuitry attached to the device, or even lead to a safety accident.

[0003] To solve the problem of reversed battery cell installation, the relevant technology involves protective measures on the single-cell assembly sleeve and the single cell itself. For example, a buzzer is installed inside the battery cell assembly. When the battery cell is installed in reverse, the buzzer will sound to indicate that the battery cell assembly is abnormal. When the positive and negative terminals of the battery cell are correctly placed into the battery cell assembly, the battery cell will not trigger the buzzer to sound.

[0004] However, the buzzer's audible alert may not be easily heard in noisy environments. As a result, users may ignore the buzzer's warning, leading to damage to the device or safety hazards if the battery is forcibly inserted. Utility Model Content

[0005] This application provides a control circuit for a battery protection board to solve the technical problem that the sound prompts using a buzzer are not easily heard in noisy environments, which may lead to the battery cells being installed incorrectly and damaging the equipment or causing safety hazards.

[0006] In a first aspect, this application provides a control circuit for a battery protection board. The control circuit includes a cell connection terminal, a cell reverse connection protection circuit, and a battery connection terminal. The cell reverse connection protection circuit is connected between the cell connection terminal and the battery connection terminal. The cell connection terminal is used to connect a cell, and the battery connection terminal is used to connect an external electronic device. The cell reverse connection protection circuit includes a conducting state and a disconnecting state.

[0007] When the battery cell is connected to the battery cell connection terminal in the forward direction, the battery cell reverse connection protection circuit is in the conducting state;

[0008] When the battery cell is connected in reverse to the battery cell connection terminal, the battery cell reverse connection protection circuit is in the disconnected state.

[0009] In some possible implementations, the cell connection terminal includes a positive cell connection terminal and a negative cell connection terminal, the battery connection terminal includes a positive battery connection terminal and a negative battery connection terminal, and the cell reverse connection protection circuit includes a first P-type MOSFET and a second P-type MOSFET;

[0010] In this configuration, the gate of the first P-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the battery, the source of the first P-type MOS transistor is connected to the positive terminal of the battery cell, the drain of the first P-type MOS transistor is connected to the drain of the second P-type MOS transistor, the gate of the second P-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the battery, and the source of the second P-type MOS transistor is connected to the positive terminal of the battery.

[0011] In some possible implementations, the reverse connection protection circuit being in the conducting state when the battery cell is positively connected to the battery cell connection terminal includes:

[0012] When the positive terminal of the battery cell is connected to the positive terminal of the battery cell and the negative terminal of the battery cell is connected to the negative terminal of the battery cell, both the first P-type MOSFET and the second P-type MOSFET are turned on, and the reverse connection protection circuit of the battery cell is in the on state.

[0013] In some possible implementations, the condition that the reverse connection protection circuit is in the disconnected state when the battery cell is reverse-connected to the battery cell connection terminal includes:

[0014] When the negative terminal of the battery cell is connected to the positive terminal of the battery cell, and the positive terminal of the battery cell is connected to the negative terminal of the battery cell, neither the first P-type MOSFET nor the second P-type MOSFET is turned on, and the reverse connection protection circuit of the battery cell is in the disconnected state.

[0015] In some possible implementations, the reverse connection protection circuit for the battery cell further includes a first current-limiting resistor and a second current-limiting resistor, wherein the first current-limiting resistor is connected between the gate of the first P-type MOS transistor and the negative terminal of the battery cell, and the second current-limiting resistor is connected between the gate of the second P-type MOS transistor and the negative terminal of the battery cell.

[0016] In some possible implementations, the control circuit further includes a cell charge / discharge protection circuit, which is connected between the cell reverse connection protection circuit and the battery connection terminal. The cell charge / discharge protection circuit can be selectively in an open or closed loop.

[0017] When the current of the control circuit exceeds a preset value, the cell charge / discharge protection circuit is in the disconnected loop.

[0018] When the current of the control circuit does not exceed the preset value, the cell charging and discharging protection circuit is in the closed loop.

[0019] In some possible implementations, the cell charge / discharge protection circuit includes a power management chip and an N-type composite MOSFET. The power management chip has a positive power supply pin, a negative power supply pin, a carry pulse output pin, and a digital signal output pin. The positive power supply pin is connected to the source of the second P-type MOSFET and the positive terminal of the battery. The negative power supply pin is connected to the negative terminal of the cell and the negative terminal of the battery. The carry pulse output pin and the digital signal output pin are connected to the gate of the N-type composite MOSFET. The source of the N-type composite MOSFET is connected to the negative terminal of the cell and the negative terminal of the battery.

[0020] In some possible implementations, the N-type composite MOS transistor includes a first N-type MOS transistor and a second N-type MOS transistor;

[0021] The gate of the first N-type MOS transistor is connected to the carry pulse output pin, the source of the first N-type MOS transistor is connected to the negative terminal of the battery, the drain of the first N-type MOS transistor is connected to the drain of the second N-type MOS transistor, the gate of the second N-type MOS transistor is connected to the digital signal output pin, and the source of the second N-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the power supply.

[0022] In some possible implementations, the battery cell charge / discharge protection circuit further includes a first capacitor, a second capacitor, and a third capacitor. The power management chip further includes a voltage measurement pin. The first capacitor is connected to the positive power supply pin and the negative power supply pin. The third capacitor is connected to the voltage measurement pin. The second capacitor is connected between the first capacitor and the third capacitor.

[0023] In some possible implementations, the cell charge / discharge protection circuit further includes a third current-limiting resistor connected between the third capacitor and the voltage measurement pin.

[0024] The technical solutions provided in this application have the following advantages compared with the prior art:

[0025] The control circuit of the battery protection board provided in this application embodiment includes a cell connection terminal, a cell reverse connection protection circuit, and a battery connection terminal. The cell reverse connection protection circuit is connected between the cell connection terminal and the battery connection terminal. The cell connection terminal is used to connect a cell, and the battery connection terminal is used to connect an external electronic device. The cell reverse connection protection circuit includes a conducting state and a disconnected state. When the cell is connected to the cell connection terminal in the forward direction, the cell reverse connection protection circuit is in the conducting state. When the cell is connected to the cell connection terminal in the reverse direction, the cell reverse connection protection circuit is in the disconnected state.

[0026] Thus, by setting a reverse connection protection circuit between the cell connection terminal and the battery connection terminal, this application can automatically enter a conducting state when the cell is connected in the correct direction and automatically enter a disconnected state when the cell is connected in the reverse direction, thereby cutting off the current path between the cell and external electronic equipment and preventing damage to external electronic equipment when the cell is installed in reverse. This can prevent damage caused by reverse insertion of the cell without user intervention, thereby improving the technical problem that the sound prompts of the buzzer used in related technologies are not easily heard in noisy environments, which may still cause damage to equipment or safety hazards due to reverse insertion of the cell. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0030] Figure 1 A circuit diagram of a control circuit for a battery protection board provided in an embodiment of this application;

[0031] Figure 2 A circuit diagram of the reverse connection protection circuit for battery cells provided in an embodiment of this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] The circuit includes: a reverse connection protection circuit for the battery cell (100), a charge / discharge protection circuit for the battery cell (200), a positive terminal V+ for the battery cell, a negative terminal V- for the battery cell, a first P-type MOSFET D1, a second P-type MOSFET D2, an N-type composite MOSFET D3, a first N-type MOSFET G1, a second N-type MOSFET G2, a first current-limiting resistor R1, a second current-limiting resistor R2, a third current-limiting resistor R3, a first capacitor C3, a second capacitor C4, a third capacitor C5, a power management chip U1, a positive power supply pin VDD, a negative power supply pin VSS, a carry pulse output pin CO, a digital signal output pin DO, a voltage measurement pin VM, a positive battery terminal VBAT, a negative battery terminal GND, a gate VGS, a source S, and a drain D. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0036] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0037] In portable consumer electronics, due to size and space constraints and cost control requirements, battery systems are typically designed as two separate components: a protection board and a battery cell. When the positive and negative terminals of the battery cell are designed with smooth flat surfaces, users may accidentally insert the cell in the wrong direction during insertion, causing a short circuit between the positive and negative terminals. This could damage the battery itself, severely damage the protection board and downstream circuitry attached to the device, or even lead to a safety accident.

[0038] To solve the problem of reversed battery cell installation, the relevant technology involves protective measures on the single-cell assembly sleeve and the single cell itself. For example, a buzzer is installed inside the battery cell assembly. When the battery cell is installed in reverse, the buzzer will sound to indicate that the battery cell assembly is abnormal. When the positive and negative terminals of the battery cell are correctly placed into the battery cell assembly, the battery cell will not trigger the buzzer to sound.

[0039] However, the buzzer's audible alert may not be easily heard in noisy environments. As a result, users may ignore the buzzer's warning, leading to damage to the device or safety hazards if the battery is forcibly inserted.

[0040] To address the technical problem in existing technologies where the sound prompts using buzzers are easily inaudible in noisy environments, potentially leading to damage to equipment or safety hazards due to reversed battery cell installation, this application provides a control circuit for a battery protection board that automatically enters a disconnect state when a battery cell is connected in reverse, thereby cutting off the current path between the battery cell and external electronic devices. This prevents damage to external electronic devices when the battery cell is installed in reverse and avoids damage caused by reversed battery cell insertion without user intervention.

[0041] See Figure 1 - Figure 2This application provides a control circuit for a battery protection board. The control circuit includes a cell connection terminal, a cell reverse connection protection circuit 100, and a battery connection terminal. The cell reverse connection protection circuit 100 is connected between the cell connection terminal and the battery connection terminal. The cell connection terminal is used to connect a cell, and the battery connection terminal is used to connect an external electronic device. The cell reverse connection protection circuit 100 includes a conducting state and a disconnecting state.

[0042] When the battery cell is connected to the battery cell connection terminal in the forward direction, the battery cell reverse connection protection circuit 100 is in the conducting state;

[0043] When the battery cell is connected in reverse to the battery cell connection terminal, the battery cell reverse connection protection circuit 100 is in the disconnected state.

[0044] This embodiment provides a reverse connection protection circuit 100 between the cell connection terminal and the battery connection terminal. This circuit automatically enters a conducting state when the cell is connected in the correct direction and automatically enters a disconnected state when the cell is connected in the reverse direction. This cuts off the current path between the cell and the external electronic device, preventing damage to the external electronic device when the cell is installed in the wrong direction. It prevents damage caused by reverse insertion of the cell without user intervention. This also improves the technical problem that the sound prompts of the buzzer used in related technologies are not easily heard in noisy environments, which may still cause damage to the equipment or safety hazards due to reverse insertion of the cell.

[0045] In some possible implementations, the cell connection terminals include a positive cell connection terminal V+ and a negative cell connection terminal V-, the battery connection terminals include a positive battery connection terminal VBAT and a negative battery connection terminal GND, and the cell reverse connection protection circuit 100 includes a first P-type MOSFET D1 and a second P-type MOSFET D2.

[0046] In this configuration, the gate VGS of the first P-type MOSFET D1 is connected to the negative terminal V- of the battery cell and the negative terminal GND of the battery; the source S of the first P-type MOSFET D1 is connected to the positive terminal V+ of the battery cell; the drain D of the first P-type MOSFET D1 is connected to the drain D of the second P-type MOSFET D2; the gate VGS of the second P-type MOSFET D2 is connected to the negative terminal V- of the battery cell and the negative terminal GND of the battery; and the source S of the second P-type MOSFET D2 is connected to the positive terminal VBAT of the battery.

[0047] Among them, the first P-type MOSFET D1 and the second P-type MOSFET D2 can meet the circuit parameter requirements for high current.

[0048] The battery positive terminal VBAT and the battery negative terminal GND form the input and output current interfaces for the battery's positive and negative terminals. The battery cells can be charged through these two interfaces, and the battery cells' power can also be output to the load through these two interfaces.

[0049] In addition, the input and output voltages of the battery positive terminal VBAT and the battery negative terminal GND are processed by the reverse connection protection circuit 100 and the overcurrent protection circuit (i.e., the battery charge and discharge protection circuit 200). Therefore, the input and output voltages of the battery positive terminal VBAT and the battery negative terminal GND can be directly used to connect to external electronic devices.

[0050] In some possible implementations, the reverse connection protection circuit 100 is in the conducting state when the battery cell is positively connected to the battery cell connection terminal, including:

[0051] When the positive terminal of the battery cell is connected to the positive terminal V+ and the negative terminal of the battery cell is connected to the negative terminal V-, both the first P-type MOSFET D1 and the second P-type MOSFET D2 are turned on, and the reverse connection protection circuit 100 is in the on state.

[0052] In some possible implementations, the battery cell reverse connection protection circuit 100 being in the disconnected state when the battery cell is reverse connected to the battery cell connection terminal includes:

[0053] When the negative terminal of the battery cell is connected to the positive terminal V+ and the positive terminal of the battery cell is connected to the negative terminal V-, neither the first P-type MOSFET D1 nor the second P-type MOSFET D2 is turned on, and the reverse connection protection circuit 100 is in the disconnected state.

[0054] When the battery cell is connected in the forward direction, the positive terminal V++ of the battery cell is connected to the positive terminal of the battery cell, and the negative terminal V- of the battery cell is connected to the negative terminal of the battery cell. At this time, the gate VGS of the first P-type MOSFET D1 and the second P-type MOSFET D2 are at a low level, which meets the conduction condition. Therefore, both the first P-type MOSFET D1 and the second P-type MOSFET D2 are turned on. The positive terminal V++ of the battery cell can output current and voltage through the first P-type MOSFET D1 and the second P-type MOSFET D2, forming a load power supply and a closed loop for charging the battery cell with the negative terminal V- of the battery cell.

[0055] In case of abnormal operation, i.e., when the battery cell is connected in reverse, the positive terminal V++ of the battery cell is connected to the negative terminal of the battery cell, and the negative terminal V- of the battery cell is connected to the positive terminal of the battery cell. At this time, the gate VGS of the first P-type MOSFET D1 and the second P-type MOSFET D2 are at a high level, which does not meet the conduction condition. Therefore, the gate VGS of the first P-type MOSFET D1 and the second P-type MOSFET D2 are in the off state. The current and voltage of the positive terminal V++ and the negative terminal V- of the battery cell cannot be conducted through the first P-type MOSFET D1 and the second P-type MOSFET D2. That is, the reverse connection protection circuit 100 disconnects the input and output circuits of the battery cell.

[0056] In some possible implementations, the reverse connection protection circuit 100 for the battery cell further includes a first current-limiting resistor R1 and a second current-limiting resistor R2. The first current-limiting resistor R1 is connected between the gate VGS of the first P-type MOSFET D1 and the negative terminal V- of the battery cell, and the second current-limiting resistor R2 is connected between the gate VGS of the second P-type MOSFET D2 and the negative terminal V- of the battery cell.

[0057] In some possible implementations, the control circuit further includes a cell charge and discharge protection circuit 200, which is connected between the cell reverse connection protection circuit 100 and the battery connection terminal. The cell charge and discharge protection circuit 200 can be selectively in an open circuit or a closed circuit.

[0058] When the current of the control circuit exceeds a preset value, the cell charge and discharge protection circuit 200 is in the disconnected loop.

[0059] When the current of the control circuit does not exceed the preset value, the cell charging and discharging protection circuit 200 is in the closed loop.

[0060] The current in the control circuit can be either the charging current or the discharging current.

[0061] In some possible implementations, the cell charge / discharge protection circuit 200 includes a power management chip U1 and an N-type composite MOSFET. The power management chip U1 has a positive power supply pin VDD, a negative power supply pin VSS, a carry pulse output pin CO, and a digital signal output pin DO. The positive power supply pin VDD is connected to the source S of the second P-type MOSFET D2 and the battery positive terminal VBAT. The negative power supply pin VSS is connected to the cell negative terminal V- and the battery negative terminal GND. The carry pulse output pin CO and the digital signal output pin DO are connected to the gate VGS of the N-type composite MOSFET. The source S of the N-type composite MOSFET is connected to the cell negative terminal V- and the battery negative terminal GND.

[0062] In some possible implementations, the N-type composite MOS transistor includes a first N-type MOS transistor G1 and a second N-type MOS transistor G2;

[0063] The gate VGS of the first N-type MOSFET G1 is connected to the carry pulse output pin CO, the source S of the first N-type MOSFET G1 is connected to the battery negative terminal GND, the drain D of the first N-type MOSFET G1 is connected to the drain D of the second N-type MOSFET G2, the gate VGS of the second N-type MOSFET G2 is connected to the digital signal output pin DO, and the source S of the second N-type MOSFET G2 is connected to the cell negative terminal V- and the power supply negative pin VSS.

[0064] In some possible implementations, the battery cell charge and discharge protection circuit 200 further includes a first capacitor C3, a second capacitor C4, and a third capacitor C5. The power management chip U1 further includes a voltage measurement pin VM. The first capacitor C3 is connected to the positive power supply pin VDD and the negative power supply pin VSS. The third capacitor C5 is connected to the voltage measurement pin VM. The second capacitor C4 is connected between the first capacitor C3 and the third capacitor C5.

[0065] In some possible implementations, the cell charge / discharge protection circuit 200 further includes a third current-limiting resistor R3, which is connected between the third capacitor C5 and the voltage measurement pin VM.

[0066] The first capacitor, C3, is a momentary filter capacitor for power management chip U1. The second capacitor, C4, and the third capacitor, C5, are capacitors for filtering out momentary interference on the negative terminal. The third current-limiting resistor, R3, is an overcurrent detection and current-limiting resistor for power management chip U1.

[0067] The working principle of the battery cell charging and discharging protection circuit 200 is as follows: When the charging current exceeds the preset value of the power management chip U1, the power management chip U1 pulls down the fourth pin of the N-type composite MOS transistor D3 through the third pin, so that the gate VGS of the first P-type MOS transistor D1 in the N-type composite MOS transistor D3 is pulled down. The first P-type MOS transistor D1 does not meet the conduction condition, and the battery cell charging circuit is disconnected.

[0068] When the discharge current exceeds the preset value of the power management chip U1, the power management chip U1 pulls down the 5th pin of the N-type composite MOSFET D3 through the 1st pin, causing the gate VGS of the second P-type MOSFET D2 inside the N-type composite MOSFET D3 to be pulled down. The second P-type MOSFET D2 does not meet the conduction condition, thus disconnecting the cell discharge circuit.

[0069] The current detection method of the control circuit can be to determine whether the circuit current exceeds the preset value by measuring the internal resistance difference between pin 2 (voltage measurement pin VM) and pin 6 (power supply negative pin VSS) of the power management chip U1.

[0070] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0071] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0073] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0074] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0076] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0077] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control circuit for a battery protection board, characterized in that, The control circuit includes a cell connection terminal, a cell reverse connection protection circuit, and a battery connection terminal. The cell reverse connection protection circuit is connected between the cell connection terminal and the battery connection terminal. The cell connection terminal is used to connect the cell, and the battery connection terminal is used to connect to an external electronic device. The cell reverse connection protection circuit includes an on state and an off state. When the battery cell is connected to the battery cell connection terminal in the forward direction, the battery cell reverse connection protection circuit is in the conducting state; When the battery cell is connected in reverse to the battery cell connection terminal, the battery cell reverse connection protection circuit is in the disconnected state.

2. The control circuit according to claim 1, characterized in that, The cell connection terminal includes a positive cell connection terminal and a negative cell connection terminal; the battery connection terminal includes a positive battery connection terminal and a negative battery connection terminal; the cell reverse connection protection circuit includes a first P-type MOSFET and a second P-type MOSFET. In this configuration, the gate of the first P-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the battery, the source of the first P-type MOS transistor is connected to the positive terminal of the battery cell, the drain of the first P-type MOS transistor is connected to the drain of the second P-type MOS transistor, the gate of the second P-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the battery, and the source of the second P-type MOS transistor is connected to the positive terminal of the battery.

3. The control circuit according to claim 1, characterized in that, When the battery cell is connected to the battery cell connection terminal in the forward direction, the battery cell reverse connection protection circuit is in the conducting state, including: When the positive terminal of the battery cell is connected to the positive terminal of the battery cell and the negative terminal of the battery cell is connected to the negative terminal of the battery cell, both the first P-type MOSFET and the second P-type MOSFET are turned on, and the reverse connection protection circuit of the battery cell is in the on state.

4. The control circuit according to claim 1, characterized in that, When the battery cell is connected in reverse to the battery cell connection terminal, the battery cell reverse connection protection circuit is in the disconnected state, including: When the negative terminal of the battery cell is connected to the positive terminal of the battery cell, and the positive terminal of the battery cell is connected to the negative terminal of the battery cell, neither the first P-type MOSFET nor the second P-type MOSFET is turned on, and the reverse connection protection circuit of the battery cell is in the disconnected state.

5. The control circuit according to claim 2, characterized in that, The reverse connection protection circuit for the battery cell further includes a first current-limiting resistor and a second current-limiting resistor. The first current-limiting resistor is connected between the gate of the first P-type MOS transistor and the negative terminal of the battery cell, and the second current-limiting resistor is connected between the gate of the second P-type MOS transistor and the negative terminal of the battery cell.

6. The control circuit according to claim 1, characterized in that, The control circuit also includes a cell charging and discharging protection circuit, which is connected between the cell reverse connection protection circuit and the battery connection terminal. The cell charging and discharging protection circuit can be selectively in an open circuit or a closed circuit. When the current of the control circuit exceeds a preset value, the cell charge / discharge protection circuit is in the disconnected loop. When the current of the control circuit does not exceed the preset value, the cell charging and discharging protection circuit is in the closed loop.

7. The control circuit according to claim 5, characterized in that, The battery cell charge / discharge protection circuit includes a power management chip and an N-type composite MOSFET. The power management chip has a positive power supply pin, a negative power supply pin, a carry pulse output pin, and a digital signal output pin. The positive power supply pin is connected to the source of the second P-type MOSFET and the positive terminal of the battery. The negative power supply pin is connected to the negative terminal of the battery cell and the negative terminal of the battery. The carry pulse output pin and the digital signal output pin are connected to the gate of the N-type composite MOSFET. The source of the N-type composite MOSFET is connected to the negative terminal of the battery cell and the negative terminal of the battery.

8. The control circuit according to claim 7, characterized in that, The N-type composite MOS transistor includes a first N-type MOS transistor and a second N-type MOS transistor; The gate of the first N-type MOS transistor is connected to the carry pulse output pin, the source of the first N-type MOS transistor is connected to the negative terminal of the battery, the drain of the first N-type MOS transistor is connected to the drain of the second N-type MOS transistor, the gate of the second N-type MOS transistor is connected to the digital signal output pin, and the source of the second N-type MOS transistor is connected to the negative terminal of the battery cell and the negative terminal of the power supply.

9. The control circuit according to claim 7, characterized in that, The battery cell charge and discharge protection circuit further includes a first capacitor, a second capacitor, and a third capacitor. The power management chip further includes a voltage measurement pin. The first capacitor is connected to the positive power supply pin and the negative power supply pin. The third capacitor is connected to the voltage measurement pin. The second capacitor is connected between the first capacitor and the third capacitor.

10. The control circuit according to claim 9, characterized in that, The cell charge / discharge protection circuit also includes a third current-limiting resistor, which is connected between the third capacitor and the voltage measurement pin.

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