CN106471700A - Battery protection board, battery and mobile terminal - Google Patents

Abstract

An embodiment of the present invention provides a battery protection board, a battery and a mobile terminal, wherein the battery protection board includes: the protection circuit is connected with a charge-discharge loop of a battery in the mobile terminal and is used for controlling the on-off of the charge-discharge loop; the battery fuel gauge is characterized in that one end of the battery fuel gauge is connected to a first position of the charging and discharging loop, the other end of the battery fuel gauge is connected to a second position of the charging and discharging loop, the first position is located in the battery protection board, the second position is located in a main board of the mobile terminal, the first position and the second position are connected through a lead, in the process that the battery is charged and discharged through the charging and discharging loop, the battery fuel gauge detects the voltage drop generated by the impedance of the lead, and the electric quantity of the battery is determined according to the voltage drop. The embodiment of the invention can reduce the number of devices in the battery protection board, save the board distribution area and the cost of the battery protection board, reduce the failure rate of the battery protection board and reduce the heat productivity of the battery protection board.

Description

Battery protection board, battery and mobile terminal

technical field

The embodiments of the present invention relate to the field of mobile terminals, and more specifically, to a battery protection board, a battery and a mobile terminal.

Background technique

At present, mobile terminals (such as smart phones) are more and more favored by consumers, and the security of mobile terminals has become the focus of attention of users.

In order to ensure the safety of the battery inside the mobile terminal, it is necessary to install a battery protection board for the battery. Existing battery protection boards have various structures, and mobile terminals have special requirements on the integration and volume of the battery protection boards. Therefore, it is urgent to provide a battery protection board suitable for mobile terminals.

Contents of the invention

The present application provides a battery protection board and a battery suitable for a mobile terminal, and provides a mobile terminal.

In the first aspect, a battery protection board is provided, including: a protection circuit connected to the charging and discharging circuit of the battery in the mobile terminal, and the protection circuit is used to control the on and off of the charging and discharging circuit; the battery fuel gauge , one end of the battery fuel gauge is connected to the first position of the charge-discharge circuit, the other end of the battery fuel gauge is connected to the second position of the charge-discharge circuit, and the first position is located in the battery protection In the board, the second position is located in the main board of the mobile terminal, and the first position and the second position are connected by wires. During the process of charging and discharging the battery through the charging and discharging circuit , the battery fuel gauge detects the voltage drop caused by the impedance of the wire, and determines the battery capacity according to the voltage drop.

In a second aspect, a battery is provided, including an electric cell, and a battery protection plate as described in the first aspect, and the battery protection plate is connected to the electric cell.

A third aspect provides a mobile terminal, including a charging interface, the battery as described in the second aspect, and a mainboard, wherein the battery is connected to the charging interface.

In some implementation manners above, the battery protection board further includes: a temperature detection circuit for detecting the temperature of the battery; the battery fuel gauge is connected to the temperature detection circuit, and the battery fuel gauge is specifically used for : According to the temperature detected by the temperature detection circuit, and the corresponding relationship between temperature and the impedance (or resistance) of the wire, determine the impedance of the wire (that is, determine the resistance of the wire at the temperature detected by the temperature detection circuit Impedance); according to the impedance of the wire and the voltage drop generated by the impedance, the current flowing through the wire is determined; according to the current flowing through the wire, the electric quantity of the battery is determined.

In some implementations above, the battery fuel gauge includes the temperature detection circuit.

In some of the above implementations, the protection circuit includes: a field effect transistor, the field effect transistor is located in the charging and discharging circuit; a controller, the controller is connected to the field effect transistor (for example, connected to the field effect transistor The gate of the transistor), and the conduction and shutdown of the charging and discharging circuit are controlled through the field effect transistor.

In some implementation manners above, the battery fuel gauge is connected to the second position through a connector between the battery protection board and the main board.

In some of the above implementations, the protection circuit is the first protection circuit in the battery protection board, and the battery protection board further includes: a second protection circuit, the second protection circuit is connected to the charging and discharging circuit The charge and discharge circuit is protected against overvoltage and/or overcurrent through a fuse.

In some implementation manners above, the mobile terminal supports a normal charging mode and a fast charging mode, wherein the charging speed of the fast charging mode is greater than that of the normal charging mode.

In some implementation manners above, the charging current in the fast charging mode is greater than the charging current in the normal charging mode.

In some implementation manners above, the charging voltage in the fast charging mode is greater than the charging voltage in the normal charging mode.

In some implementation manners above, in the fast charging mode, the mobile terminal performs two-way communication with the adapter through the charging interface.

It should be understood that the battery fuel gauge may include two current detection points, one end of the battery fuel gauge may be the first current detection point of the battery fuel gauge, and the other end of the battery fuel gauge may be the second current detection point of the battery fuel gauge .

The battery protection board provided by the present application can not only reduce the number of devices in the battery protection board, save the layout area and cost of the battery protection board, reduce the failure rate of the battery protection board, but also reduce the heat generation of the battery protection board.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required in the embodiments of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Figure 1 is a schematic circuit diagram of a battery protection board.

Fig. 2 is a schematic circuit diagram of a battery protection board according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of the connection relationship between the battery protection board and the main board according to the embodiment of the present invention.

Fig. 4 is a schematic circuit diagram of a battery protection board according to an embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a battery according to an embodiment of the present invention.

Fig. 6 is a schematic structural diagram of a mobile terminal according to an embodiment of the present invention.

detailed description

Figure 1 is a schematic circuit diagram of a battery protection board. The battery protection board 10 of Fig. 1 includes:

The protection circuit 11 is connected to the charge and discharge circuit 13 of the battery in the mobile terminal, and the protection circuit 11 is used to control the conduction and shutdown of the charge and discharge circuit 13;

A current-sensing resistor 14 is connected in series in the charge-discharge circuit 13;

The battery fuel gauge 15 is connected to both ends of the current-sensing resistor 14. During the charging and discharging process of the battery through the charge-discharge circuit, the battery fuel gauge 15 detects the voltage drop generated by the impedance of the current-sensing resistor 14, and according to the The voltage drop determines the charge of the battery.

In some embodiments, the protection circuit 11 in FIG. 1 includes a control IC 16 and a pair of back-to-back MOS transistors T1 and T2. The control IC 16 is connected to the MOS transistor T1 and the MOS transistor T2 through the Cout terminal and the Dout terminal respectively.

In some embodiments, the Cout terminal may be an overcharge control terminal, and the switch of the MOS transistor is controlled by the gate voltage of the MOS transistor T2.

In some embodiments, the Dout terminal may be an over-discharge, over-current or short-circuit control terminal, and the switch of the MOS transistor is controlled by the gate voltage of the MOS transistor T1.

In some embodiments, P+ and P− represent the positive pole and the negative pole of the battery protection board 10 , respectively. Alternatively, P+ and P- respectively represent the positive pole and negative pole of the battery cell 12 connected through the battery protection board 10 .

The volume of mobile terminals is getting smaller and smaller, and the requirements for circuit integration are getting higher and higher. The battery protection board in this solution not only integrates the protection circuit, but also integrates the battery fuel gauge, which has a high degree of integration, and is very suitable for application in the mobile terminal to provide protection for the battery of the mobile terminal.

In the prior art, the battery protection board is generally sealed in the battery together with the battery cells. Due to the limited volume of the battery, the area of the battery protection board is relatively small, resulting in poor heat dissipation of the battery protection board.

Adopting the scheme in Fig. 1 can improve the integration level, but because the current-sensing resistor 14 generally has a small area and generates a large amount of heat, it may further aggravate the heating phenomenon of the battery protection board 10, so it can be considered to use the current-sensing resistor The area of the battery protection board 10 is increased to reduce the heat generation of the battery protection board 10 .

In order to achieve this purpose, the impedance of the wire in the charging and discharging circuit can be used to replace the current-sensing resistor. The area of the wire is larger than that of the special resistance element, which can better dissipate the heat generated by the resistance.

However, as mentioned above, the battery protection board is generally packaged in a small battery, and the area of the protection board itself is very small. , the resistance area may still be relatively small, and the heat generated by it still cannot be dissipated in time.

In order to increase the area of the wire replacing the current detection resistor in the current loop as much as possible, as shown in Figure 2, one current detection point of the battery fuel gauge can be connected to the current loop of the battery protection board, and the other of the battery fuel gauge can be connected to the current loop of the battery protection board. A current detection point is connected to the current loop of the main board through the connector between the battery protection board and the main board of the mobile terminal (it should be noted that the dotted line in FIG. 2 represents the current detection circuit of the battery fuel gauge). This can ensure that the area of this section of wire is large enough, and the heat generated can be dissipated in time, thereby reducing the heat generation of the battery protection board.

The impedance of the intercepted section of wire can be obtained by calculation or simulation. After obtaining the impedance of this section of wire, you can connect the battery protection board and the main board together, and then use an external power supply to add a constant current to the current loop to calibrate the impedance of this section of wire, which can ensure the battery power gauge. Sensing accuracy.

Furthermore, the impedance of this section of wire may change with the temperature of the battery or battery protection board. In the case of using this wire instead of the current-sensing resistor 14 , in order to more accurately measure the current flowing through this wire, in some embodiments, a temperature detection circuit may be added to the battery protection board 10 .

Specifically, referring to FIG. 3 , the battery protection board may further include: a temperature detection circuit 18 for detecting the temperature of the battery or the battery protection board; the battery fuel gauge 15 may be connected to the temperature detection circuit 18, and the battery fuel gauge 15 may specifically be used for: According to the temperature detected by the temperature detection circuit 18, and the corresponding relationship between the temperature and the impedance of this section of wire (this correspondence can be pre-stored and recorded in the memory of the battery protection board 10), determine the impedance of this section of wire at the current temperature; According to the impedance of this section of wire at the current temperature, the current flowing through this section of wire is detected; according to the current flowing through this section of wire, the battery capacity is determined.

In some embodiments, the temperature detection circuit may be integrated in the battery fuel gauge. In some embodiments, the temperature detection circuit may be provided separately from the battery fuel gauge.

In some embodiments, the temperature detection circuit can detect temperature through a thermistor. In some embodiments, the thermistor may be a negative temperature coefficient (Negative Temperature Coefficient, NTC) resistor or a positive temperature coefficient (Possitive Temperature Coefficient, PTC) resistor. In some embodiments, one end of the thermistor is connected to the positive terminal P+ of the battery protection board through a pull-up resistor.

The above protection circuit 11 may be the first protection circuit in the battery protection board 10. In order to further improve the protection performance of the battery protection board, optionally, in some embodiments, referring to FIG. 4, the battery protection board 10 may further include: The second protection circuit 21, the second protection circuit 21 can provide protection for the charging and discharging process of the battery when the protection circuit fails.

In some embodiments, the second protection circuit 21 can provide overvoltage or overcurrent protection for the charging and discharging process of the battery through a fuse. As shown in FIG. 4, the second protection circuit 21 may include a first fuse pin F1 and a second fuse pin F2. The fuse between the first fuse pin F1 and the second fuse pin F2 is blown.

By setting the two-level protection circuit, the safety of the charging and discharging process of the battery in the mobile terminal is further improved.

The battery protection board according to the embodiment of the present invention has been described in detail above with reference to FIGS. 1 to 4 . The battery and the mobile terminal according to the embodiment of the present invention will be described in detail below with reference to FIG. 5 and FIG. 6 .

Fig. 5 is a schematic structural diagram of a battery according to an embodiment of the present invention. The battery 500 of FIG. 5 includes:

battery cell 510; and

A battery protection board 520 , the battery protection board 520 is connected to the battery cell 510 .

It should be understood that the battery protection plate 520 in FIG. 5 may be the battery protection plate described above, and details are not described here to avoid repetition.

Fig. 6 is a schematic structural diagram of a mobile terminal according to an embodiment of the present invention. The mobile terminal 600 of Figure 6 includes:

Charging interface 610;

The battery 500 is connected to the charging interface 610 .

Optionally, as an embodiment, the mobile terminal 600 may support a normal charging mode and a fast charging mode, wherein the charging speed of the fast charging mode is greater than that of the normal charging mode.

Optionally, as an embodiment, the charging current in the fast charging mode is greater than that in the normal charging mode.

Optionally, as an embodiment, in the fast charging mode, the mobile terminal 600 performs two-way communication with the adapter through the charging interface 610 .

The embodiment of the present invention does not specifically limit the communication process between the mobile terminal and the adapter. For example, the communication between the mobile terminal and the adapter may refer to the handshake process between the two parties, that is, the mobile terminal and the adapter determine the charging mode, charging voltage, charging parameters such as current.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes. .

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (12)

1. a kind of battery protecting plate is it is characterised in that include：

Protection circuit, is connected with the charging and discharging circuit of the battery in mobile terminal, and described protection circuit is used for controlling described charge and discharge The conducting of The electric loop and shutoff；

Battery meter, one end of described battery meter is connected to the primary importance of described charging and discharging circuit, described battery electricity The other end of gauge is connected to the second position of described charging and discharging circuit, and described primary importance is located in described battery protecting plate, The described second position is located in the mainboard of described mobile terminal, passes through wire phase between described primary importance and the described second position Even, during described battery carries out discharge and recharge by described charging and discharging circuit, described battery meter detects described wire The pressure drop that produces of impedance, and determine the electricity of described battery according to described pressure drop.

2. battery protecting plate as claimed in claim 1 is it is characterised in that described battery protecting plate also includes：

Temperature sensing circuit, for detecting the temperature of described battery；

Described battery meter is connected with described temperature sensing circuit, described battery meter specifically for：

The temperature being detected according to described temperature sensing circuit, and temperature and the corresponding relation of the impedance of described wire, determine The impedance of described wire；

According to the impedance of described wire, and the pressure drop that described impedance produces, determine the electric current flowing through described wire；

According to the electric current flowing through described wire, determine the electricity of described battery.

3. battery protecting plate as claimed in claim 2 is it is characterised in that described battery meter includes described temperature detection electricity Road.

4. the battery protecting plate as any one of claim 1-3 is it is characterised in that described protection circuit includes：

Field effect transistor, described field effect transistor is located in described charging and discharging circuit；

Controller, described controller is connected with described field effect transistor, controls described charging and discharging circuit by described field effect transistor Conducting and shutoff.

5. the battery protecting plate as any one of claim 1-4 is it is characterised in that described battery meter is by described Adapter between battery protecting plate and described mainboard is connected to the described second position.

6. the battery protecting plate as any one of claim 1-5 is it is characterised in that described protection circuit is described battery The first protection circuit in protection board, described battery protecting plate also includes：

Second protection circuit, described second protection circuit is connected with described charging and discharging circuit, and by fuse to described discharge and recharge Loop carries out overvoltage and/or overcurrent protection.

7. a kind of battery is it is characterised in that include：

Battery core；

Battery protecting plate as any one of claim 1-6, described battery protecting plate is connected with described battery core.

8. a kind of mobile terminal is it is characterised in that include：

Charging inlet；

Battery as claimed in claim 7, described battery is connected with described charging inlet；

Described mainboard.

9. mobile terminal as claimed in claim 8 is it is characterised in that described mobile terminal supports normal charging mode and quick Charge mode, wherein, the charging rate of described fast charge mode is more than the charging rate of described normal charging mode.

10. mobile terminal as claimed in claim 9 is it is characterised in that the charging current of described fast charge mode is more than institute State the charging current of normal charging mode.

11. mobile terminals as claimed in claim 9 are it is characterised in that the charging voltage of described fast charge mode is more than institute State the charging voltage of normal charging mode.

12. mobile terminals as any one of claim 8-11 it is characterised in that under described fast charge mode, Described mobile terminal carries out two-way communication by described charging inlet and adapter.