Battery protection circuit and battery device including the same

Abstract

To provide a battery protection circuit and a battery device including the same.SOLUTION: A battery protection circuit includes: a detection circuit unit that outputs a wake-up signal when voltage is input to an external terminal; a voltage distribution unit connected in parallel to the external terminal; a control unit that inputs distributed voltage from the voltage distribution unit and outputs an overvoltage determination signal when receiving the wake-up signal from the detection circuit unit; a logic unit that includes an AND gate and an inverter, in which the inverter receives an input of the voltage distributed from the voltage distribution unit and transmits an inverter output signal to the AND gate, and the AND gate receives an input of the overvoltage determination signal and the inverter output signal and outputs the switching control signal; and a switching unit that controls the connection between a battery module and the external terminal according to the switching control signal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery protection circuit and a battery device including the same. [Background technology]

[0002] Generally, a rechargeable secondary battery is combined with a circuit to form a battery pack, and charging and discharging are performed through the external terminals of the battery pack. When an external power source is connected through the external terminals of the battery pack, the battery cells are charged by the external power source supplied through the external terminals and a charging / discharging circuit. When the external terminals are connected to a load, power from the battery cells is supplied to the load through the charging / discharging circuit and the external terminals.

[0003] Recently, a method for managing a battery pack more efficiently by dividing the state of the battery pack into a sleep mode and a wake-up mode has been used. For example, when the battery pack is in use, the battery pack is put into the wake-up mode to operate normally, and when the battery pack or the device to which the battery pack is attached is not used for a predetermined period of time, the battery pack is put into the sleep mode to reduce energy consumption of the battery pack.

[0004] However, if the processor of the battery management system is arbitrarily woken up due to other surrounding noise, energy consumption increases further, further increasing the risk of the battery being discharged. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2020-518096 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems, and aims to provide a battery device including a protection circuit for preventing the battery pack from waking up when a low voltage or noise is applied to the battery pack. [Means for solving the problem]

[0007] To achieve the above object, a battery protection circuit according to one embodiment of the present invention includes a detection circuit unit that outputs a wake-up signal when a voltage is input to an external terminal, a control unit that outputs a switching control signal when the wake-up signal is received from the detection circuit unit, and a switching unit that controls connection between a battery module and the external terminal according to the switching control signal.

[0008] If the control unit does not receive the wake-up signal from the detection circuit unit, the control unit does not output the switching control signal so that the switching unit is opened.

[0009] The detection circuit unit may include a first resistor, a second resistor, and a second diode connected in series between the external terminal and ground, a first diode connected between a node between the first resistor and the second resistor and the external terminal, and a transistor connected between the external terminal and the controller and controlled by the voltage of the node.

[0010] The transistor is connected to the node between the first resistor and the second resistor. threshold Voltage exceed In this case, a wake-up signal can be transmitted to the control unit.

[0011] The transistor is connected to the node between the first resistor and the second resistor. threshold Voltage not exceed In this case, the wake-up signal is not transmitted to the control unit.

[0012] A method for protecting a battery module according to one embodiment of the present invention includes a step in which a detection circuit unit outputs a wake-up signal when a voltage is input from an external terminal, a step in which a control unit outputs a switching control signal when the control unit receives the wake-up signal from the detection circuit unit, and a step in which a switching unit controls a connection between the battery module and the external terminal according to the switching control signal.

[0013] The method may further include the step of, when the control unit does not receive the wake-up signal from the detection circuit unit, not outputting the switching control signal so that the switching unit is opened.

[0014] The detection circuit unit may include a first resistor, a second resistor, and a second diode connected in series between the external terminal and ground, a first diode connected between a node between the first resistor and the second resistor and the external terminal, and a transistor connected between the external terminal and the controller and controlled by the voltage of the node.

[0015] The detection circuit outputs a wake-up signal when a voltage is input from an external terminal, and the transistor detects that the voltage at the node between the first resistor and the second resistor is equal to the voltage at the node between the first resistor and the second resistor. threshold Voltage exceed If so, outputting a wake-up signal.

[0016] The step of not outputting the switching control signal to open the switching unit when the control unit does not receive the wake-up signal from the detection circuit unit is performed by detecting whether the voltage at the node between the first resistor and the second resistor is equal to the voltage at the node between the first resistor and the second resistor of the transistor. threshold Voltage not exceed In this case, the wake-up signal may not be output.

[0017] A battery device according to one embodiment of the present invention includes a battery module, an external terminal for connecting an external device to the battery module, and a protection circuit. The protection circuit includes a detection circuit unit that outputs a wake-up signal when a voltage is input to the external terminal, a control unit that outputs a switching control signal when the wake-up signal is received from the detection circuit unit, and a switching unit that controls connection between the battery module and the external terminal according to the switching control signal. [Effects of the Invention]

[0018] A battery device according to an embodiment of the present invention can reduce energy consumption for a battery module.

[0019] A battery device according to an embodiment of the present invention can ensure stability by preventing the battery device from waking up and current from flowing when a low voltage due to noise or the like is input. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a block diagram showing a battery charging / discharging system according to an embodiment of the present invention; [Figure 2] 1 is a diagram showing a battery device according to an embodiment of the present invention; [Figure 3] 2 is a circuit diagram illustrating an overvoltage charge protection unit and a low voltage detection circuit unit of a battery device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. Identical or similar components will be denoted by the same or similar reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "section" used in the following description are used interchangeably for ease of description and do not have any distinct meanings or functions. Furthermore, in describing the embodiments disclosed herein, if a detailed description of related publicly known technology is deemed to obscure the gist of the embodiments disclosed herein, such a detailed description will be omitted. Furthermore, the accompanying drawings are merely provided to facilitate understanding of the embodiments disclosed herein, and the accompanying drawings should not be construed as limiting the technical concepts disclosed herein, but should be understood to include all modifications, equivalents, or alternatives within the concept and technical scope of the present invention.

[0022] In this specification, the terms "comprise" or "have" and the like are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof stated in the specification, and should be understood as not precluding the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0024] FIG. 1 is a block diagram that schematically illustrates a battery charge / discharge system 1 according to an embodiment of the present invention.

[0025] Referring to FIG. 1, a battery charge / discharge system 1 includes a battery device 10 and an external device 20.

[0026] The battery device 10 has a structure that allows it to be electrically connected to an external device 20. When the external device 20 is a charger, the battery device 10 is charged by receiving external power via the charger 20. When the external device 20 is a load, the battery device 10 operates as a power source that supplies power to the load 20 and is discharged.

[0027] FIG. 2 is a diagram showing a battery device 10 according to one embodiment of the present invention.

[0028] The battery device 10 includes a battery module 100, an external terminal 200, and a protection circuit 300.

[0029] The battery module 100 includes a plurality of battery cells (not shown). In one embodiment, the battery cells may be rechargeable secondary batteries. A predetermined number of battery cells may be connected in series to form a battery module.

[0030] The external terminal 200 is a terminal for connecting the external device 20 to the battery device 10.

[0031] The protection circuit 300 is a circuit for controlling the connection between the battery module 100 and the external terminal 200. When an overvoltage charger is connected to the external terminal 200, the protection circuit 300 prevents the battery module 100 from being charged, thereby preventing an overcharge current from flowing. In addition, when a low-voltage load is connected to the external terminal 200, the protection circuit 300 can also prevent current from being output from the battery module 100.

[0032] The protection circuit 300 includes a control unit 310, an overvoltage charge protection unit 330, and a low voltage detection circuit unit 331. 50 and a switching unit 370.

[0033] The control unit 310 may acquire basic data for checking the state of the battery device 10 and control the operation of the battery. The control unit 310 may control the connection between the battery module 100 and the external terminal 200 to control charging and discharging of the battery module 100. For example, the control unit 310 may output a signal to control the switching unit 370.

[0034] When an overvoltage charger is connected to the external terminal 200, the overvoltage charging protection unit 330 can disconnect the connection between the battery module 100 and the external terminal 200 by turning off the switching unit 370 to ensure the safety of the battery module 100.

[0035] The overvoltage charging protection unit 330 includes a voltage distribution unit 331 and a logic unit 333 .

[0036] The voltage distribution unit 331 has one end connected to the positive terminal (+) of the external terminal 200 and the other end connected to the negative terminal (-) of the external terminal 200. The voltage distribution unit 331 distributes the voltage input to the external terminal 200 at a predetermined ratio and transmits the distributed voltage to the control unit 310 and the logic unit 333.

[0037] The control unit 310 can compare the voltage transmitted from the voltage dividing unit 331 with an internally set overvoltage level voltage value and output an overvoltage determination signal S1 to the logic unit 333. If the divided voltage is equal to or greater than the overvoltage level voltage value, the overvoltage determination signal S1 may be a disable signal. If the divided voltage is less than the overvoltage level voltage value, the overvoltage determination signal S1 may be an enable signal. For ease of explanation, the following description will be given assuming that the enable signal is a high-level signal ("1") and the disable signal is a low-level signal ("0").

[0038] The control unit 310 also stores information about a dedicated charger depending on the type of battery module 100. For example, information about a method for applying a voltage by a dedicated charger of the battery module is stored. When a voltage is input from the voltage distribution unit 331 according to a certain time sequence, the control unit 310 determines whether the time sequence of the input voltage is the same as the time sequence of the dedicated charger of the battery module 100, and recognizes that the external device 20 connected to the external terminal 200 is a dedicated charger. In this case, the control unit 310 can directly transmit a switching control signal to the switching unit 370 to turn on the switching unit 370.

[0039] The logic unit 333 receives the overvoltage determination signal and the voltage distributed from the voltage distribution unit 331 and can output a switching control signal S3.

[0040] When a low voltage due to noise or the like is input to the external terminal 200, the low voltage detection circuit unit 350 prevents the control unit 310 from waking up in order to reduce energy consumption in the battery module, thereby preventing connection between the battery module 100 and the external terminal 200.

[0041] The low voltage detection circuit unit 350 includes a detection circuit unit 351. The detection circuit unit 351 includes a transistor Q1 that operates based on a voltage value of a preset low voltage level.

[0042] The switching unit 370 is connected in series between the battery module 100 and the external terminal 200 to control an electrical connection between the battery module 100 and the external terminal 200. For example, the switching unit 370 is connected between a positive output terminal from which a positive voltage of the battery module 100 is output and a positive connection terminal C(+) connected to the external device 20. The switching unit 370 is controlled by at least one of a signal transmitted from the control unit 310 and a switching control signal S3 output from the logic unit 333.

[0043] FIG. 3 is a circuit diagram illustrating an overvoltage charge protection unit 330 and a low voltage detection circuit unit 350 of a battery device according to an embodiment of the present invention.

[0044] The voltage dividing unit 331 includes at least two Zener diodes ZD3 and ZD4 and a resistor R3. The at least two Zener diodes ZD3 and ZD4 and the resistor R3 are connected in series between the external terminal 200 and ground. The voltage dividing unit 331 can determine the voltage dividing ratio by adjusting the values ​​of the at least two Zener diodes ZD3 and ZD4 and the resistor R3. The voltage dividing unit 331 can transmit the voltage at a node N1 between the resistor R3 and the Zener diode ZD4, i.e., the voltage divided at a certain ratio, to the logic unit 333.

[0045] The logic section 333 includes an inverter and an AND gate.

[0046] The inverter outputs an inverter output signal S2 in response to the voltage distributed from the voltage distribution unit 331. When the voltage input to the inverter is equal to or greater than a predetermined overvoltage level, the inverter can output a disable signal. When the voltage input to the inverter is less than the predetermined overvoltage level, the inverter can output an enable signal. For ease of explanation, the following description will be given assuming that the disable signal of the inverter output signal S2 is a low-level signal ("0") and the enable signal is a high-level signal ("1"). Here, the enable signal of the overvoltage determination signal S1 of the control unit 310 and the enable signal of the inverter output signal S2 may be signals of the same level, for example, a high-level signal, or the disable signal of the overvoltage determination signal S1 and the disable signal of the inverter output signal S2 may be signals of the same level, for example, a low-level signal.

[0047] The AND gate is a logic element that performs logical AND. The AND gate performs logical AND between the overvoltage determination signal S1 and the inverter output signal S2 from the control unit 310, and outputs a switching control signal S3. The output S3 of the AND gate is as shown in Table 1.

[0048] [Table 1]

[0049] The switching unit 370 is opened or closed according to a switching control signal S3 output from the logic unit 333. For example, if the switching control signal S3 is a high-level signal (“1”), the switching unit 370 is closed, connecting the battery module 100 and the external terminal 200. On the other hand, if the switching control signal S3 is a low-level signal (“0”), the switching unit 370 is opened, disconnecting the battery module 100 and the external terminal 200.

[0050] The detection circuit unit 351 includes at least two Zener diodes ZD1 and ZD2, resistors R1 and R2, and a transistor Q1. Here, the resistors R1 and R2 and the Zener diode ZD2 are connected in series between the external terminal 200 and ground. The Zener diode ZD1 is connected between the external terminal 200 and a node N2 between the resistors R1 and R2. The transistor Q1 is connected between the external terminal 200 and the control unit 310 and can be controlled by the voltage of the node N2.

[0051] Hereinafter, the operation of the overvoltage charging protection unit 330 will be described in detail with reference to FIG.

[0052] In the overvoltage charging protection unit 330, the voltage Vz(ZD4) at node N1 is input to the input terminal (input 1) of the control unit 310 and the inverter. If Vz(ZD4) is equal to or greater than a preset overvoltage level, the control unit 310 can output a low-level overvoltage determination signal S1 through the output terminal (output 1). If Vz(ZD4) is equal to or greater than a preset overvoltage level, the inverter can also output a low-level inverter output signal S2. In this case, the logic unit 333 can output a low-level switching control signal S3.

[0053] When the voltage Vz(ZD4) at node N1 is less than the voltage value of the preset overvoltage level, the control unit 310 may output a high-level overvoltage determination signal S1 through the output terminal (output 1). When Vz(ZD4) is less than the voltage value of the preset overvoltage level, the inverter may also output a high-level inverter output signal S2. In this case, the logic unit 333 may output a high-level switching control signal S3.

[0054] If the voltage input to external terminal 200 is A(V), and A(V) ≥ Vz(ZD3) + Vz(ZD4), Vz(ZD4) is equal to or greater than the preset overvoltage level. Therefore, both overvoltage determination signal S1 and inverter output signal S2 of control unit 310 are low-level signals. Therefore, logic unit 333 outputs a low-level switching control signal S3, preventing switching unit 370 from shorting. Even if control unit 310 malfunctions, inverter output signal S2 remains low, preventing switching unit 370 from shorting. Therefore, logic unit 333 outputs a low-level switching control signal S3 regardless of overvoltage determination signal S1. Therefore, switching unit 370 does not short-circuit.

[0055] On the other hand, when the voltage input to the external terminal 200 is A (V) and A (V) < Vz(ZD3) + Vz(ZD4), Vz(ZD4) is less than the voltage value of the overvoltage level. As a result, both the overvoltage determination signal S1 and the inverter output signal S2 of the control unit 310 are high-level signals. Therefore, since the logic unit 333 outputs a high-level switching control signal S3, the switching unit 370 is short-circuited, and the battery module 100 and the external terminal 200 are connected.

[0056] When a dedicated charger for the battery module 100 is connected to the external terminal 200, the dedicated charger inputs a voltage in a preset time sequence. When a voltage is input to the input terminal (input 1) in the preset time sequence, the control unit 310 recognizes the external device 20 connected to the external terminal 200 as the dedicated charger 20 and can directly transmit a switching control signal for turning on the switching unit 370 to the switching unit 370. For example, when the periods of maintaining a voltage value equal to or higher than the overvoltage level and the periods of maintaining a voltage value lower than the overvoltage level are alternately input three or more times, the control unit 310 determines that a dedicated charger for the battery module 100 is connected. Therefore, the control unit 310 can directly transmit a switching control signal for turning on the switching unit 370 to the switching unit 370.

[0057] Here, although it was described that the reference voltages used as the thresholds for the inverter and the control unit 310 to detect the overvoltage state have the same reference at the voltage value of the overvoltage level, the reference voltages may have different values from each other. <L

[0058] Hereinafter, the operation of the low voltage detection circuit unit 350 will be described in detail with reference to FIG. 3.

[0059] Noise, for example, a low voltage, is input to the external terminal 200 of the battery device 10 by a human hand. At this time, the input voltage is B (V), and the thresholdLet the voltage be Vth(Q1). Then, the voltage at node N2, that is, the voltage applied to the gate of transistor Q1, is - {B(V)-Vz(ZD2)}× R1 ÷(R2+R1).

[0060] Transistor Q1 threshold When the voltage Vth(Q1) is higher than the voltage of the node N2, i.e., when the voltage input to the external terminal 200 is higher than the voltage value of the set low voltage level, the transistor Q1 is turned on, causing a current to flow from the external terminal 200 to the input terminal (input 2) of the controller 310, thereby transmitting a wake-up signal to the controller 310. As a result, the controller 310 can output a switching control signal in response to the voltage B(V) input to the external terminal 200.

[0061] In contrast, the transistor Q1 threshold If the voltage Vth(Q1) is smaller than the voltage applied to the gate, i.e., if the voltage input to the external terminal 200 is lower than the voltage value of the set low voltage level, the transistor Q1 is not turned on, the wake-up signal is not transmitted to the input terminal (input 2) of the control unit 310, and the control unit 310 does not operate.

[0062] The overvoltage charging protection unit 330 and the low voltage detection circuit unit 350 according to the above-described embodiments can be mounted on a single printed circuit board (PCB) and coupled to the battery module, or can be mounted on separate printed circuit boards and coupled to the battery module.

[0063] According to the battery device of the present invention, the battery device can be protected from an overcharge current flowing when an overvoltage charger is connected to the battery device.

[0064] According to the battery device of the present invention, even when the battery management system is not operating, the battery device can be protected from an overcharge current.

[0065] According to the battery device of the present invention, a dedicated charger can be recognized without a separate terminal, and there is no need to manufacture an additional circuit, thereby reducing costs.

[0066] Unless explicitly stated in order or unless otherwise stated, steps constituting a method according to the present invention may be performed in any suitable order. The present invention is not necessarily limited to the order in which the steps are described. The use of all examples or exemplary terms (e.g., etc.) in the present invention is merely for the purpose of describing the present invention in detail and is not intended to limit the scope of the present invention. Furthermore, those skilled in the art will recognize that various modifications, combinations, and variations can be made within the scope of the appended claims or their equivalents.

[0067] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to these, and various modifications and improvements made by those skilled in the art to which the present invention pertains also fall within the scope of the present invention. [Explanation of symbols]

[0068] 10 Battery device 20 External device 100 Battery Module 200 External terminal 310 Control Unit 331 Voltage distribution unit 333 Logic Section 351 Detection circuit section 370 Switching Unit

Claims

1. a detection circuit unit that outputs a wake-up signal when a voltage is input to an external terminal; a voltage distribution unit connected in parallel to the external terminal; a control unit that receives a wake-up signal from the detection circuit unit, inputs a distributed voltage from the voltage distribution unit, and outputs an overvoltage determination signal; a logic unit including an AND gate and an inverter, the inverter receiving the divided voltage from the voltage dividing unit and transmitting an inverter output signal to the AND gate, the AND gate receiving the overvoltage determination signal and the inverter output signal and outputting a switching control signal; a switching unit that controls a connection between the battery module and an external terminal according to the switching control signal.

2. The battery protection circuit according to claim 1 , wherein the control unit does not output the switching control signal so that the switching unit is opened when the wake-up signal is not received from the detection circuit unit.

3. 2. The battery protection circuit of claim 1, wherein the detection circuit unit includes: a first resistor, a second resistor, and a second diode connected in series between the external terminal and ground; a first diode connected between the external terminal and a connection point between the first resistor and the second resistor; and a transistor connected between the external terminal and the controller and controlled by a voltage at the connection point.

4. 4. The battery protection circuit according to claim 3, wherein the transistor transmits a wake-up signal to the control unit when a voltage at the connection point between the first resistor and the second resistor exceeds a threshold voltage of the transistor.

5. 4. The battery protection circuit according to claim 3, wherein the transistor does not transmit a wake-up signal to the control unit when the voltage at the connection point between the first resistor and the second resistor does not exceed a threshold voltage of the transistor.

6. a detection circuit unit outputting a wake-up signal when a voltage is input from an external terminal; a voltage dividing unit inputting a voltage of the external terminal; a control unit receiving a wake-up signal from the detection circuit unit, inputting a distributed voltage from the voltage distribution unit, and outputting an overvoltage determination signal; a logic unit including an AND gate and an inverter outputting a switching control signal based on the divided voltage and the overvoltage determination signal; a switching unit controlling a connection between the battery module and an external terminal according to the switching control signal; The step of outputting the switching control signal comprises: the inverter transmitting an inverter output signal to the AND gate in response to the divided voltage; and the AND gate outputs the switching control signal according to the inputs of the overvoltage determination signal and the inverter output signal.

7. The method of claim 6, further comprising: when the control unit does not receive a wake-up signal from the detection circuit unit, not outputting a switching control signal to open the switching unit.

8. 8. The method of claim 7, wherein the detection circuit unit includes: a first resistor, a second resistor, and a second diode connected in series between the external terminal and ground; a first diode connected between the external terminal and a connection point between the first resistor and the second resistor; and a transistor connected between the external terminal and a controller and controlled by a voltage at the connection point.

9. The step of outputting a wake-up signal when a voltage is input from an external terminal by the detection circuit unit includes:

9. The method of claim 8, further comprising the step of: outputting a wake-up signal from the transistor when a voltage at the connection point between the first resistor and the second resistor exceeds a threshold voltage of the transistor.

10. The step of not outputting the switching control signal so that the switching unit is opened when the control unit does not receive a wake-up signal from the detection circuit unit comprises:

9. The method for protecting a battery module according to claim 8, wherein the transistor does not output a wake-up signal if the voltage at the connection point between the first resistor and the second resistor does not exceed a threshold voltage of the transistor.

11. a battery module; an external terminal for connecting an external device to the battery module; a protection circuit, the protection circuit comprising: a detection circuit unit that outputs a wake-up signal when a voltage is input to an external terminal; a voltage distribution unit connected in parallel to the external terminal; a control unit that receives a wake-up signal from the detection circuit unit, inputs a distributed voltage from the voltage distribution unit, and outputs an overvoltage determination signal; a logic unit including an AND gate and an inverter, the inverter receiving the divided voltage from the voltage dividing unit and transmitting an inverter output signal to the AND gate, the AND gate receiving the overvoltage determination signal and the inverter output signal and outputting a switching control signal; a switching unit that controls connection between the battery module and an external terminal according to the switching control signal.

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