WO2015005600A1 - Battery protection circuit using single mosfet and protection ic system therefor - Google Patents

Abstract

The present invention relates to a battery charge/discharge protection apparatus that forms a battery pack by being connected to a positive terminal and a negative terminal. The protection apparatus includes a single MOSFET and a protection IC controlling the single MOSFET. A source terminal of the single MOSFET is directly connected to the negative terminal of the battery. A drain terminal of the single MOSFET is the negative terminal of the battery pack. REPRESENTATIVE DRAWING: FIG. 2:

Description

Battery Protection Circuit Using Single MOSFET and Protection IC System

The present invention relates to battery protection and ICs for controlling transistors that block or conduct current flowing through the battery.

1 is a diagram illustrating a battery protection circuit 100 according to an exemplary embodiment.

Referring to FIG. 1, the battery protection circuit 100 according to an exemplary embodiment includes a first internal connection terminal B + 11 and a second internal connection terminal B− 12. In addition, the battery protection circuit 100 includes a first external connection terminal (P +) 13 and a second external connection terminal (P-) 14. The first external connection terminal (P +) 13 and the second external connection terminal (P-) 14 are connected to the charger during charging and the electronic device (eg, portable terminal, etc.) operated by battery power during discharge. Is connected to.

The battery protection circuit 100 includes two FETs 111 and 112, a protection IC 110, resistors R ₁ and R ₂ , a capacitor C ₁ , and a diode. At this time, the drain terminals of each of the first FET 111 and the second FET 112 are electrically connected to each other.

The protection IC 110 is connected to the first internal connection terminal B + 11, which is a positive terminal of the battery, through the resistor R ₁ , and senses whether the charging voltage or the discharge voltage is applied and the battery voltage. Terminal (V _DD ), the reference terminal (V _SS ) which is the reference for the operating voltage inside the protection IC 110, the detection terminal (V-) for detecting the charge / discharge and overcurrent conditions, and the The discharge interruption signal output terminal D _OUT for turning off one FET 111 and the charge interruption signal output terminal C _OUT for turning off the second FET 112 in an overcharge state. At this time, the inside of the protection IC 110 includes a reference voltage setting unit, a comparison unit for comparing the reference voltage and the charge / discharge voltage, an overcurrent detector, and a charge / discharge detector. Here, the criterion for determining the state of charge and discharge can be changed to the specification required by the user, and the charge / discharge state is determined by recognizing the voltage difference of each terminal of the protection IC 110 according to the determined criterion. do.

When the protection IC 110 reaches the over-discharge state, the discharge cutoff signal output terminal goes low to turn off the first FET 111. When the overcharge state reaches the overcharge state, the charge cutoff signal output terminal goes low to the second FET ( 112 is turned off. In addition, when overcurrent flows, the second FET 112 is turned off during charging and the first FET 111 is turned off during discharge.

On the other hand, the resistor (R1) and the capacitor (C ₁ ) serves to stabilize the fluctuation of the power supply of the protection IC (110). The resistor R ₁ is connected between the first internal connection terminal B + 11 and the V _DD terminal of the protection IC 110, and the capacitor C ₁ is connected to the V _DD terminal and the second terminal of the protection IC 110. It is connected between the internal connection terminal (B-) (12). At this time, to increase the value of the resistor (R ₁₎ of the resistor (R ₁₎ due to high the detection voltage by the current to be penetrated into the interior of the voltage detecting when protection IC (110) is to be set to an appropriate value equal to or less than 1KΩ . In addition, for stable operation, the value of the capacitor C ₁ should be set to an appropriate value of 0.01 μs or more. For example, in the battery protection circuit 100 according to one embodiment, the value of the resistor (R ₁₎ is the value of 1KΩ and the capacitor (C ₁₎ can be 0.1㎌.

The resistor R ₁ and the resistor R ₂ become current limiting resistors when the high voltage charger or the charger exceeding the absolute maximum rating of the protection IC 110 is connected upside down. In this case, the resistor R _{2 is} connected between the sensing terminal V− of the protection IC 110 and the node n1 to which the source terminal Source 2 of the second FET 112 is connected. In this case, since the resistor R ₁ and the resistor R ₂ may cause power consumption, the sum of the resistance values of the resistor R ₁ and the resistor R ₂ is generally set to be larger than 1 KΩ. If the resistor R ₂ is too large, no recovery may occur after the overcharge cutoff, and thus the value of the resistor R ₂ is set to a value of 10 KΩ or less. For example, in the battery protection circuit 100 according to an exemplary embodiment, the battery protection circuit 100 may be 2.2 KΩ.

The battery protection circuit 100 according to the above-described embodiment includes two MOSFETs for controlling charge and discharge due to the characteristics of the battery protection IC performing protection operations during charging and discharging. In this case, the dual-MOSFET has twice as much internal resistance as the single MOSFET. In this case, a relatively high internal resistance may cause a rise and fall of the battery during battery charging and discharging, thereby lowering the use time of the battery.

Therefore, the present invention is to provide a technique for solving the above problems.

In order to solve the above problems, the present invention provides a battery protection IC using a single MOSFET.

Battery charge and discharge protection device according to an aspect of the present invention is connected to the positive terminal and the negative terminal of the battery constitutes a battery pack. This protection device includes one MOSFET; And a protection IC controlling the one MOSFET. The source terminal of the one MOSFET is connected directly to the negative terminal of the battery, the drain terminal of the MOSFET is characterized in that the negative terminal of the battery pack.

In this case, the first terminal of the protection IC is connected to the gate terminal to control the voltage of the gate terminal of the one MOSFET, the drain terminal or the source terminal when the one MOSFET is controlled to be off A pair of diodes may be connected in series in opposite directions between the source terminal and the drain terminal so that current flowing into the bypass of the single MOSFET is performed.

In this case, the bypassed current may be configured to flow through the protection IC.

According to another aspect of the present invention, a battery pack includes a battery; And a battery charge / discharge protection device connected to the positive terminal and the negative terminal of the battery. In this case, the battery charge and discharge protection device includes a protection IC for controlling one MOSFET and the one MOSFET, the source terminal of the one MOSFET is directly connected to the negative terminal of the battery, the drain of the one MOSFET The terminal is characterized in that the negative terminal of the battery pack.

In this case, the first terminal of the protection IC is connected to the gate terminal to control the voltage of the gate terminal of the one MOSFET, the drain terminal or the source terminal when the one MOSFET is controlled to be off A pair of diodes may be connected in series in opposite directions between the source terminal and the drain terminal such that current flowing into the MOSFET bypasses the MOSFET.

In this case, the bypassed current may be configured to flow through the protection IC.

According to another aspect of the present invention, a battery charge / discharge control IC for controlling one MOSFET connected to the negative terminal of the battery and the drain terminal of the battery pack including the battery may be provided. have. The battery charge / discharge control IC may include: a first terminal for controlling a gate voltage of the one MOSFET so that no current flows through the one MOSFET when the battery is blocked from being charged or discharged; And at least one pair of bypass terminals to bypass the first current flowing through the battery through the battery charge / discharge control IC when the battery is blocked from being charged or discharged.

According to still another aspect of the present invention, a battery charge / discharge control IC for controlling a transistor that blocks or conducts current flowing through a battery may be provided. The battery charge / discharge control IC includes an internal transistor; And a control logic for generating a control signal for controlling the transistor and the inner-transistor. In this case, the control logic controls the transistor so that no current flows through the transistor when the charging or discharging of the battery is interrupted, and the first current flowing through the battery is bypassed through the inner-transistor. It may be arranged to control an inner-transistor.

In this case, when the charging or discharging of the battery is blocked and then allowed, the control logic controls the inner-transistor so that no current flows through the inner-transistor, and the second current flowing through the battery is the transistor. And control the transistor to flow through.

In this case, the first current and the second current may be opposite to each other.

In this case, the internal transistor and the transistor may be a MOSFET.

In this case, a first diode for bypassing the charging direction current and a second diode for bypassing the discharge direction current may be connected between the source terminal and the drain terminal of the transistor.

In this case, a Zener diode may be connected between the gate terminal and the source terminal of the transistor.

In this case, a diode for bypassing the charging direction current or the discharge direction current may be connected between the source terminal and the drain terminal of the internal transistor.

In this case, a Zener diode may be connected between the gate terminal and the source terminal of the inner-transistor.

According to another aspect of the invention, a transistor for blocking or conducting current flowing through a battery; And an IC comprising an internal-transistor and a control logic for generating a control signal for controlling the transistor and the internal-transistor. In this case, the control logic controls the transistor so that no current flows through the transistor when the charging or discharging of the battery is interrupted, and the first current flowing through the battery is bypassed through the internal transistor. And to control the inner-transistor.

In this case, when the charging or discharging of the battery is blocked and then allowed, the control logic controls the inner-transistor so that no current flows through the inner-transistor, and the second current flowing through the battery is the transistor. And control the transistor to flow through.

In this case, the first current and the second current may be opposite to each other.

In this case, further comprising a resistor and a capacitor for stabilizing the fluctuation of the power supply of the battery protection IC, and a Zener diode for protecting against static electricity that may flow between the gate and the source of each of the transistor and the inner-transistor. It may be configured to include more.

According to the present invention, by using a single MOSFET, the internal resistance can be reduced by half than that of the dual MOSFET. As a result, the voltage rise and fall may be reduced when the battery is charged and discharged, and the battery usage time may increase.

1 is a diagram for describing a battery protection circuit according to an exemplary embodiment.

2 is a view for explaining a battery protection circuit according to an embodiment of the present invention.

3 illustrates a protection IC and an external transistor according to an embodiment of the present invention.

4 is a view for explaining a change in the control circuit output according to the state of charge in the battery protection circuit according to an embodiment of the present invention.

5A and 5B are diagrams for describing a flow of current according to a charging state in a battery protection circuit according to an exemplary embodiment of the present invention.

6 is a view for explaining a change in the control circuit output according to the discharge state in the battery protection circuit according to an embodiment of the present invention.

7A and 7B are diagrams for describing a flow of current according to a discharge state in a battery protection circuit according to an embodiment of the present invention.

8 is a view for explaining a battery pack according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described. However, the present invention is not limited to the embodiments described herein and may be implemented in various other forms. The terminology used herein is for the purpose of understanding the embodiments and is not intended to limit the scope of the invention. Also, the singular forms used below include the plural forms unless the phrases clearly indicate the opposite meanings.

<Example 1>

Hereinafter, the battery protection circuit 200 according to an embodiment of the present invention will be described with reference to FIGS. 2 and 3.

2 is a diagram illustrating a battery protection circuit 200 according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating a protection IC 210 and an external transistor 220 according to an embodiment of the present invention. It is for the drawing.

As shown in FIG. 2, the battery protection circuit 200 according to an exemplary embodiment of the present invention may include a first internal connection terminal B + 21, a second internal connection terminal B− 22, and a first connection terminal. An external connection terminal P + 23 and a second external connection terminal P- 24 are provided. At this time, the first external connection terminal (P +) 23 and the second external connection terminal (P-) 24 is a terminal that can be in direct contact with a separate external device. This may be implemented in the same manner as the battery protection circuit 100 shown in FIG. 1.

In addition, the battery protection circuit 200 according to an embodiment of the present invention includes one external-transistor 220, a protection IC 210, resistors R ₁ , R ₂ , and a capacitor C ₁ . Can be configured. The protection IC 210 may include a first inner-transistor 221, a second inner-transistor 222, and a control logic 230. At this time, the source terminal of the external transistor 220 is connected to the second internal connection terminal (B-) 22, and the drain terminal is connected to the second external connection terminal (P-) 24. It is connected. In this case, the resistor R ₂ is connected between the sensing terminal V− of the protection IC 210 and the third node n3, and the resistor R ₁ and the capacitor C ₁ are described above. It is connected in the same structure as the battery protection circuit 100 according to. In this case, the third node n3 may be a drain terminal of the external-transistor 220 and the second external connection terminal P- 24. Here, the outer-transistor 220, the first inner-transistor 221, and the second inner-transistor 222 may each be a MOSFET.

In addition, in one embodiment of the present invention, a control diode is connected between the gate and the source terminal of each of the outer-transistor 220, the first inner-transistor 221, and the second inner-transistor 222. In addition, it may serve to protect the circuit from electrostatic discharge (ESD) that may be introduced from the outside.

 1 and 2, the structure of the battery protection circuit 200 is compared with each other. The battery protection circuit 100 according to an embodiment includes two FETs 111 and 112. The battery protection circuit 200 according to an embodiment includes a single external transistor 220. According to such a configuration, the internal resistance of the battery protection circuit 200 is reduced to 1/2, so that the voltage rise and fall in the battery charging and discharging may be reduced, and the use time of the battery may be increased.

On the other hand, as shown in Figure 3, the protection IC 210 according to an embodiment of the present invention is the terminal (V _DD ), the reference terminal (V _SS ), the sensing terminal (V-), and the overcharge state and / or A charge / discharge control signal output terminal (C _OUT & D _OUT ) 25 for turning off the external-transistor 220 in the over-discharge state. In addition, the protection IC 210 may include a first inner-transistor 221, a second inner-transistor 222, and a control circuit 230. In this case, the gate terminals of each of the first inner-transistor 221 and the second inner-transistor 222 are connected to the control circuit 230. At this time, the control circuit 230 is configured to control the outer-transistor 220, the first inner-transistor 221, and the second inner-transistor 222.

At this time, a diode is connected between the source terminal and the drain terminal of the external-transistor 220 and between the charge / discharge control signal output terminal 25 and the source terminal of the external-transistor 220. In addition, a diode is connected between the source terminal and the drain terminal of the first inner-transistor 221, and between one side of the control circuit 230 and the source terminal of the first inner-transistor 221. In this case, the second inner-transistor 222 may be configured in the same manner as the first inner-transistor 221.

On the other hand, in the battery protection circuit 200 according to an embodiment of the present invention, the change in the output of the control circuit 230 and the flow of the current according to the charging and discharging state will be described with reference to FIGS. .

4 is a view for explaining a change in the control circuit output according to the state of charge in the battery protection circuit 200 according to an embodiment of the present invention, Figures 5a and 5b is a battery protection according to an embodiment of the present invention 6 is a view for explaining the flow of the current according to the charging state in the circuit 200, Figure 6 is a view for explaining a change in the control circuit output according to the discharge state in the battery protection circuit 200 according to an embodiment of the present invention 7A and 7B are views for explaining the flow of current according to a discharge state in the battery protection circuit 200 according to an embodiment of the present invention.

As shown in FIG. 4, the charging process of the battery protection circuit 200 according to an embodiment of the present disclosure may be divided into, for example, normal charging sections P1 and P3 and charging blocking sections P2. At this time, in the case of the normal charging section (P1, P3) as shown in Figure 5a, the current flows in the first direction (51), in the case of the charging cutoff section (P2) as shown in Figure 5b A current path through which current can flow in the second direction 52 may be provided. Hereinafter, each section according to the state of charge of the battery protection circuit 200 will be described in detail.

Normal charging section P1 : When the battery is normally charged, the battery protection circuit 200 outputs a high level charge / discharge control signal through the charge / discharge control signal output terminal 25 to external- The transistor 220 is configured to be controlled in an ON state. Accordingly, as shown in FIG. 5A, the charging current flows in the first direction 51 through the outer transistor 220. At the same time, the first inner-transistor 221 and the second inner-transistor 222 are controlled in an OFF-state to control the first inner-transistor 221 and the second inner-transistor 222. It is configured so that no current flows through the terminals 31 and 33 and the second terminals 32 and 34. In this case, for example, the first direction 51 may be counterclockwise. That is, the direction may be a direction from the second internal connection terminal (B-) 22 to the second external connection terminal (P-) 24 through the source terminal and the drain terminal of the external transistor 220.

Charge interruption section (P2) : When the charge current is to be cut off due to the overcharge of the battery and the inflow of excessive charge current while maintaining the normal charge state, the charge / discharge control signal output terminal (25) at the overcharge occurrence detection time point (T1). The low-level charge / discharge control signal is outputted to control the external-transistor 220 to the off-state so that no current flows through the external-transistor 220. At the same time, by controlling the first inner-transistor 221 on-state and controlling the second inner-transistor 222 to be off-state, as shown in FIG. 5B, the first inner-transistor 221 And a current path through which the current can flow in the second direction 52 through the first terminal 31 and the second terminal 32. Accordingly, the charge interruption section P2 is continued until it is possible to return to the normal charging state again. In this case, the second direction 52 may be opposite to the first direction 51. That is, the direction from the second external connection terminal P- to the second internal connection terminal B- via the first terminal 31 and the second terminal 32 of the first inner-transistor 221 may be a number. have.

In order to return from the charging cutoff state P2 to the normal charging state P3, a certain amount of discharge current must flow, and according to the control state in the above-described charging cutoff period P2, the current path of the discharge current is provided. .

Normal charging section (P3) : When the charging return determination point (T2) for normal charging again after the charging interruption section (P2) is determined, the charge and discharge control signal output terminal 25 at the charging return determination point (T2). The high-level charge / discharge control signal is output to control the external transistor 220 to be in an on-state, such that a charging current flows in the first direction 51 through the external transistor 220. At the same time, the first inner-transistor 221 and the second inner-transistor 222 are controlled off-state, so that the first terminals 31 of each of the first inner-transistor 221 and the second inner-transistor 222 are controlled. And 33 so that no current flows through the second terminals 32 and 34.

On the other hand, as shown in Figure 6, the discharge process of the battery protection circuit 200 according to an embodiment of the present invention, for example, may be divided into a normal discharge period (P4, P6) and discharge interruption interval (P5). . In this case, in the normal discharge sections P4 and P6, current flows in the third direction 61 as shown in FIG. 7A, and in the charge blocking section P2, as shown in FIG. 7B. A current path through which current can flow in the fourth direction 62 may be provided. Hereinafter, each section of the discharging process of the battery protection circuit 200 will be described in detail.

Normal discharge section P4 : When the battery is normally discharged, the battery protection circuit 200 outputs a high level charge / discharge control signal through the charge / discharge control signal output terminal 25 to external-transistor 220. ) Is controlled on-state. Accordingly, as shown in FIG. 7A, the discharge current flows in the third direction 61 through the outer transistor 220. At the same time, the first inner-transistor 221 and the second inner-transistor 222 are controlled off-state, so that the first terminals 31 of each of the first inner-transistor 221 and the second inner-transistor 222 are controlled. And 33 so that no current flows through the second terminals 32 and 34. In this case, for example, the third direction 61 may be clockwise. That is, the direction may be a direction from the second external connection terminal (P-) 24 to the second internal connection terminal (B-) 22 through the drain terminal and the source terminal of the external transistor 220.

Discharge interruption section (P5) : When the discharge current is to be interrupted due to over discharge of the battery and inflow of excessive discharge current while maintaining a normal discharge state, the charge / discharge control signal output terminal at the over discharge occurrence detection time point (T3). A low level charge / discharge control signal is output through 25 to control the external-transistor 220 to the off-state so that no current flows through the external-transistor 220. At the same time, by controlling the second inner-transistor 222 on-state and controlling the first inner-transistor 221 off-state, as shown in FIG. 7B, the second inner-transistor 222 is controlled. It is configured to provide a current path through which the current can flow in the fourth direction 62 through the first terminal 33 and the second terminal 34. Accordingly, the discharge interruption section P5 is continued until the return to the normal discharge state is possible again. In this case, for example, the fourth direction 62 may be opposite to the third direction 61. That is, the second external connection terminal (P-) 24 from the second internal connection terminal (B-) 22 through the first terminal 33 and the second terminal 34 of the second internal-transistor 222. It may be a direction leading to).

In order to return from the discharge cutoff state P5 to the normal discharge state P6, a certain amount of charge current must flow, and according to the control state in the discharge cutoff period P5 described above, the current path of the charge current is provided. .

Normal discharge section (P6) : When the discharge return determination time point T4 for normal discharge is determined after the discharge interruption section (P5), the charge / discharge control at high level is performed through the charge / discharge control signal output terminal (25). By outputting a signal to control the external-transistor 220 in the on-state, the discharge current flows in the third direction 61 through the external-transistor 220. At the same time, the first inner-transistor 221 and the second inner-transistor 222 are controlled off-state, so that the first terminals 31 of each of the first inner-transistor 221 and the second inner-transistor 222 are controlled. And 33 so that no current flows through the second terminals 32 and 34.

<Example 2>

Meanwhile, a battery protection IC according to another embodiment of the present invention will be described.

Battery protection IC 210 (i.e., protection IC) according to another embodiment of the present invention is adapted to control transistor 220 (i.e., external-transistor) that blocks or conducts current flowing through the battery. In this case, the battery protection IC 210 may include internal- transistors 221 and 222; And a control logic 230 for generating a control signal for controlling the transistor 220 and the inner- transistors 221 and 222.

In this case, the control logic 230 controls the transistor 220 so that a current does not flow through the transistor 220 when the charging or discharging of the battery is blocked, and a first current that may flow through the battery is internal. -To control the inner- transistors 221, 222 to be bypassed through the transistors 221, 222. In addition, the control logic 230 controls the inner- transistors 221 and 222 so that current does not flow through the inner- transistors 221 and 222 when the charging or discharging of the battery is blocked and then allowed again. The transistor 220 is controlled to allow the second current flowing through the transistor 220 to flow through the transistor 220. In this case, the first current and the second current may be opposite to each other.

Inner- transistors 221, 222 and transistor 220 may be MOSFETs.

The first diode 510 for bypassing the charging direction current and the second diode 520 for bypassing the discharge direction current may be connected between the source terminal and the drain terminal of the transistor 220. In addition, a zener diode 530 may be connected between the gate terminal and the source terminal of the transistor 220.

In addition, a diode 540 for bypassing the charging direction current or the discharge direction current may be connected between the source terminal and the drain terminal of the internal transistors 221 and 222. The zener diode 550 may be connected between the gate terminal and the source terminal of the internal transistors 221 and 222.

<Example 3>

On the other hand, a battery overcurrent blocking device according to another embodiment of the present invention will be described.

Battery overcurrent blocking device according to another embodiment of the present invention, a transistor for blocking or conducting current flowing through the battery; And an IC including an intra-transistor and a control logic. In this case, the control logic is configured to generate a control signal for controlling the transistor and the internal transistor, and may be configured in the same way as the control logic of the battery protection IC according to the second embodiment.

In addition, the battery over-current blocking device further includes a resistor and a capacitor for stabilizing the fluctuation of the power supply of the battery protection IC, and against the static electricity that can flow between the gate and the source stage of each of the transistor and the internal-transistor. It further comprises a diode for protection.

In this case, in the second and third embodiments, the battery protection IC may correspond to the protection IC 210 described in the first embodiment, and the control logic may correspond to the control circuit 230 described above. In addition, the transistor may correspond to the outer-transistor 220, and the inner-transistor may correspond to the first inner-transistor 221 and the second inner-transistor 222.

<Example 4>

On the other hand, a battery pack including a battery protection IC according to an embodiment of the present invention described above will be described with reference to FIG.

8 is a view for explaining a battery pack 300 according to another embodiment of the present invention.

As shown in FIG. 8, according to another embodiment of the present invention, a battery pack 300 includes a protection circuit module protecting a battery cell 70 as a protection module package 90 in a package form. It has a structure interposed in the 70 and the upper case 80. The battery pack 300 includes a battery cell 70, a protection module package 90, and an upper case 80. The battery cell 70 has a negative electrode tab 73 and a positive electrode plate 74 formed on an upper surface 71. The protection module package 90 is connected to the negative electrode tab 73 and the positive electrode plate 74 of the battery cell 70 to package a protection circuit element that protects the battery cell 70. The upper case 80 is coupled to an upper portion of the battery cell 70 to cover the protection module package 90, and the openings 81 and 83 exposing the terminal pad 85 of the protection module package 90 to the top. Is formed. The openings 81 and 83 include a first opening 81 of which the negative terminal pad is exposed and a second opening 83 of which the positive electrode terminal pad is exposed.

In addition, the battery pack 300 may include an upper insulating sheet 75 installed above the battery cell 70, a lower insulating sheet 91 installed below the battery cell 70, a lower case 93, and a battery cell ( And a packaging label 95 surrounding the outer side of 70.

For example, the battery pack 300 may be implemented in the form of a thin square plate. That is, the battery cell 70 has a thin rectangular plate shape, and the upper insulating sheet 75, the protective module package 90, and the upper case 80 are sequentially stacked on the upper surface 71. The battery cell 70 is provided by sequentially stacking the lower insulating sheet 91 and the lower case 93 on the lower surface 72. The outer surface of the battery cell 70 may be covered and protected by the packaging label 95.

The battery cell 70 has an upper surface 71 and a lower surface 72, and the negative electrode tab 73 is electrically isolated from the positive electrode plate 74 formed on the upper surface 71 so as to protrude from the positive electrode plate 74. have. Of course, the positive electrode plate 74 is electrically connected to the positive electrode of the cell embedded in the battery cell 70, the negative electrode tab 73 is electrically connected to the negative electrode of the cell. For example, a lithium secondary battery such as a lithium ion battery, a lithium polymer battery, or the like may be used as the battery cell 70.

The upper insulating sheet 75 is attached to the upper surface 71 of the battery cell 70, and serves to prevent electrical short between the negative electrode tab 73 and the positive electrode plate 74 of the battery cell 70. The upper insulating sheet 75 is formed with a first opening 76 through which the negative electrode tab 73 can be exposed. A portion of the positive electrode plate 74 is exposed to the outside through the upper surface 71 of the battery cell 70 on one side of the upper insulating sheet 75, and the outside of the positive electrode of the protective module package 90 to the exposed portion of the positive electrode plate 74. Lead 78 is joined. In this case, various synthetic resins, such as polycarbonate (PC) and poly ethylene (PE), may be used as the material of the upper insulation sheet 75. The upper insulating sheet 75 may be implemented in the form of a rigid plate or a tape having flexibility.

The protective module package 90 is mounted on the upper insulating sheet 75 and is electrically connected to the negative electrode tab 73 and the positive electrode plate 74 of the battery cell 70. The protection module package 90 has a structure in which a chip-shaped protection circuit element is built in the package body 79. The protective module package 90 protrudes on both sides of the negative electrode lead 77 and the positive electrode lead 78, and the negative electrode lead 77 is formed by passing a positive temperature coefficient (PTC) element to the negative electrode tab 73. The anode outer lead 78 is bonded to the anode plate 74. The plurality of terminal pads 85 exposed to the openings 81 and 83 of the upper case 80 are exposed to the upper portion of the package body 79.

In this case, the negative electrode lead 77 may be bonded to the negative electrode tab 73 by a resistance welding method. The anode outer lead 78 may be bonded to the anode plate 74 by laser welding. The external leads 65 and 67 may be joined to the negative electrode tab 16 and the positive electrode plate 74 via ultrasonic welding or a conductive adhesive, respectively.

As described above, since the protection circuit module is implemented as the protection module package 90, the battery pack 300 according to another embodiment of the present invention can minimize the space occupied by the protection circuit module in the battery pack 300. Since the protection module package 90 has a protection circuit element embedded in a chip shape and the package body 79 may be manufactured in a plate shape by molding, the protection module package 90 may be implemented as a protection circuit module having a small thickness and a small size. .

The protection module package 90 is interposed between the battery cell 70 and the power supply unit or the portable terminal to provide protection functions of the battery pack 300 such as overcharge protection, overdischarge prevention, and overcurrent protection of the battery cell 70. Perform.

The upper case 80 is installed to be coupled to the upper portion of the battery cell 70 to cover the protection module package 90, and the openings 81 and 83 are connected to the plurality of terminal pads 85 of the protection module package 90. Each is formed to correspond. The openings 81 and 83 are formed through the upper surface of the upper case 80 to be connected to the portable terminal. The upper case 80 may be attached to the label sheet 97 in the groove 87 provided on one side of the upper surface. The upper case 80 may be formed with a groove or a protrusion that can be attached to and detached from the portable terminal. The upper case 80 may be manufactured by a molding method using a hard plastic material such as an epoxy resin.

The lower insulating sheet 91 is attached to the lower surface 72 of the battery cell 70. As the lower insulating sheet 91, the same material as the upper insulating sheet 75 may be used.

The lower case 93 is coupled to the lower portion of the battery cell 70 to cover the lower insulating sheet 91. The lower case 93 may be manufactured by a molding method using a hard plastic material such as an epoxy resin.

The packaging label 95 is attached to the outer side of the battery cell 70 to surround the outer side of the battery cell 70. At this time, the packaging label 95 is attached to surround portions of the upper case 80 and the lower case 93 extending to the upper end and the lower end of the battery cell 70.

In the present specification, the term 'battery' may refer to a battery cell connected to terminals B + and B- of FIG. 2, and the term 'battery pack' refers to a combination of the above battery and the circuit shown in FIG. 2. Can mean. The negative terminal of the battery may be, for example, the terminal B- of FIG. 2, and the negative terminal of the battery pack may be, for example, the terminal P- of FIG. 2.

As used herein, “current bypasses one MOSFET” may mean that the current does not flow through the one MOSFET but through another circuit path.

By using the embodiments of the present invention described above, those belonging to the technical field of the present invention will be able to easily make various changes and modifications without departing from the essential characteristics of the present invention. The content of each claim in the claims may be combined in another claim without citations within the scope of the claims.

Claims (13)

1. Battery charge / discharge protection device connected to the positive and negative terminals of the battery to form a battery pack,

   One MOSFET; And a protection IC controlling the single MOSFET,

   The source terminal of the one MOSFET is directly connected to the negative terminal of the battery, the drain terminal of the one MOSFET is characterized in that the negative terminal of the battery pack,

   Battery charge and discharge protection.
2. The method of claim 1,

   The first terminal of the protection IC is connected to the gate terminal to control the voltage of the gate terminal of the one MOSFET,

   A pair of diodes are opposed between the source terminal and the drain terminal such that current flowing into the drain terminal or the source terminal bypasses the MOSFET when the one MOSFET is controlled to be in an off state. Connected in series,

   Battery charge and discharge protection.
3. The battery charge / discharge protection device of claim 2, wherein the bypassed current is configured to flow through the protection IC.
4. battery; And a battery charge / discharge protection device connected to the positive and negative terminals of the battery.

   The battery charge and discharge protection device includes a MOSFET and a protection IC for controlling the MOSFET,

   The source terminal of the one MOSFET is directly connected to the negative terminal of the battery, the drain terminal of the one MOSFET is characterized in that the negative terminal of the battery pack,

   Battery pack.
5. The method of claim 4, wherein

   The first terminal of the protection IC is connected to the gate terminal to control the voltage of the gate terminal of the one MOSFET,

   When the one MOSFET is controlled to be in an off state, a pair of diodes are opposed to each other between the source terminal and the drain terminal such that current flowing into the drain terminal or the source terminal bypasses the MOSFET. Connected in series,

   Battery pack.
6. 6. The battery pack of claim 5 wherein the bypassed current is adapted to flow through the protection IC.
7. The source terminal is connected to the negative terminal of the battery, the drain terminal is a battery charge and discharge control IC that controls a MOSFET connected to the negative terminal of the battery pack including the battery,

   A first terminal for controlling a gate voltage of the one MOSFET so that no current flows through the one MOSFET when the charge or discharge of the battery is interrupted; And

    When the charging or discharging of the battery is interrupted, at least one pair of bypass terminals to bypass the first current flowing through the battery through the battery charge and discharge control IC,

   Battery charge / discharge control IC.
8. A battery protection IC that controls a transistor to block or conduct current flowing through a battery,

   Inner-transistor; And a control logic for generating a control signal for controlling the transistor and the inner-transistor.

   The control logic controls the transistor to prevent current from flowing through the transistor when the charging or discharging of the battery is interrupted, and the internal current such that the first current flowing through the battery is bypassed through the internal transistor. Designed to control the transistor,

   Battery charge / discharge control IC.
9. The control logic of claim 8, wherein the control logic controls the inner-transistor to prevent current from flowing through the inner-transistor when the charging or discharging of the battery is interrupted and then allowed again. To control the transistor such that a current flows through the transistor,

   Battery charge / discharge control IC.
10. The battery charge / discharge control IC of claim 8, wherein the inner-transistor and the transistor are MOSFETs.
11. The battery charge / discharge control IC of claim 10, wherein a first diode for bypassing the charging direction current and a second diode for bypassing the discharge direction current are connected between the source terminal and the drain terminal of the transistor.
12. A transistor for blocking or conducting current flowing through the battery; And

    An IC comprising an intra-transistor, and a control logic for generating a control signal for controlling the transistor and the intra-transistor;

    Including;

    The control logic controls the transistor so that no current flows through the transistor when the charging or discharging of the battery is interrupted, and the first current flowing through the battery is bypassed through the inner-transistor. To control the transistor,

    Battery charge and discharge control.
13. The control circuit of claim 12, wherein the control logic controls the inner-transistor so that no current flows through the inner-transistor when the charging or discharging of the battery is interrupted and then allowed again. And control the transistor such that a current flows through the transistor.

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