KR20220127722A - Battery system and operating method of electronic device including the smae - Google Patents

Abstract

The present invention relates to a battery system, and an operating method of an electronic device including the same. According to the present invention, the battery system comprises: a first battery cell selectively connected to a first output terminal and a second output terminal and having a first charge status; a second battery cell selectively connected to the first output terminal and the second output terminal and having a second charge status showing a lower charge level than that of the first charge status; a DC-DC converter including an input capacitor connected to the first output terminal and the second output terminal; and a switching circuit performing a first cell balancing operation to alternately connect the input capacitor to the first battery cell or the second battery cell or a second balancing operation to connect the input capacitor to the first battery based on the size of a load current. The present invention aims to provide a battery system and an operating method of an electronic device including the same, which are capable of extending the life of a plurality of battery cells.

Description

BATTERY SYSTEM AND OPERATING METHOD OF ELECTRONIC DEVICE INCLUDING THE SMAE

The technical idea of the present disclosure relates to a battery system, and more particularly, to a battery system for performing a cell balancing operation and an operating method of an electronic device including the same.

A portable electronic device, such as a mobile phone, includes a battery. As next-generation communication technology continues to evolve, the power required for data processing in a mobile phone is increasing. Accordingly, one battery pack includes a plurality of battery cells.

However, since the plurality of battery cells cannot have perfectly the same characteristics, as charging and discharging of the battery pack are repeated, an imbalance may occur in the state of charge between the battery cells. If charging and discharging of the battery pack are continuously repeated without suppressing such imbalance, the usable capacity of the battery pack is reduced and deterioration of battery cells included therein is accelerated.

SUMMARY The present disclosure provides a battery system capable of supplying power to a system load while simultaneously performing a cell balancing operation between battery cells by including a switching circuit, and an operating method of an electronic device including the same.

SUMMARY The present disclosure provides a battery system that extends the lifespan of a plurality of battery cells by performing a cell balancing operation in different modes according to a load current, and a method of operating an electronic device including the same.

In order to achieve the above object, the battery system according to an aspect of the present disclosure is selectively connected to a first output terminal and a second output terminal, a first battery cell having a first charge state, a first output terminal and a second battery cell selectively connected to the second output terminal, the second battery cell having a second state of charge indicating a lower charge level than the first state of charge, and an input capacitor connected to the first and second output terminals. A first cell balancing operation of alternately connecting an input capacitor to a first battery cell or a second battery cell or a second cell balancing operation of connecting an input capacitor to the first battery is performed based on the magnitudes of the converter and the load current a switching circuit that

The battery system according to another aspect of the present disclosure includes first to third battery cells selectively connected to a first output terminal and a second output terminal, respectively, and charging used for charging the first to third battery cells based on an external power source 1 to 3 battery cells by connecting in series the first to third battery cells with each other in series according to the presence or absence of a charging integrated circuit generating a current, and connecting at least one of the first to third battery cells to the first and second output terminals A DC-DC converter comprising: a switching circuit for performing a cell balancing operation with respect to a switching circuit; and an input capacitor connected to the first and second output terminals and providing a load current used as a power source of a load, the charging integrated circuit comprising: generate a current or a charging current having a magnitude determined based on a difference between the charging states of the first to third battery cells.

According to another aspect of the present disclosure, a method of operating an electronic device includes: simultaneously charging a plurality of battery cells by connecting a plurality of battery cells in series based on the presence or absence of a charging current provided to the plurality of battery cells; performing a first cell balancing operation or a second cell balancing operation based on a magnitude of a load current transferred from the Cell balancing between the first battery cell and the second battery cell is performed by transferring the voltage of the first battery cell having Cell balancing is performed between the first battery cell and the second battery cell by providing power to the system load.

According to an exemplary embodiment of the present disclosure, a battery system capable of supplying power to a system load while performing a cell balancing operation between battery cells and a method of operating an electronic device including the same may be provided.

According to an exemplary embodiment of the present disclosure, a battery system that extends the lifespan of a plurality of battery cells by performing a cell balancing operation in different modes according to a load current, and a method of operating an electronic device including the same may be provided.

1 is a diagram for describing an electronic device according to an exemplary embodiment of the present disclosure.
2 is a view for explaining a battery device according to an exemplary embodiment of the present disclosure.
3 is a diagram for describing a first cell balancing operation according to an exemplary embodiment of the present disclosure.
FIG. 4A is a circuit diagram exemplarily illustrating the first switch SW_1 of FIG. 2 .
4B is a circuit diagram exemplarily illustrating the second switch SW_2 of FIG. 2 .
5 is a diagram illustrating a battery device according to an exemplary embodiment of the present disclosure.
6 is a diagram illustrating an operation mode of a cell balancing operation according to an exemplary embodiment of the present disclosure.
7A and 7B are diagrams for explaining a first cell balancing operation in a first mode.
8A and 8B are diagrams for explaining a first cell balancing operation in a second mode.
9 is a diagram for describing a first cell balancing operation in a first mode and a second cell balancing operation in a third mode according to an exemplary embodiment of the present disclosure.
10 is a diagram for describing a second cell balancing operation in a fourth mode or a fifth mode according to an exemplary embodiment of the present disclosure.
11 is a diagram for describing a first cell balancing operation in a second mode and a second cell balancing operation in a fourth mode according to an exemplary embodiment of the present disclosure.
12 is a flowchart illustrating a method of operating an electronic device according to an exemplary embodiment of the present disclosure.
13 is a flowchart illustrating a method of operating an electronic device according to an exemplary embodiment of the present disclosure.
14 is a block diagram illustrating an electronic device 1000 according to an exemplary embodiment of the present disclosure.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a diagram for describing an electronic device according to an exemplary embodiment of the present disclosure.

Referring to FIG. 1 , an electronic device 1 may include a battery system 10 and a system load 20 . The battery system 10 may receive a charge input CHGIN and provide power to the system load 20 . The electronic device 1 is a smart phone, a tablet PC (Personal Computer), a mobile phone, a PDA (Personal Digital Assistant), a laptop (labtop), a wearable device, a GPS (Global Positional system) device, an e-book terminal , a digital broadcasting terminal, an MP3 player, a mobile device such as a digital camera. Furthermore, the electronic device 1 may be a device for performing the Internet of Things or a device included in an electric vehicle.

The battery system 10 may include a charger integrated circuit (charger IC) 100 , a battery device 200 , and a direct-current (DC)-direct-current (DC) converter 300 .

The charging integrated circuit 100 may be referred to as a battery charger. The charging integrated circuit 100 may be implemented as an integrated circuit chip, and may be mounted on a printed circuit board. The charging integrated circuit 100 may receive the charging input CHGIN and output the charging current I_CH for charging the battery device 200 . For example, the charging input CHGIN may be a charging current having a constant value in a constant current (CC) section for charging the battery device 200 , and a charging voltage having a constant value in a constant voltage (CV) section. can be

In some embodiments, the charging integrated circuit 100 may be connected to a travel adapter (TA) to receive a charging input CHGIN from the TA (not shown). The TA (not shown) may convert power supplied from AC 110 to 220V, which is household power, or other power supply means (eg, a computer) into DC power required for charging the battery and provide it to the electronic device 1 . In an exemplary embodiment, the charging integrated circuit 100 may be connected to an auxiliary battery (not shown) and charge the battery device 200 using DC power received from the auxiliary battery (not shown). In addition, the charging integrated circuit 100 may be connected to a wireless charging circuit (not shown) or configured to include a wireless charging circuit (not shown) to receive a charging input CHGIN from the wireless charging circuit (not shown). .

In some embodiments, the charging integrated circuit 100 may be a switching charger or a linear charger. In some embodiments, the charging integrated circuit 100 has an under-voltage lockout (UVLO) function, an over-current protection (OCP) function, an over-voltage protection (over-voltage lockout) function, to operate properly even under power saving conditions. voltage protection (OVP) function, soft-start function to reduce inrush current, foldback current limit function, Hiccup Mode function for short circuit protection, overheat protection function It may further include a circuit or block supporting at least one function among various functions such as -temperature protection, OTP) function.

The battery device 200 may be embedded in the electronic device 1 or may be detachable from the electronic device 1 . In some embodiments, the battery device 200 may be a multi-cell battery including a plurality of battery cells. In some embodiments, the battery device 200 may be a single cell battery including one battery cell. The battery device 200 may be referred to as a battery pack.

The battery device 200 may include first and second battery cells 210 and 220 . The first and second battery cells 210 and 220 may have different states of charge (SOC). For example, the first battery cell 210 may have a first state of charge, and the second battery cell 220 may have a second state of charge lower than the first state of charge. The battery device 200 may receive the charging current I_CH, and the first and second battery cells 210 and 220 may be charged based on the charging current I_CH.

The battery device 200 may include a switching circuit 230 and a control circuit 240 . The switching circuit 230 is configured such that the first and second battery cells 210 and 220 are connected in parallel to each other based on the control signal CS, or the first and second battery cells 210 and 220 are connected in series with each other. It can be configured to be The control circuit 240 may generate the control signal CS based on the presence or absence of the charging current I_CH and the magnitude of the load current I_L.

In some embodiments, the control circuit 240 may control the switching circuit 230 to connect the first and second battery cells 210 and 220 in series with each other based on the presence or absence of the charging current I_CH. In some embodiments, the control circuit 240 switches to perform a first cell balancing operation or a second cell balancing operation for the first and second battery cells 210 and 220 based on the magnitude of the load current I_L The circuit 230 may be controlled. The cell balancing operation may refer to an operation of uniformly adjusting the state of charge of battery cells having different state of charge.

The switching circuit 230 may perform a cell balancing operation on the first battery cell 210 and the second battery cell 220 . Specifically, when the magnitude of the load current I_L is equal to or smaller than the first threshold level I_th1 , the switching circuit 230 performs a first cell balancing operation, and the magnitude of the load current I_L becomes the first threshold If it is greater than the level I_th1, a second cell balancing operation may be performed.

During the first cell balancing operation, the switching circuit 230 alternately connects the input capacitor C_in to the first battery cell 210 and the second battery cell 220 according to the switching frequency fsw, thereby performing a cell balancing operation. can be performed. During the first period of the switching period Tsw, when the input capacitor C_in is connected to the first battery cell 210 , the input capacitor C_in may be charged by the first battery cell 210 . During the second period of the switching period Tsw, when the input capacitor C_in is connected to the second battery cell 220 , the second battery cell 220 may be charged by the input capacitor C_in. That is, the voltage of the first battery cell 210 may be transferred to the second battery cell 220 during the switching period Tsw.

During the second cell balancing operation, the switching circuit 230 applies the first battery cell 210 to the input capacitor until the state of charge of the first battery cell 210 becomes the same as the state of charge of the second battery cell 220 . You can connect to (C_in). The voltage of the input capacitor C_in may be transferred to the output capacitor C_out through the conversion circuit 310 , and the system load 20 may receive power from the output capacitor Cout. Accordingly, the state of charge of the battery cell connected to the input capacitor C_in may be lowered.

The switching circuit 230 may perform the cell balancing operation by transferring the voltage of the first battery cell 210 to the first battery cell 210 through the input capacitor C_in during the first cell balancing operation, and During the cell balancing operation, the cell balancing operation may be performed by connecting the first battery cell 210 to the input capacitor C_in.

The DC-DC converter 300 may include an input capacitor C_in, an output capacitor C_out, and a conversion circuit 310 . The conversion circuit 310 may generate the voltage of the output capacitor C_out by boosting or stepping down the voltage of the input capacitor C_in. The system load 20 may operate using power supplied from the output capacitor C_out.

The system load 20 may be chips or modules included in the electronic device 1 , for example, a modem, an application processor, a memory, a display, and the like. For example, the system load 20 may be an operation block, a function block, or an IP block included in the electronic device 1 , for example, a multimedia block in an application processor, a memory controller, or the like. The system load 20 may also be referred to as a consuming block or load.

Since the electronic device 1 according to an exemplary embodiment of the present disclosure may perform a cell balancing operation using the input capacitor C_in of the DC-DC converter 300, a separate capacitor for the cell balancing operation is provided. This may not be done, and the degree of integration of the electronic device 1 may be improved.

The switching circuit 230 according to an exemplary embodiment of the present disclosure is configured such that the first and second battery cells 210 and 220 are connected in series with each other depending on the presence or absence of the charging current I_CH, whereby the first and second battery cells ( 210 and 220) can be charged at the same time.

The switching circuit 230 according to an exemplary embodiment of the present disclosure provides power to the system load 20 and simultaneously provides power to the system load 20 by performing a first cell balancing operation or a second cell balancing operation according to the magnitude of the load current I_L. A cell balancing operation may be performed on the first and second battery cells 210 and 220 .

2 is a view for explaining a battery device according to an exemplary embodiment of the present disclosure. 3 is a diagram for describing a first cell balancing operation according to an exemplary embodiment of the present disclosure.

Referring to FIG. 2 , the battery device 200 may be connected to the charging integrated circuit 100 through the first and second input terminals P1 and P2 and DC through the first and second output terminals P3 and P4 . It may be connected to the input capacitor C_in included in the -DC converter 300 . The battery device 200 may receive the charging current I_CH through the first input terminal P1 and output the load current I_L through the first output terminal P3 . FIG. 2 may be described with reference to FIG. 1 .

The switching circuit 230 may include first to fifth switches SW_1 to SW_5 . The first switch SW_1 may connect the first battery cell 210 and the second battery cell 220 in series. The second switch SW_2 may connect one end of the first battery cell 210 to the first input terminal P1 and the first output terminal P3 . The third switch SW_3 may connect one end of the second battery cell 220 to the first input terminal P1 and the first output terminal P3 . The fourth switch SW_4 may connect the other end of the first battery cell 210 to the second output terminal P4 . The fifth switch SW_5 may connect the other end of the second battery cell 220 to the second output terminal P4 .

When the charging current I_CH exists, that is, when the battery device 200 is charged, the first switch SW_1 is turned on so that the first and second battery cells 210 and 220 can be simultaneously charged.

The switching circuit 230 may perform a first cell balancing operation or a second cell balancing operation according to the magnitude of the load current I_L. Specifically, when the magnitude of the load current I_L is equal to or smaller than the first threshold level I_th1 , the switching circuit 230 performs a first cell balancing operation, and the magnitude of the load current I_L becomes the first threshold If it is greater than the level I_th1, a second cell balancing operation may be performed.

2 and 3 , during the first balancing operation, the first battery cell 210 and the second battery cell 220 alternately the first and second output terminals P3 and P4 according to the switching frequency fsw. ) can be connected to Specifically, within the switching period Tsw, a first period (period 1) in which the first battery cell 210 is connected to the first and second output terminals P3 and P4 and the second battery cell 220 are connected to the first and a second period (period 2) connected to the second output terminals P3 and P4. The lengths of the first section and the second section may each correspond to a half of the switching period Tsw.

During the first period, the second switch SW_2 and the fourth switch SW4 are turned on, and the third switch SW_3 and the fifth switch SW_5 are turned off, so that the first battery cell 210 is It may be connected to the first and second output terminals P3 and P4. During the second period, the third switch SW_3 and the fifth switch SW5 are turned on, and the second switch SW_2 and the fourth switch SW_4 are turned off, so that the second battery cell 220 is It may be connected to the first and second output terminals P3 and P4.

Through the first balancing operation, the charging state of the first battery cell 210 and the charging state of the second battery cell 220 may be the same.

During the second balancing operation, the first battery cell 210 is connected to the first and second output terminals P3 and P4, and the second battery cell 220 is connected to the first and second output terminals P3 and P4. it may not be Specifically, during the second cell balancing operation, the second switch SW_2 and the fourth switch SW_4 may be turned on, and the third switch SW_3 and the fifth switch SW_5 may be turned off. For convenience of explanation, it has been described that the first battery cell 210 is connected to the first and second output terminals P3 and P4 during the second balancing operation, but during the second balancing operation, the first and second battery cells A battery cell having a higher state of charge among the 210 and 220 may be connected to the first and second output terminals P3 and P4 .

FIG. 4A is a circuit diagram exemplarily illustrating the first switch SW_1 of FIG. 2 , and FIG. 4B is a circuit diagram exemplarily illustrating the second switch SW_2 of FIG. 2 .

2 and 4A , the first switch SW_1 may include a transistor TR and a diode D. As shown in FIG. The transistor TR may be an N-channel metal oxide semiconductor (NMOS) transistor driven by the control signal CS. For example, the transistor TR may include a source connected to one end of the first battery cell 210 , a gate to which the control signal CS is applied, and a drain connected to the other end of the second battery cell 220 . can However, the present disclosure is not limited thereto, and the transistor TR may be implemented as a P-channel metal oxide semiconductor (PMOS) transistor. The diode D may be a parasitic diode of the transistor TR, and the first switch SW_1 may be a unidirectional switch that transmits current only in a direction from a source to a drain.

Referring to FIG. 4B , the second switch SW_2 may include first and second transistors TR_1 and TR_2 , and first and second diodes D_1 and D_2 . The first and second transistors TR_1 and TR_2 may be NMOS transistors driven by the first and second control signals CS_1 and CS_2, respectively. For example, the first transistor TR_1 may include a drain connected to the first input terminal P1 , a gate to which the first control signal CS_1 is applied, and a source connected to the source of the second transistor TR_2 . can The second transistor TR_2 may include a source connected to the source of the first transistor TR_1 , a gate to which the second control signal CS_2 is applied, and a drain connected to the first output terminal P3 . However, the present disclosure is not limited thereto, and the first and second transistors TR_1 and TR_2 may be implemented as P-channel metal oxide semiconductor (PMOS) transistors. The second switch SW_2 may be a bidirectional switch that transfers current in both directions. The third to fifth switches SW_3 to SW_5 may be implemented in the same way as the second switch SW_2 .

5 is a diagram illustrating a battery device according to an exemplary embodiment of the present disclosure.

Referring to FIG. 5 , the battery device 500 may include first to third battery cells 510 to 530 . However, the number of battery cells included in the battery device 500 is not limited thereto.

The state of charge of the first battery cell 510 may be referred to as a first state of charge SOC1 , the state of charge of the second battery cell 520 may be referred to as a second state of charge SOC2 , and the third state of charge may be referred to as a third state of charge SOC1 . The state of charge of the battery cell 530 may be referred to as a third state of charge SOC3 . When the cell balancing operation starts, the first state of charge SOC1 may indicate the most charged state, and the second state of charge SOC2 may indicate the least charged state.

The switching circuit 540 may include first to eighth switches SW_1 to SW_8 . The first switch SW_1 may selectively connect the other end of the first battery cell 510 and one end of the third battery cell 530 , and the second switch SW_2 is the other end of the third battery cell 530 . The terminal and one end of the second battery cell 520 may be selectively connected. The switching circuit 540 may be configured such that the first to third battery cells 510 to 530 are connected in series by turning on the first and second switches SW_1 and SW_2 depending on the presence or absence of the charging current I_CH. have. Accordingly, when the charging current I_CH is present, the first and second switches SW_1 and SW_2 are turned on so that the first to third battery cells 510 to 530 may be simultaneously charged.

The third switch SW_3 may selectively connect one end of the first battery cell 510 to the first input terminal P1 and the first output terminal P3 . The fourth switch SW_4 may selectively connect one end of the third battery cell 530 to the first output terminal P3 . The fifth switch SW_5 may selectively connect one end of the second battery cell 520 to the first output terminal P3 . The sixth switch SW_6 may selectively connect the other end of the first battery cell 510 to the second output terminal P4 . The seventh switch SW_7 may selectively connect the other end of the third battery cell 530 to the second output terminal P4 . The eighth switch SW_8 may selectively connect the other end of the second battery cell 520 to the second output terminal P4 .

The switching circuit 540 may perform a cell balancing operation on the first battery cell 510 having the highest initial state of charge and the second battery cell 520 having the lowest initial state of charge. The cell balancing operation for the first battery cell 510 and the second battery cell 520 may be the same as the method described above with reference to FIGS. 2 and 3 .

In some embodiments, the switching circuit 540 may perform a cell balancing operation using two or more battery cells connected in series. For example, by turning on the first switch SW_1 to connect the first battery cell 510 and the third battery cell 530 in series, the first and third battery cells 510 and 530 connected in series The first cell balancing operation or the second cell balancing operation may be performed so that the sum of the state of charge of , and the state of charge of the second battery cell 520 become the same. Specifically, during the first cell balancing operation, during the first period of FIG. 3 , the second, third, and seventh switches SW_2 , SW_3 , and SW_7 are turned on, and during the second period, the second, fifth And when the eighth switches SW_2, SW_5, and SW_8 are turned on, the sum of the charging states of the first and third battery cells 510 and 530 and the charging state of the second battery cell 520 may be the same. . Alternatively, during the second cell balancing operation, the second, third and third battery cells 520 and the sum of the charge states of the first and third battery cells 510 and 530 become the same until the second battery cell 520 becomes the same. 7 switches SW_2, SW_3, and SW_7 may be maintained in a turned-on state.

6 is a diagram illustrating an operation mode of a cell balancing operation according to an exemplary embodiment of the present disclosure. FIG. 6 may be described with reference to FIG. 5 .

Referring to FIG. 6 , the switching circuit 540 may perform a first cell balancing operation 1 or a second cell balancing operation 2 . The first cell balancing operation may be performed when the load current I_L is equal to or lower than the first threshold level I_th1, and the second cell balancing operation is performed when the load current I_L is greater than the first threshold level I_th1. case can be performed. It may be assumed that a cell balancing operation is performed between the first battery cell 510 and the second battery cell 520 . When the cell balancing operation starts, it may be assumed that the state of charge of the first battery cell 510 is greater than that of the second battery cell 520 .

The first cell balancing operation may be performed in a first mode and a second mode. The first mode may mean a first cell balancing operation performed in a state in which the battery device 500 is not charged, that is, a state in which there is no charging current I_CH, and in the second mode, the battery device 500 is charged. This may mean a first cell balancing operation performed in a state where the charging current I_CH exists.

In the second mode, the charging integrated circuit 100 may output the charging current I_CH having the first current level I_CH1 . The first current level I_CH1 may be expressed as [Equation 1].

Here, I_bal may mean a balancing current transferred from the first battery cell 510 to the second battery cell 520 during the switching period Tsw, I_CHMAX may mean a maximum charging current, and SOC_H is the most It may mean a high state of charge, that is, a state of charge of the first battery cell 510 . The state of charge may have a value between 0 and 1. The balancing current I_bal may be proportional to a difference between the charging state of the first battery cell 510 and the charging state of the second battery cell 520 . For example, when the difference between the charging state of the first battery cell 510 and the charging state of the second battery cell 520 is relatively large, the balancing current I_bal may be relatively large. As the cell balancing operation is performed, the difference between the charging states of the first battery cell 510 and the second battery cell 520 may decrease, so that the balancing current I_bal may gradually decrease.

에 대응될 수 있다.According to [Equation 1], when the charge state of the first battery cell 510 is 0, the first current level I_CH1 may be the maximum charge current I_CHMAX, and the charge state of the first battery cell 510 is In the buffered state, that is, 1, the first current level I_CH1 is

can correspond to

The second cell balancing operation may be performed in a third mode to a fifth mode. The third mode may mean a second cell balancing operation performed in a state in which the battery device 500 is not charged, that is, in a state in which there is no charging current I_CH, and the fourth and fifth modes are the battery device 500 . ) may refer to a charging state, that is, a second cell balancing operation performed in a state in which the charging current I_CH is present. When the load current I_L is greater than the first threshold level and is equal to or less than the second threshold level, the second cell balancing operation may be performed in a fourth mode, and the load current I_L is greater than the second threshold level In this case, the second cell balancing operation may be performed in the fifth mode.

In the fourth mode, the charging integrated circuit 100 may output the charging current I_CH having the second current level I_CH2 . The second current level I_CH2 may be expressed as [Equation 2].

Here, SOC_H.init may mean the highest initial state of charge, that is, the initial state of charge of the second battery cell 520 , and SOC_M.init may indicate the intermediate initial state of charge, that is, of the third battery cell 530 . It may mean an initial state of charge, and SOC_L.init may mean the lowest initial state of charge, that is, the initial state of charge of the second battery cell 520 . The state of charge may have a value between 0 and 1.

In the fifth mode, the charging integrated circuit 100 may output the charging current I_CH having the third current level I_CH3 . The third current level I_CH3 may be equal to the current level of the maximum charging current I_CHMAX.

7A and 7B are diagrams for explaining a first cell balancing operation in a first mode. Specifically, FIG. 7A shows a switching circuit corresponding to the first section of FIG. 3 , and FIG. 7B shows a switching circuit corresponding to the second section of FIG. 3 .

3 and 7A , during the first period, the first battery cell 510 may transfer the charging charge Qs to the input capacitor C_in. The charge charge Qs may be expressed as [Equation 3].

Here, I_bal may mean a balancing current transferred from the first battery cell 510 to the second battery cell 520 during the switching period Tsw, and I_L may mean a load current.

3 and 7B , during the second period, the input capacitor C_in may transfer the discharge charge Qt to the second battery cell 520 . The discharge charge Qt may be expressed as [Equation 4].

만큼의 전하가 제1 배터리 셀(510)에서 제2 배터리 셀(520)로 전달될 수 있다.Referring to [Equation 3] and [Equation 4], during the switching period (Tsw)

The amount of charge may be transferred from the first battery cell 510 to the second battery cell 520 .

On the other hand, when the discharge charge Qt has a negative value, the charge is not transferred from the input capacitor C_in to the second battery cell 520 but from the second battery cell 520 to the input capacitor C_in. Charge can be transferred. Accordingly, in order to perform the first cell balancing operation, the discharge charge Qt must be equal to or greater than zero. That is, since the first cell balancing operation may be performed when I_L ≤ 2*I_bal, the first threshold level I_th1 of FIG. 6 may correspond to 2*I_bal.

8A and 8B are diagrams for explaining a first cell balancing operation in a second mode. Specifically, FIG. 8A shows a switching circuit corresponding to the first section of FIG. 3 , and FIG. 8B shows a switching circuit corresponding to the second section of FIG. 3 .

8A and 8B , when the switching circuit 540 performs the first cell balancing operation of the second mode, the first and second switches SW_1 and SW2 may be turned on. Accordingly, the first to third battery cells 510 to 530 may be simultaneously charged by the charging current I_CH having the first current level I_CH1 .

에 대응될 수 있다.As described above with reference to Equation 1, as the first battery cell 510 is charged, the first current level I_CH1 may gradually decrease. When the first battery cell 510 is fully charged, the first current level I_CH1 is

can correspond to

이 되는 경우, 제1 배터리 셀(510)의 충전은 중단될 수 있다.Since the charge Qs discharged from the first battery cell 510 during the first period of FIG. 3 can be expressed as Equation 3, when the first battery cell 510 is fully charged, the first current level I_CH1 this

In this case, charging of the first battery cell 510 may be stopped.

이 되는 경우, 제2 배터리 셀(520)은 충전될 수 있다.On the other hand, since the charge Qt charged in the second battery cell 520 during the second period of FIG. 3 can be expressed as [Equation 4], when the first battery cell 510 is fully charged, the first current level ( I_CH1) is

In this case, the second battery cell 520 may be charged.

As the voltage difference between the first battery cell 510 and the second battery cell 520 decreases, the balancing current I_bal may decrease. As described above with reference to FIGS. 7A and 7B , when the balancing current I_bal decreases, the first threshold level I_th1 decreases, so that the load current I_L may be greater than the first threshold level I_th1. Accordingly, the switching circuit 540 may perform a second cell balancing operation.

9 is a diagram for describing a first cell balancing operation in a first mode and a second cell balancing operation in a third mode according to an exemplary embodiment of the present disclosure. That is, FIG. 9 is a view for explaining the first and second cell balancing operations when there is no charging current I_CH. FIG. 9 may be described with reference to FIG. 5 . The first battery cell 510 may have a first state of charge SOC_1 , the second battery cell 520 may have a second state of charge SOC_2 , and the third battery cell 530 may have a third state of charge SOC_1 . It may have a state of charge (SOC_3).

At an initial time point t0, the first charging state SOC_1 is the first initial level SOC_1.init, the second charging state SOC_2 is the second initial level SOC_2.init, and the third charging state SOC_3 ) may be the third initial level (SOC_3.init). Since the load current I_L is less than the first threshold level I_th1 at the initial time point t0, the first cell balancing operation in the first mode may be performed. Since the description of the first cell balancing operation of the first mode has been described above with reference to FIGS. 7A and 7B , it will be omitted. By the first cell balancing operation, cell balancing between the first battery cell 510 and the second battery cell 520 may be performed. As the difference between the first state of charge SOC_1 and the second state of charge SOC_2 decreases, the size of the first threshold level I_th1 may gradually decrease.

At the first time point t1 , the load current I_L may be greater than the first threshold level I_th1 , and the second cell balancing operation in the third mode may be performed. During the second cell balancing operation of the third mode, a battery cell having the highest state of charge may be connected to the input capacitor C_in. Accordingly, at a first time point t1 , the first battery cell 510 having the highest state of charge may be connected to the input capacitor C_in. Specifically, both ends of the first battery cell 510 may be connected to the first and second output terminals P3 and P4 , and both ends of the second and third battery cells 520 and 530 are connected to the first and second output terminals P3 and P4 . It may not be connected to the output terminals P3 and P4. That is, the third and sixth switches SW_3 and SW_6 may be turned on, and the first, 2, 4, 5, 7, and 8 switches SW_1, SW_2, SW_4, SW_5, SW_7, SW_8 may be turned off. can

At a second time point t2 , both the first state of charge SOC_1 and the second state of charge SOC_2 may have a balance level SOC_bal. At a second time point t2 , the switching circuit 540 may perform a second cell balancing operation using the third battery cell 530 having the highest state of charge. Specifically, at the second time point t2 , the third battery cell 530 may be connected to the input capacitor C_in. Both ends of the third battery cell 530 may be connected to the first and second output terminals P3 and P4, and both ends of the first and second battery cells 510 and 520 are connected to the first and second output terminals (P3 and P4). P3, P4) may not be connected. That is, the fourth and seventh switches SW_4 and SW_7 may be turned on, and the first, second, 3, 5, 6, and 8 switches SW_1, SW_2, SW_3, SW_5, SW_6, SW_8 may be turned off. can

At a third time point t3 , all of the charging states SOC_1 to SOC_3 of the first to third battery cells 510 to 530 may have a balance level SOC_bal.

10 is a diagram for describing a second cell balancing operation in a fourth mode or a fifth mode according to an exemplary embodiment of the present disclosure. FIG. 10 may be described with reference to FIG. 5 .

Referring to FIG. 10 , during the second cell balancing operation in the fourth and fifth modes, since the charging current I_CH exists, all of the first to third charging states SOC_1 to SOC_3 may increase. However, during the second cell balancing operation, since the first battery cell 510 having the highest state of charge is connected to the input capacitor C_in, the first state of charge SOC_1 corresponds to the second and third state of charge SOC_2 and SOC_3 . may increase more slowly.

Meanwhile, if the third battery cell 530 is fully charged before the levels of the first state of charge SOC_1 and the level of the second state of charge SOC_2 become the same, the first battery cell 510 and the second battery cell 520 . In the charging process for , the third battery cell 530 may be overcharged. Therefore, before the third state of charge SOC_3 indicates full charge, the levels of the first state of charge SOC_1 and the level of the second state of charge SOC_2 may be equal to each other. That is, referring to FIG. 10 , it may arrive at a second time point t2 after a first time point t1 .

The time t11 from the initial time point t0 to the first time point t1 may be expressed as [Equation 5], and the time t22 from the initial time point t0 to the second time point t2 is [Equation 5] 6] can be expressed as

Referring to [Equation 5], a time t11 is a charge corresponding to the difference between SOC_1.int, which is the initial level of the first state of charge (SOC_1), and SOC_2.int, which is the initial level of SOC_2.int of the second battery cell 520 . may correspond to the time consumed by the load current I_L.

Referring to [Equation 6], a time t22 may correspond to a time in which the charge required until the third battery cell 530 is fully charged is charged by the maximum charging current I_CHMAX.

That is, assuming that the battery device 500 is charged with the maximum charging current I_CHMAX, in order to prevent overcharging of the third battery cell 530, the time t11 may be shorter than the time t22, so the load current I_L ) may be the same as [Equation 7].

일 수 있고, 최대 충전 전류(I_CHMAX)로 배터리 장치(500)를 충전하기 위해서는 부하 전류(I_L)가 제2 임계 레벨(I_th2)보다 커야할 수 있다.That is, the second threshold level I_th2 of FIG. 6 is

, and in order to charge the battery device 500 with the maximum charging current I_CHMAX, the load current I_L may be greater than the second threshold level I_th2.

11 is a diagram for describing a first cell balancing operation in a second mode and a second cell balancing operation in a fourth mode according to an exemplary embodiment of the present disclosure. That is, FIG. 11 is a view for explaining the first and second cell balancing operations when there is a charging current I_CH. 11 may be described with reference to FIG. 5 .

Since the load current I_L is less than the first threshold level I_th1 at the initial time point t0, the first cell balancing operation of the second mode may be performed. Since the description of the first cell balancing operation of the second mode has been described above with reference to FIGS. 8A and 8B , it will be omitted. By the first cell balancing operation, cell balancing between the first battery cell 510 and the second battery cell 520 may be performed. As the difference between the first state of charge SOC_1 and the second state of charge SOC_2 decreases, the size of the first threshold level I_th1 may gradually decrease. Meanwhile, while the first cell balancing operation of the second mode is being performed, the charging current I_CH may have the first current level I_CH1 described above through Equation (1).

At the first time point t1 , the load current I_L may be greater than the first threshold level I_th1 , and the second cell balancing operation in the fourth mode may be performed. During the second cell balancing operation in the fourth mode, the first battery cell 510 having the highest state of charge may be connected to the input capacitor C_in. Specifically, both ends of the first battery cell 510 may be connected to the first and second output terminals P3 and P4 , and both ends of the second and third battery cells 520 and 530 are connected to the first and second output terminals P3 and P4 . It may not be connected to the output terminals P3 and P4. That is, the third and sixth switches SW_3 and SW_6 may be turned on, and the first, 2, 4, 5, 7, and 8 switches SW_1, SW_2, SW_4, SW_5, SW_7, SW_8 may be turned off. can The charging current I_CH at the first time point t1 is the second current level I_CH2 calculated through [Equation 2] based on the first to third charge states SOC_1 to SOC_3 at the first time point t1. ) can be determined.

At the second time point t2 , both the first state of charge SOC_1 and the second state of charge SOC_2 may be at the balance level SOC_bal. The switching circuit 540 may perform a second cell balancing operation using the third battery cell 530 having the highest state of charge at the second time point t2 . That is, at the second time point t2 , the third battery cell 530 may be connected to the input capacitor C_in. Specifically, both ends of the third battery cell 530 may be connected to the first and second output terminals P3 and P4 , and both ends of the first and second battery cells 510 and 520 are connected to the first and second output terminals P3 and P4 . It may not be connected to the output terminals P3 and P4. That is, the fourth and seventh switches SW_4 and SW_7 may be turned on, and the first, second, 3, 5, 6, and 8 switches SW_1, SW_2, SW_3, SW_5, SW_6, SW_8 may be turned off. can The charging current I_CH may be determined as the second current level I_CH2 calculated through Equation 2 based on the first to third charging states SOC_1 to SOC_3 at the second time point t2 . Referring to [Equation 2], since the third charge state SOC_3 is fully charged at the second time point t2, SOC_H.int is 1, and both the first and second charge states are balanced at the second time point t2. Since the level SOC_bal, the second current level I_CH2 may be equal to the load current I_L.

At the third time point t3 , all of the charging states SOC_1 to SOC_3 of the first to third battery cells 510 to 530 may indicate full charge.

12 is a flowchart illustrating a method of operating an electronic device according to an exemplary embodiment of the present disclosure.

Referring to FIG. 12 , the method of operating an electronic device may include a plurality of steps S1210 and S1220. 12 may be described with reference to FIG. 5 .

In operation S1210 , the switching circuit 540 may connect the first to third battery cells 510 to 530 in series with each other based on the presence or absence of the charging current I_CH. Specifically, when there is a charging current I_CH, the switching circuit 540 may turn on the first and second switches SW_1 and SW_2, and when there is no charging current I_CH, the switching circuit 540 is The first and second switches SW_1 and SW_2 may be turned off.

In step S1220 , the switching circuit 540 transfers the voltage of the first battery cell 510 to the second battery cell 520 based on the magnitude of the load current I_L, thereby forming the first battery cell 510 and the second battery cell 520 . A cell between the first battery cell 510 and the second battery cell 520 by generating a load current by using the first cell balancing operation to perform cell balancing between the battery cells 520 or the first battery cell 510 . A second cell balancing operation performing balancing may be performed. Specifically, the switching circuit 540 may perform a first cell balancing operation when the load current I_L is equal to or less than the first threshold level I_th1, and the load current I_L is set at the first threshold level I_th1. ), the second cell balancing operation may be performed.

13 is a flowchart illustrating a method of operating an electronic device according to an exemplary embodiment of the present disclosure. Referring to FIG. 13 , the method of operating an electronic device may include a plurality of steps S1310 to S1380 . FIG. 13 may be described with reference to FIG. 1 or FIG. 5 .

In operation S1310 , the charging integrated circuit 100 may monitor the magnitude of the load current I_L. The charging integrated circuit 100 may determine the magnitude of the charging current I_CH based on the magnitude of the load current I_L. In the charging integrated circuit 100 , the magnitude of the load current I_L may be compared with the first threshold level I_th1 and the second threshold level I_th2 . The second threshold level I_th2 may be greater than the first threshold level I_th1.

In step S1320, if the magnitude of the load current I_L is greater than the first threshold level (I_th1), step S1340 may be performed, and if the magnitude of the load current (I_L) is not greater than the first threshold level (I_th1), step S1330 is performed can be performed. In step S1330, if the magnitude of the load current I_L is greater than the second threshold level I_th2, step S1350 may be performed, and if the magnitude of the load current I_L is not greater than the second threshold level I_th2, step S1360 is performed. can be performed.

In operation S1340 , the charging integrated circuit 100 may output a charging current I_CH proportional to the balancing current I_bal. Specifically, the charging integrated circuit 100 may output the charging current I_CH having the first current level I_CH1 according to Equation 1 .

In operation S1370 , the switching circuit 540 may perform a first cell balancing operation of transferring the voltage of the first battery cell 510 to the second battery cell 520 using the input capacitor C_in.

In operation S1350 , the charging integrated circuit 100 may output a charging current I_CH proportional to the load current I_L. In detail, the charging integrated circuit 100 may output the charging current I_CH having the second current level I_CH2 according to Equation (2).

In operation S1360 , the charging integrated circuit 100 may output a maximum charging current I_CHMAX.

In operation S1380 , the switching circuit 540 may perform a second cell balancing operation between the battery cells by connecting the battery cell having the highest state of charge to the input capacitor C_in.

14 is a block diagram illustrating an electronic device 1000 according to an exemplary embodiment of the present disclosure.

Referring to FIG. 14 , the electronic device 1000 may include a charging integrated circuit 1100 , a battery device 1200 , a PMIC 1300 , and an application processor 1400 . The electronic device 1000 may receive power from the outside and include a charging integrated circuit 1100 for charging the battery device 1200 . The charging integrated circuit 1100 and the battery device 1200 may be implemented according to various embodiments illustrated in FIGS. 1 to 13 .

The PMIC 1300 may receive a battery voltage and manage power required to drive the application processor 1400 . Also, the PMIC 1300 may be implemented to generate or manage voltages required for internal components of the electronic device 1000 . According to embodiments, the electronic device 1000 may include a plurality of PMICs including the PMIC 1300 . In an embodiment, the PMIC 1300 may receive a battery voltage from the battery device 1200 . In one embodiment, the PMIC 1300 may receive the system voltage through the charging integrated circuit 1100 . In an embodiment, the PMIC 1300 may directly receive the charging input CHGIN.

The application processor 1400 may control the electronic device 1000 as a whole. In an embodiment, the application processor 1400 may control the charging integrated circuit 1100 and the battery device 1200 . For example, the charging integrated circuit 1100 and the battery device 1200 may be controlled to perform a first cell balancing operation having the first mode and the second mode, and a second cell balancing operation having the third to fifth modes. have. In an embodiment, when the electronic device 1000 is connected to the TA, the application processor 1400 may communicate with the TA and adjust the charging input CHGIN output from the TA. In an embodiment, the application processor 1400 may be implemented as a system-on-chip including one or more intelligent properties (IPs).

Exemplary embodiments have been disclosed in the drawings and specification as described above. Although the embodiments have been described using specific terms in the present specification, these are used only for the purpose of explaining the technical idea of the present disclosure and not used to limit the meaning or the scope of the present disclosure described in the claims. . Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present disclosure should be defined by the technical spirit of the appended claims.

Claims (20)

A battery system for providing power to a load based on a load current, the battery system comprising:
a first battery cell selectively connected to the first output terminal and the second output terminal and having a first state of charge;
a second battery cell selectively connected to the first output terminal and the second output terminal, the second battery cell having a second state of charge indicating a lower charge level than the first state of charge;
a DC-DC converter including an input capacitor connected to the first and second output terminals; and
A first cell balancing operation of alternately connecting the input capacitor to the first battery cell or a second battery cell or a second cell balancing operation of connecting the input capacitor to the first battery based on the magnitude of the load current A battery system comprising a switching circuit that performs According to claim 1,
The switching circuit is
When the magnitude of the load current is equal to or smaller than the first threshold level, the first cell balancing operation is performed,
When the magnitude of the load current is greater than the first threshold level, the second cell balancing operation is performed. 3. The method of claim 2,
The first threshold level is,
The battery system, characterized in that determined based on a balancing current proportional to a difference between the state of charge of the first battery cell and the state of charge of the second battery cell. 4. The method of claim 3,
Further comprising a charging integrated circuit for charging the first battery cell or the second battery cell by outputting a charging current,
The charging integrated circuit comprises:
The battery system according to claim 1, wherein the charging current proportional to the balancing current is output during the first cell balancing operation. 5. The method of claim 4,
The switching circuit is
The battery system according to claim 1, wherein the first battery cell and the second battery cell are connected in series according to the presence or absence of the charging current. 5. The method of claim 4,
The charging integrated circuit comprises:
According to a result of comparison between the magnitude of the load current and a second threshold level greater than the first threshold level, the charging current having a magnitude determined based on the load current is output, or the charging current having a predetermined maximum magnitude Battery system, characterized in that output. According to claim 1,
The switching circuit is
The battery system according to claim 1, wherein the second cell balancing operation is performed until the state of charge of the first battery cell and the state of charge of the second battery cell are the same. first to third battery cells selectively connected to the first output terminal and the second output terminal, respectively;
a charging integrated circuit generating a charging current used for charging the first to third battery cells based on an external power source;
Cells for the first to third battery cells by connecting the first to third battery cells in series with each other according to the presence or absence of the charging current, and connecting at least one of the first to third battery cells to the first and second output terminals a switching circuit that performs a balancing operation; and
and a DC-DC converter connected to the first and second output terminals and including an input capacitor for providing a load current used as a power source of a load,
The charging integrated circuit comprises:
and generating the charging current having a magnitude determined based on the load current or a difference between the charging states of the first to third battery cells. 9. The method of claim 8,
The charging integrated circuit comprises:
When the magnitude of the load current is greater than a first threshold level and equal to or less than a second threshold level greater than the first threshold level, the charging current having a magnitude proportional to the load current is generated. system. 10. The method of claim 9,
The charging integrated circuit comprises:
When the magnitude of the load current is greater than the second threshold level, the battery system according to claim 1 , wherein the charging current having a predetermined maximum magnitude is output. 10. The method of claim 9,
The switching circuit is
When the magnitude of the load current is equal to or less than the first threshold level, a first battery cell having a relatively high state of charge among the first to third battery cells is connected to the input capacitor during a first period of a switching period, and , The cell balancing operation is performed by connecting a second battery cell having a relatively low state of charge among the first to third battery cells to the input capacitor during a second period of the switching period. 12. The method of claim 11,
The switching circuit is
When the magnitude of the load current is greater than the first threshold level, the first battery cell is connected to the input capacitor until the state of charge of the first battery cell is equal to that of the second battery cell. battery system. 12. The method of claim 11,
The first threshold level is,
The battery system, characterized in that determined based on the balancing current transferred from the first battery cell to the second battery cell during the switching period. 14. The method of claim 13,
The first threshold level is
A battery system, characterized in that it corresponds to twice the current level of the balancing current. 14. The method of claim 13,
The charging integrated circuit comprises:
When the magnitude of the load current is less than or equal to the first threshold level, the battery system, characterized in that generating the charging current proportional to the balancing current. simultaneously charging the plurality of battery cells by connecting the plurality of battery cells in series based on the presence or absence of a charging current provided to the plurality of battery cells; and
performing a first cell balancing operation or a second cell balancing operation based on the magnitude of a load current transferred from the plurality of battery cells to a system load,
During the first cell balancing operation, by transferring the voltage of a first battery cell having a relatively high state of charge among the plurality of battery cells to a second battery cell having a relatively low state of charge, the first battery cell and the second battery cell Cell balancing between battery cells is performed,
In the second cell balancing operation, by providing power to the system load using the first battery cell, cell balancing between the first battery cell and the second battery cell is performed. . 17. The method of claim 16,
The performing the first cell balancing operation or the second cell balancing operation comprises:
In response to the magnitude of the load current being less than or equal to a first threshold level, a charging current proportional to a balancing current generated based on a difference between a state of charge of the first battery cell and a state of charge of the second battery cell A method of operating an electronic device comprising the step of generating 18. The method of claim 17,
The first threshold level is,
Battery system, characterized in that twice the magnitude of the balancing current. 18. The method of claim 17,
The performing the first cell balancing operation or the second cell balancing operation comprises:
and generating a charging current proportional to the load current in response to the magnitude of the load current being greater than the first threshold level and less than the second threshold level. 20. The method of claim 19,
The performing the first cell balancing operation or the second cell balancing operation comprises:
and generating a charging current having a predetermined maximum magnitude in response to the magnitude of the load current being greater than the second threshold level.

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