Charging and discharging circuit and electronic equipment

Abstract

The invention discloses a charging and discharging circuit and electronic equipment. The charging and discharging circuit provided by the invention comprises a battery module, a charging integrated circuit module, a first switch module and a second switch module, the first end of the battery module is coupled with a first battery voltage detection pin of the charging integrated circuit module through a first path; the second end of the battery module is coupled with a second battery voltage detection pin of the charging integrated circuit module through a second path; the third end of the battery module is coupled with a third battery voltage detection pin of the charging integrated circuit module through a third path; wherein the first switch module is arranged on the second path, and the second switch module is arranged on the third path; the first switch module is used for enabling the second path to be in a disconnected state under the condition that the battery module is overcharged or overdischarged; and the second switch module is used for enabling the third path to be in a disconnected state under the condition that the battery module is overcharged or overdischarged.

Description

Technical Field

[0001] This application belongs to the field of electronic technology, specifically relating to a charging and discharging circuit and an electronic device. Background Technology

[0002] In related technologies, in order to balance the voltage of different cells in a battery module, a fuel gauge module is needed to detect the voltage of different cells and discharge them through a balancing resistor between the different cells to ensure that the full charge voltage of different cells is the same, thus achieving the voltage balancing function of different cells.

[0003] However, in related technologies, introducing an additional fuel gauge module inside the battery module would occupy space on the protection board and exacerbate heat generation. To avoid this issue, related technologies offer an integrated fuel gauge solution, integrating the fuel gauge module into the charging integrated circuit (IC) module on the motherboard of the electronic device. In this case, a leakage path exists between the charging IC module and the battery module, causing safety issues. Summary of the Invention

[0004] This application provides a charging and discharging circuit and electronic device to avoid safety problems caused by leakage paths.

[0005] In a first aspect, this application provides a charging and discharging circuit, including: a battery module, a charging integrated circuit module, a first switch module, and a second switch module; The first end of the battery module is coupled to the first battery voltage detection pin of the charging integrated circuit module through a first path; the second end of the battery module is coupled to the second battery voltage detection pin of the charging integrated circuit module through a second path; and the third end of the battery module is coupled to the third battery voltage detection pin of the charging integrated circuit module through a third path. The first switch module is located in the second path, and the second switch module is located in the third path. The first switch module is used to disconnect the second path in the event of overcharging or over-discharging of the battery module; the second switch module is used to disconnect the third path in the event of overcharging or over-discharging of the battery module.

[0006] Secondly, this application provides an electronic device including the charging and discharging circuit as described in the first aspect.

[0007] In the embodiments of this application, the charging and discharging circuit includes a battery module, a charging integrated circuit module, a first switch module, and a second switch module. A first terminal of the battery module is coupled to a first battery voltage detection pin of the charging integrated circuit module via a first path. A second terminal of the battery module is coupled to a second battery voltage detection pin of the charging integrated circuit module via a second path. A third terminal of the battery module is coupled to a third battery voltage detection pin of the charging integrated circuit module via a third path. The first switch module is disposed in the second path, and the second switch module is disposed in the third path. The first switch module is used to disconnect the second path in the event of overcharging or over-discharging of the battery module. The second switch module is used to disconnect the third path in the event of overcharging or over-discharging of the battery module. Thus, the embodiments of this application can utilize the first switch module to disconnect the second path in the event of overcharging or over-discharging of the battery module, and utilize the second switch module to disconnect the third path in the event of overcharging or over-discharging of the battery module, avoiding safety issues caused by leakage in the second and third paths. Attached Figure Description

[0008] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A schematic diagram illustrating the addition of a fuel gauge IC to a battery pack as provided in related technologies; Figure 2 A schematic diagram of a motherboard-side charging IC module integrating a fuel gauge module, as provided in related technologies; Figure 3 A schematic diagram of a charging and discharging circuit provided for some embodiments of this application; Figure 4 A schematic diagram of a charging and discharging circuit provided for some embodiments of this application; Figure 5 A schematic diagram of a charging and discharging circuit provided for some embodiments of this application; Figure 6 A schematic diagram of a charging and discharging circuit provided for some embodiments of this application; Figure 7 A schematic diagram of an electronic device provided for some embodiments of this application.

[0009] Explanation of reference numerals in the attached figures: 10-Charging / Discharging Circuit; 100-Battery Pack; 110-Battery Module; 111-First Cell; 112-Second Cell; 120-First Switch Module; 121-First Switching Element; M1-First Transistor; N1-First Inverter; 122-Second Switching Element; M2-Second Transistor; N2-Second Inverter; 130-Second Switch Module; 131-Third Switching Element; M3-Third Transistor; 132-Fourth Switching Element; M4-Fourth Transistor; 140-Protection Integrated Circuit Module; M5-Fifth Switching Element; M6-Sixth Switching Element; 200-Charging Integrated Circuit Module; 210-Equalization Module; 220-Fuel Meter Module L1 - First path; L2 - Second path; L3 - Third path; S1 - First battery voltage detection pin; S2 - Second battery voltage detection pin; S3 - Third battery voltage detection pin; S4 - Battery current detection pin; 1000 - Electronic device; VBATT2 - Power path pin; VBAT_SNS_P - Target detection pin; VBAT_SNS_M - First sub-voltage detection pin; PACK_SNS_M - Second sub-voltage detection pin; VBAT_2S_MID - Battery midpoint detection pin; IBAT_SNS_P - First sub-current detection pin; IBAT_SNS_M - Second sub-current detection pin; R BAL -Equalizing resistor; R sense - Sampling resistor; R1 - Cell internal resistance; CHG - First control pin; DSG - Second control pin; VC1 - First voltage pin; VC2 - Second voltage pin; VSS - Negative voltage pin; SRN - First current detection pin; SRP - Second current detection pin; VCELL1 - First power supply detection pin; VCELL2 - Second power supply detection pin. Detailed Implementation

[0010] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0011] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0012] In the description of this application, it should be understood that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0013] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0014] Currently, to improve mobile phone charging speed, many smart terminal products in the industry use a multi-cell series design for charging. This multi-cell series design provides higher charging power for electronic devices. The series connection increases the cell voltage by several times, resulting in a significantly higher charging voltage. Taking dual-cell series as an example, under the same charging power, the current in the charging path of the dual-cell design is only half that of the single-cell design. When the charging current is halved, the heat dissipation before and after the charging IC is reduced to 1 / 4 of that of the single-cell design. Using a dual-cell design can greatly improve charging heat dissipation, increasing both charging current and charging power under the same charging heat dissipation conditions, thus significantly improving the user's charging speed and charging experience. However, because two cells are used in series, the two batteries need to be balanced. Specifically, the charging voltage of different cells needs to be detected, and discharge is performed through a balancing resistor between the two cells to ensure that the full-charge voltage of both cells is the same, preventing one cell from fully charging while the other fails to do so.

[0015] Currently, for dual-cell series battery solutions, the relevant technologies can be implemented using dedicated fuel gauge ICs. For example... Figure 1 As shown, the external independent fuel gauge module mainly includes three functions: First, cell protection, which uses the DSG and CHG control pins to control two MOSFET switches to protect against overcharge and over-discharge currents, and the VC2 and VC1 pins to detect and protect against overcharge and over-discharge voltages of the cells. Second, it implements the battery fuel gauge function, using the SRN and SRP detection pins and the sampling resistor R... sense The charging and discharging current is detected, and the fuel meter function is implemented through algorithms such as coulomb integration. Thirdly, the equalization resistor R... BALThe battery level meter module enables the balancing function of the two battery cells.

[0016] Dual-cell series-connected battery packs using dedicated external fuel gauges, while effectively achieving battery power detection, battery balancing, and battery protection, require an independent fuel gauge module inside the battery pack. This internal module presents several significant drawbacks. First, the additional (external) fuel gauge IC occupies space on the protection board, increasing power trace impedance and exacerbating charging heat generation. Second, the additional fuel gauge and logic control ICs increase the risk of component failure due to inherent IC limitations. Furthermore, since the charging IC on the mainboard integrates both a fuel gauge and battery balancing module (which poses a leakage risk and impacts battery safety by default), using an external fuel gauge significantly increases overall material costs. To overcome these drawbacks, related technologies can utilize the charging IC on the mainboard, which integrates both a fuel gauge and battery balancing module to achieve battery power detection and balancing.

[0017] like Figure 2 As shown, the solution uses the integrated fuel gauge module within the charging IC on the motherboard to replace the fuel gauge function of an external fuel gauge IC, the integrated equalization module within the charging IC to replace the battery equalization function of the external fuel gauge IC, and a separate protection IC (significantly cheaper and smaller than an external fuel gauge IC) to replace the battery protection function of the fuel gauge. However, the solution of directly using the fuel gauge integrated within the charging IC also has leakage risks and defects affecting battery safety: First, the risk of battery overcharging due to continued charging after overcharge protection. Second, the risk of battery over-discharge due to continued discharging after over-discharge protection.

[0018] For example, in Figure 2 In the process, when the battery is overcharged, the battery pack's independent protection IC detects this and outputs a low level for CHG. This low CHG output disconnects the corresponding charging protection MOSFET, preventing further charging and potential safety issues caused by overcharging. However, compared to... Figure 1 Compared to the proposed solution, Figure 2The proposed solution introduces three additional potential leakage paths: ① a positive voltage detection path from the VBAT_SNS_P pin to the battery cell; ② a battery balancing connection path from the VBAT_2S_MID pin to the battery cell; and ③ a negative voltage detection path from the VBAT_SNS_M / PACK_SNS_M pin to the battery cell. These three newly added paths ①, ②, and ③ can continue charging after the protection IC disconnects the CHG charging path, potentially leading to overcharging. Specifically, the continued charging circuit for the first battery cell includes the power path pin VBATT2 from the motherboard charging IC, the first battery cell, and the balancing resistor R. BAL The closed loop formed by path ② and the VBAT_2S_MID pin. The continued charging circuit of the second cell 112 includes the VBAT_2S_MID pin of the charging IC on the motherboard (charging IC abnormal charging), path ②, and equalization resistor R. BAL The second battery cell 112, path ③, and the closed loop formed by the VBAT_SNS_M / PACK_SNS_M pins constitute the continued charging circuit for both cells. The continued charging circuit for the two cells includes a closed loop formed by the power path pin VBATT2 of the motherboard charging IC, the two cells, path ③, and the VBAT_SNS_M / PACK_SNS_M pins. Due to the existence of these three continued charging paths, directly using the motherboard charging IC's built-in fuel gauge solution carries the risk of battery overcharging after overcharge protection is activated, posing a battery safety issue.

[0019] For example, in Figure 2 In the process, when the battery is over-discharged, the battery pack's independent protection IC detects this and outputs a low level to the DSG. This low-level DSG output disconnects the corresponding discharge protection MOSFET, preventing further discharge to the motherboard and subsequent severe damage to the battery cells, such as battery bulging. As mentioned above, with... Figure 1 Compared to the proposed solution, Figure 2 The scheme shown also has three abnormal discharge paths: the discharge circuit of the first cell includes the positive terminal of the first cell, the power path pin VBATT2, the inside of the charging IC, the VBAT_2S_MID pin of the charging IC, path ②, and the equalization resistor R. BAL A closed loop is formed by the negative terminal of the first battery cell. The continued discharge circuit of the second battery cell 112 includes the positive terminal of the second battery cell 112 and the equalization resistor R. BALThe first three paths form a closed loop: path ②, the VBAT_2S_MID pin of the charging IC, the internal circuitry of the charging IC, the VBAT_SNS_M / PACK_SNS_M pins, and path ③ leading to the negative terminal of the second cell 112. The second path continues to discharge through the two cells, forming a closed loop consisting of the positive terminal of the first cell, the power path pin VBATT2, the internal circuitry of the charging IC, the VBAT_SNS_M / PACK_SNS_M pins, and path ③ leading to the negative terminal of the second cell 112. The existence of these three discharge loops poses a risk of battery over-discharge due to continued discharge after over-discharge protection, posing a battery safety concern.

[0020] Based on this, the charging and discharging circuit provided in this application embodiment adds a first switch module to the second path to disconnect the second path when the battery module is overcharged or over-discharged, and adds a second switch module to the third path to disconnect the third path when the battery module is overcharged or over-discharged, thereby avoiding safety issues caused by leakage of the battery module through the second and third paths and improving the safety of the battery module.

[0021] The following describes in detail, with reference to the accompanying drawings, a charging and discharging circuit and electronic device provided in the embodiments of this application.

[0022] like Figure 3 As shown, this application embodiment provides a charging and discharging circuit 10, which may include: Battery module 110, charging integrated circuit module 200, first switch module 120 and second switch module 130; The first end of the battery module 110 is coupled to the first battery voltage detection pin S1 of the charging integrated circuit module 200 through the first path L1; the second end of the battery module 110 is coupled to the second battery voltage detection pin S2 of the charging integrated circuit module 200 through the second path L2; and the third end of the battery module 110 is coupled to the third battery voltage detection pin S3 of the charging integrated circuit module 200 through the third path L3. The first switch module 120 is located in the second path L2, and the second switch module 130 is located in the third path L3. The first switch module 120 is used to disconnect the second path L2 in the event of overcharging or over-discharging of the battery module 110; the second switch module 130 is used to disconnect the third path L3 in the event of overcharging or over-discharging of the battery module 110.

[0023] In this embodiment, the battery module 110 may include multiple battery cells connected in series. The number of battery cells may be two, three, four, etc. Figure 3The use of only two battery cells as an example does not imply any limitation; this application does not impose any limitation on the specific number of battery cells.

[0024] In this embodiment, the first end of the battery module 110 can be the positive terminal of the battery module 110, and the first path L1 can be the positive terminal voltage detection path of the battery; the second end of the battery module 110 can be the connection point between two cells connected in series inside the battery module 110, and the second path L2 can be the midpoint voltage detection path of the battery; the third end of the battery module 110 can be the negative terminal of the battery module 110, and the third path L3 can be the negative terminal voltage detection path of the battery.

[0025] Overcharging of battery module 110 can refer to the voltage of battery module 110 being greater than a first voltage threshold. For example, when the voltage of battery module 110 is greater than 4.45V, battery module 110 is considered to be in an overcharged state. Over-discharging of battery module 110 can refer to the voltage of battery module 110 being less than a second voltage threshold. For example, when the voltage of battery module 110 is less than 2.1V, battery module 110 is considered to be in an over-discharged state.

[0026] In addition, overcharging of battery module 110 can also refer to the voltage of at least one cell in battery module 110 being greater than the third voltage threshold, in which case battery module 110 is considered overcharged; over-discharging of battery module 110 can also refer to the voltage of at least one cell in battery module 110 being less than the fourth voltage threshold, in which case battery module 110 is considered over-discharged.

[0027] In this embodiment, a combination of any two of the first path L1, the second path L2, and the third path L3 may constitute a closed loop that causes leakage in the battery module 110. For example, refer to... Figure 3 A closed loop formed by the first path L1, the first battery cell 111, the second path L2, and the charging integrated circuit module 200 may cause leakage in the first battery cell 111. Similarly, a closed loop formed by the second path L2, the second battery cell 112, the third path L3, and the charging integrated circuit module 200 may cause leakage in the second battery cell 112. Furthermore, a closed loop formed by the first path L1, two battery cells, the third path L3, and the charging integrated circuit module 200 may cause leakage in both battery cells. To address these leakage closed loops, a first switch module 120 is added to the second path L2, and a second switch module 130 is added to the third path L3. These newly added switch modules disconnect the leakage path in the event of overcharging or over-discharging of the battery module 110, thereby avoiding the risk of leakage and improving the safety of the battery module 110.

[0028] Thus, according to the charging and discharging circuit 10 provided in the embodiments of this application, the embodiments of this application can use the first switch module 120 to disconnect the second path L2 in the case of overcharging or over-discharging of the battery module 110, and use the second switch module 130 to disconnect the third path L3 in the case of overcharging or over-discharging of the battery module 110, so as to avoid overcharging or over-discharging problems caused by leakage of the battery cell 111 in the battery module 110 through the second path L2 and the third path L3, thereby improving the safety of the battery module 110.

[0029] In practical applications, at least two series-connected switching elements can be set in switching modules such as the first switching module 120 and the second switching module 130. These two switching elements can then cut off the leakage path in overcharge and over-discharge scenarios, respectively, avoiding leakage risks and improving the safety of the battery module 110. An example is given below.

[0030] In a specific embodiment, for the first switch module 120, as follows: Figure 4 As shown, the first switch module 120 may include a first switch element 121 and a second switch element 122 connected in series; the first switch element 121 is in the off state when the battery module 110 is overcharged; the second switch element 122 is in the off state when the battery module 110 is over-discharged.

[0031] The first switching element 121 can be regarded as a control switch to disconnect the continuing charging circuit, and the second switching element 122 can be regarded as a control switch to disconnect the continuing discharging circuit.

[0032] It can be understood that one end of the first switching element 121 is connected to the second switching element 122, and the other end is connected to the second terminal of the battery module 110; one end of the second switching element 122 is connected to the first switching element 121, and the other end is connected to the second battery voltage detection pin S2 of the charging integrated circuit module 200; or, one end of the first switching element 121 is connected to the second switching element 122, and the other end is connected to the second battery voltage detection pin S2; one end of the second switching element 122 is connected to the first switching element 121, and the other end is connected to the second terminal of the battery module 110.

[0033] Similarly, one end of the third switch element 132 is connected to the fourth switch element 131, and the other end is connected to the third terminal of the battery module 110; one end of the fourth switch element 131 is connected to the third switch element 132, and the other end is connected to the third battery voltage detection pin S3 of the charging integrated circuit module 200; or, one end of the third switch element 132 is connected to the fourth switch element 131, and the other end is connected to the third battery voltage detection pin S3 of the charging integrated circuit module; one end of the fourth switch element 131 is connected to the third switch element 132, and the other end is connected to the third terminal of the battery module 110.

[0034] In this way, the overcharge protection and over-discharge protection functions are performed by two independent, series-connected switching elements. The first switching element 121 is dedicated to the charging circuit, and the second switching element 122 is dedicated to the discharging circuit. Even if one of the switches fails for some reason, the other switch can still act as a safety barrier to effectively prevent the battery module 110 from leaking current through the second path L2.

[0035] For example, such as Figure 5 or Figure 6 As shown, the first switching element 121 may include a first transistor M1, and the second switching element 122 may include a second transistor M2; In the event of overcharging of battery module 110, the first transistor M1 is in the off state; When the battery module 110 is over-discharged, the second transistor M2 is in the off state.

[0036] The first transistor M1 and the second transistor M2 can be either NMOS or PMOS transistors. This application does not limit the specific types of the first transistor M1 and the second transistor M2.

[0037] The first switching element 121 may also be composed of other types of switching components or combinations of switches, and the second switching element 122 may also be composed of other types of switching components or combinations of switches. This application does not impose specific limitations on the specific structure of the first switching element 121 and the second switching element 122.

[0038] For example, in other embodiments, such as Figure 6 As shown, the first switching element 121 may further include a first inverter N1, and the second switching element 122 may further include a second inverter N2. The control terminal of the first transistor M1 is coupled to the protection integrated circuit module 140 through the first inverter N1. The control terminal of the second transistor M2 is coupled to the protection integrated circuit module 140 through the second inverter N2. The first inverter N1 and the second inverter N2 are controlled by the protection integrated circuit module 140, which can realize the control and drive of the first transistor M1 and the second transistor M2, thereby improving the accuracy of the control and drive of the first transistor M1 and the second transistor M2.

[0039] In this way, the first transistor M1 is dedicated to protecting the charging circuit, and the second transistor M2 is dedicated to protecting the discharging circuit. Even if one of the transistors fails for some reason, the other transistor can still act as a safety barrier to effectively prevent the battery module 110 from leaking current through the second path L2.

[0040] Furthermore, the first transistor M1 and the second transistor M2 can be two back-to-back MOS transistors. In other words, the conduction directions of the body diode inside the first transistor M1 and the body diode inside the second transistor M2 are opposite.

[0041] For example, the charging current needs to flow against the conduction direction of the body diode inside the first transistor M1. Under normal charging conditions, the first transistor M1 is turned on, and the current flows through the low-resistance channel, bypassing its body diode. When overcharging occurs, the first transistor M1 is turned off. At this time, the channel of the first transistor M1 is open. The only path for the charging current to form a circuit is to try to flow "forward" through the body diode of the first transistor M1. However, at this time, the body diode of the first transistor M1 is in the off state, the charging circuit is completely cut off, the current cannot form a charging circuit, and charging stops.

[0042] Similarly, the discharge current needs to flow against the conduction direction of the body diode inside the second transistor M2. Under normal discharge conditions, the second transistor M2 is turned on, and the current flows through the low-resistance channel, bypassing its body diode. When over-discharge occurs, the second transistor M2 is turned off. At this time, the channel of the second transistor M2 is open. The only path for the discharge current to form a circuit is to try to flow "forward" through the body diode of the second transistor M2. However, at this time, the body diode of the second transistor M2 is in the off state, the discharge circuit is completely cut off, the current cannot form a discharge circuit, and the discharge stops.

[0043] In this way, by using two back-to-back series-connected MOSFETs M1 and M2, the leakage path is cut off in overcharge and over-discharge scenarios, respectively, avoiding the risk of leakage of the battery module 110 through the second path L2 and improving the safety of the battery module 110.

[0044] In a specific embodiment, for the second switch module 130, as follows: Figure 4 As shown, the second switch module 130 may include a third switch element 131 and a fourth switch element 132 connected in series; The third switching element 131 is in the off state when the battery module 110 is overcharged; the fourth switching element 132 is in the off state when the battery module 110 is over-discharged.

[0045] Among them, the third switching element 131 can be regarded as a control switch to disconnect the continuing charging circuit, and the fourth switching element 132 can be regarded as a control switch to disconnect the continuing discharging circuit.

[0046] In this way, the overcharge protection and over-discharge protection functions are performed by two independent, series-connected switching elements. The third switching element 131 is dedicated to the charging circuit, and the fourth switching element 132 is dedicated to the discharging circuit. Even if one of the switches fails for some reason, the other switch can still act as a safety barrier to effectively prevent the battery module 110 from leaking current through the third path L3.

[0047] For example, such as Figure 5 or Figure 6 As shown, the third switching element 131 includes a third transistor M3, and the fourth switching element 132 includes a fourth transistor M4; In the event of overcharging of battery module 110, the third transistor M3 is in the off state; In the event of over-discharge of battery module 110, the fourth transistor M4 is in the off state.

[0048] The third transistor M3 and the fourth transistor M4 can be either NMOS or PMOS transistors. This application does not limit the specific types of the third transistor M3 and the fourth transistor M4.

[0049] The third switching element 131 can also be composed of other types of switching components or combinations of switches, and the fourth switching element 132 can also be composed of other types of switching components or combinations of switches. This application does not impose specific limitations on the specific structure of the third switching element 131 and the fourth switching element 132.

[0050] In this way, the third transistor M3 is dedicated to protecting the charging circuit, and the fourth transistor M4 is dedicated to protecting the discharging circuit. Even if one of the MOSFETs fails for some reason, the other MOSFET can still serve as a safety barrier, effectively preventing the battery module 110 from leaking current through the third path L3.

[0051] Furthermore, the third transistor M3 and the fourth transistor M4 are two back-to-back MOSFETs. In other words, the conduction directions of the body diodes inside the third transistor M3 and the fourth transistor M4 are opposite.

[0052] For example, the charging current needs to flow against the conduction direction of the body diode inside the third transistor M3. Under normal charging conditions, the third transistor M3 is turned on, and the current flows through the low-resistance channel, bypassing its body diode. When overcharging occurs, the third transistor M3 is turned off. At this time, the channel of the third transistor M3 is open. The only path for the charging current to form a circuit is to try to flow "forward" through the body diode of the third transistor M3. However, at this time, the body diode of the third transistor M3 is in the off state, the charging circuit is completely cut off, the current cannot form a charging circuit, and charging stops.

[0053] Similarly, the discharge current needs to flow against the conduction direction of the body diode inside the fourth transistor M4. Under normal discharge conditions, the fourth transistor M4 is turned on, and the current flows through the low-resistance channel, bypassing its body diode. When over-discharge occurs, the fourth transistor M4 is turned off. At this time, the channel of the fourth transistor M4 is open. The only path for the discharge current to form a circuit is to try to flow "forward" through the body diode of the fourth transistor M4. However, at this time, the body diode of the fourth transistor M4 is in the off state, the discharge circuit is completely cut off, the current cannot form a discharge circuit, and the discharge stops.

[0054] In this way, by using two back-to-back series-connected MOSFETs M3 and M4, the third path L3 is cut off in overcharge and over-discharge scenarios, respectively, to avoid the risk of leakage of the battery module 110 through the third path L3 and improve the safety of the battery module 110.

[0055] In practical applications, such as Figure 4 , Figure 5 or Figure 6 As shown, the charging and discharging circuit 10 also includes a protection integrated circuit module 140. The control terminals of the first switching element 121 and the second switching element 122 are respectively connected to the protection integrated circuit module 140; the control terminals of the third switching element 131 and the fourth switching element 132 are respectively connected to the protection integrated circuit module 140.

[0056] For example, such as Figure 5 or Figure 6 As shown, taking the first switching element 121 including the first transistor M1, the second switching element 122 including the second transistor M2, the third switching element 131 including the third transistor M3, and the fourth switching element 132 including the fourth transistor M4 as an example, the first transistor M1, the second transistor M2, the third transistor M3, and the fourth transistor M4 can all be controlled by the protection integrated circuit module 140. The control terminals of the first transistor M1, the second transistor M2, the third transistor M3, and the fourth transistor M4 are all connected to the protection integrated circuit module 140.

[0057] In this way, the protection integrated circuit module 140 can output an overcharge protection signal to the control terminal of the first transistor M1 to control the first transistor M1 to disconnect, and output an over-discharge protection signal to the control terminal of the second transistor M2 to control the second transistor M2 to disconnect.

[0058] Similarly, as overcharge protection control switches, the control terminals of the first transistor M1 and the third transistor M3 can be connected to the same control source of the protection integrated circuit module 140. Likewise, as over-discharge protection control switches, the control terminals of the second transistor M2 and the fourth transistor M4 can be connected to the same control source of the protection integrated circuit module 140.

[0059] For example, the control terminals of the first switching element 121 and the third switching element 131 are respectively connected to the first control pin CHG of the protection integrated circuit module 140; the control terminals of the second switching element 122 and the fourth switching element 132 are respectively connected to the second control pin DSG of the protection integrated circuit module 140.

[0060] Taking the first switching element 121 including the first transistor M1, the second switching element 122 including the second transistor M2, the third switching element 131 including the third transistor M3, and the fourth switching element 132 including the fourth transistor M4 as an example, the first control pin CHG of the protection integrated circuit module 140 can output an overcharge protection signal to the control terminals of the first transistor M1 and the third transistor M3 to control the first transistor M1 and the third transistor M3 to disconnect. In addition, the second control pin DSG of the protection integrated circuit module 140 outputs an over-discharge protection signal to the control terminals of the second transistor M2 and the fourth transistor M4 to control the second transistor M2 and the fourth transistor M4 to disconnect.

[0061] In practical applications, such as Figure 3 As shown, the first end of the battery module 110 is also coupled to the power path pin VBATT2 of the charging integrated circuit module 200. The first end of the battery module 110 can be the positive terminal of the battery module 110, and the path between the battery module 110 and the power path pin VBATT2 of the charging integrated circuit module 200 can be used for charging and discharging the battery module 110.

[0062] Taking a battery module consisting of two cells as an example, such as Figure 3 As shown, the battery module 110 includes a first cell 111 and a second cell 112 connected in series; the first end of the battery module 110 includes the first end of the first cell; the second end of the battery module 110 includes the second end of the first cell 111 and the first end of the second cell 112; the third end of the battery module 110 includes the second end of the second cell 112. The first end of the first cell 111 is connected to the first path L1, and the second end of the first cell 111 is connected to the second path L2; the first end of the second cell 112 is connected to the second path L2, and the second end of the second cell 112 is connected to the third path L3.

[0063] In this configuration, the first end of the battery module 110 is the positive electrode, the second end of the battery module 110 is the cell connection point, and the third end of the battery module 110 is the negative electrode. The first end of the first cell 111 is the positive electrode, the second end of the first cell 111 is the negative electrode, the first end of the second cell 112 is the positive electrode, and the second end of the second cell 112 is the negative electrode.

[0064] Wherein, the first path L1 can be the positive voltage detection path of the first cell 111, the second path L2 can be the voltage detection path at the midpoint between the first cell 111 and the second cell 112, and the third path L3 can be the negative voltage detection path of the second cell 112.

[0065] In this way, a first switch module 120 is added to the second path L2 and a second switch module 130 is added to the third path L3. The newly added switch modules can disconnect the leakage path in the event of overcharging or over-discharging of the first cell 111 and the second cell 112, thereby avoiding the risk of leakage and improving the safety of the first cell 111 and the second cell 112.

[0066] In practical applications, such as Figure 6 As shown, the charging and discharging circuit 10 includes a protection integrated circuit module 140. The first end of the first battery cell 111 is connected to the first power detection pin VCELL1 of the protection integrated circuit module 140, and the second end of the first battery cell 111 (the first end of the second battery cell 112) is connected to the second power detection pin VCELL2 of the protection integrated circuit module. The protection integrated circuit module 140 can detect and determine the power supply voltage of the first battery cell 111 and the power supply voltage of the second battery cell 112 through the first power detection pin VCELL1 and the second power detection pin VCELL2, thereby realizing overcharge protection and over-discharge protection functions.

[0067] like Figure 6 As shown, the charging and discharging circuit 10 may further include a fifth switching element M5 and a sixth switching element M6 connected in series. The control terminals of the fifth switching element M5 and the sixth switching element M6 are both connected to the protection integrated circuit module 140. The protection integrated circuit module 140 can be coupled to the third terminal of the battery module 110 through the fifth switching element M5, and the protection integrated circuit module 140 can be coupled to the battery current detection pin S4 of the charging integrated circuit module 200 through the sixth switching element M6.

[0068] Among them, the power path pin VBATT2 of the charging integrated circuit module 200, the battery module 110, the fifth switching element M5, the sixth switching element M6, and the sampling resistor R are all connected. senseThe resulting closed loop is the charging and discharging circuit of battery module 110. Among them, the sampling resistor R... sense One end is connected to the sixth switching element M6, and the other end is grounded.

[0069] Among them, the fifth switching element M5 can be an over-discharge protection switch; the sixth switching element M6 can be an overcharge protection switch, thereby realizing the charging and discharging protection function.

[0070] For example, the protection integrated circuit module 140 detects through the first power detection pin VCELL1 and the second power detection pin VCELL2 that the power supply voltage of the first cell 111 or the power supply voltage of the second cell 112 is greater than a third voltage threshold, and determines that the battery module is overcharged. Therefore, it can output an overcharge protection signal through the first control pin CHG to the control terminals of the first transistor M1, the third transistor M3, and the sixth switching element M6 to control the first transistor M1, the third transistor M3, and the sixth switching element M6 to disconnect. By disconnecting the sixth switching element M6, the overcharge protection function is achieved.

[0071] For example, the protection integrated circuit module 140 detects through the first power detection pin VCELL1 and the second power detection pin VCELL2 that the power supply voltage of the first cell 111 or the power supply voltage of the second cell 112 is less than the fourth voltage threshold, and determines that the battery module is in an over-discharge state. Therefore, it can output an over-discharge protection signal through the second control pin DSG to the control terminals of the second transistor M2, the fourth transistor M4, and the five-switch element M5 to control the second transistor M2, the fourth transistor M4, and the five-switch element M5 to disconnect. By disconnecting the five-switch element M5, the over-discharge protection function is achieved.

[0072] The battery current detection pin S4 of the charging integrated circuit module 200 includes: a first sub-current detection pin IBAT_SNS_P and a second sub-current detection pin IBAT_SNS_M, and a sampling resistor R. sense The two ends of the device are connected to the fuel gauge module 220 integrated inside the charging integrated circuit module 200 via the first sub-current detection pin IBAT_SNS_P and the second sub-current detection pin IBAT_SNS_M, thereby realizing the fuel gauge function. Sampling resistor R sense The two ends are connected to the first sub-current detection pin IBAT_SNS_P and the second sub-current detection pin IBAT_SNS_M, respectively.

[0073] For example, the fuel gauge module 220 uses the first sub-current detection pin IBAT_SNS_P and the second sub-current detection pin IBAT_SNS_M to sample the resistor R. senseThe charging or discharging current at both ends is detected, and then the charging or discharging current is integrated and calculated using algorithms such as coulomb integration to obtain the battery module 110's charge level, thus realizing the function of a fuel gauge.

[0074] In this way, the equalization module 210 and the fuel gauge module 220 integrated inside the charging integrated circuit module 200 replace the additional fuel gauge integrated circuit in the battery pack 100, saving layout space of the battery pack protection board, increasing the width of the power trace, reducing the trace impedance, reducing charging heat generation, and improving the charging experience.

[0075] Among them, the second battery voltage detection pin S2 includes the battery midpoint detection pin VBAT_2S_MID, such as Figure 6 As shown, a balancing resistor R is also installed on the second path L2. BAL Equalizing resistor R BAL The equalization module 210 integrated within the charging integrated circuit module 200 is connected to the battery midpoint detection pin VBAT_2S_MID. The equalization module 210 can be connected via the equalization resistor R. BAL Discharge, thereby achieving voltage balance between the first cell 111 and the second cell 112.

[0076] The charging and discharging circuit 10 may also include a battery pack 100, a battery module 110 and a protection integrated circuit module 140 which may be located within the battery pack 100. The protection integrated circuit module 140 may be an existing integrated circuit module in the battery pack 100, and the charging integrated circuit module 200 may be an integrated circuit module with an integrated fuel meter function.

[0077] In this way, the cost and area occupied by the protection integrated circuit module 140 are much smaller than those of an additional fuel gauge integrated circuit, which can avoid the use of an additional fuel gauge integrated circuit in the battery pack 100 and reduce device failure.

[0078] The following is based on Figure 6 Taking this as an example, the charging and discharging process of the charging and discharging circuit is described in detail. The first battery voltage detection pin S1 includes the target detection pin VBAT_SNS_P, the second battery voltage detection pin S2 includes the battery midpoint detection pin VBAT_2S_MID, and the third battery voltage detection pin S3 includes the first sub-voltage detection pin VBAT_SNS_M and the second sub-voltage detection pin PACK_SNS_M.

[0079] The first scenario involves the charging / discharging circuit charging normally: Battery module 110 did not experience overcharge / over-discharge. Protection integrated circuit module 140 controlled all six MOSFETs M1-M6 to be turned on. The charging current path of battery module 110 includes the first cell 111, the second cell 112, MOSFET M5, MOSFET M6, and sampling resistor R via power path pin VBATT2. sense A closed loop formed to the reference point.

[0080] Other signals also function normally. The charging integrated circuit module 200 detects the voltage of the two cells through the target detection pin VBAT_SNS_P, the first sub-voltage detection pin VBAT_SNS_M, and the second sub-voltage detection pin PACK_SNS_M. The charging integrated circuit module 200 detects the voltage of the two cells through the first sub-current detection pin IBAT_SNS_P, the second sub-current detection pin IBAT_SNS_N, and the sampling resistor R. sense Current sampling is performed for power calculation. The charging integrated circuit module 200 detects the voltage of the two cells through the target detection pin VBAT_SNS_P, the battery midpoint detection pin VBAT_2S_MID, and the first sub-voltage detection pin VBAT_SNS_M. When an abnormality is detected, the voltage is adjusted through the equalization resistor R. BAL Discharge to balance the voltage of the first cell 111 and the second cell 112.

[0081] The second scenario involves overcharging in the charging / discharging circuit: When the battery module 110 is overcharged, the protection integrated circuit module 140 controls the three MOSFETs M1, M3, and M6 used for charging protection to disconnect.

[0082] The continued charging circuit of the first battery cell 111 includes a power path pin VBATT2, the first battery cell, MOSFET M2, MOSFET M1, and equalization resistor R. BAL The closed loop formed by the battery midpoint detection pin VBAT_2S_MID and the reference ground disconnects the continuing charging circuit of the first cell 111 when the MOSFET M1 is turned off, thus preventing the first cell 111 from being overcharged.

[0083] The continued charging circuit of the second cell 112 includes a battery midpoint detection pin VBAT_2S_MID and an equalization resistor R. BAL The closed loop formed by MOSFET M1, MOSFET M2, second cell 112, MOSFET M4, MOSFET M3, first sub-voltage detection pin VBAT_SNS_M, second sub-voltage detection pin PACK_SNS_M to reference ground disconnects the continued charging circuit of second cell 112 when MOSFET M1 and MOSFET M3 are disconnected, thus preventing overcharging of second cell 112.

[0084] The continued charging circuit of the first battery cell 111 and the second battery cell 112 includes a closed loop consisting of the power path pin VBATT2, the first battery cell 111, the second battery cell 112, MOSFET M4, MOSFET M3, the first sub-voltage detection pin VBAT_SNS_M, the second sub-voltage detection pin PACK_SNS_M, and the reference ground. When MOSFET M3 is turned off, the continued charging circuit of the second battery cell 112 is disconnected to prevent the second battery cell 112 from being overcharged.

[0085] The conventional charging circuit of battery module 110 includes a power path pin VBATT2, a first cell 111, a second cell 112, MOSFET M5, MOSFET M6, and a sampling resistor R. sense The closed loop formed by the IBAT_SNS_P and IBAT_SNS_N pins disconnects the normal charging circuit when the MOSFET M6 is turned off, thus preventing the battery module 110 from being overcharged.

[0086] The third scenario involves over-discharge in the charging / discharging circuit: When the battery module 110 is over-discharged, the protection integrated circuit module 140 controls the three MOSFETs M2, M4, and M5 used for discharge protection to disconnect.

[0087] The continued discharge circuit of the first cell 111 includes the positive terminal of the first cell, the power path pin VBATT2, the battery midpoint detection pin VBAT_2S_MID, and the equalization resistor R. BAL The closed loop formed by MOSFETs M1 and M2 to the negative terminal of the first battery cell disconnects the continued discharge circuit of the first battery cell 111 when MOSFET M2 is turned off, thus preventing the first battery cell 111 from being over-discharged.

[0088] The continued discharge circuit of the second cell 112 includes the positive terminal of the second cell 112, MOSFET M2, MOSFET M1, and equalization resistor R. BAL The closed loop formed by the battery midpoint detection pin VBAT_2S_MID, the first sub-voltage detection pin VBAT_SNS_M, the second sub-voltage detection pin PACK_SNS_M, MOSFET M3, MOSFET M4 and the negative terminal of the second cell 112, when MOSFET M2 and MOSFET M4 are disconnected, the continued discharge circuit of the second cell 112 is disconnected, thus preventing the second cell 112 from being over-discharged.

[0089] The continued discharge circuit of the first battery cell 111 and the second battery cell 112 includes a closed loop consisting of the positive terminal of the first battery cell, the power path pin VBATT2, the inside of the charging integrated circuit, the first sub-voltage detection pin VBAT_SNS_M, the second sub-voltage detection pin PACK_SNS_M, MOSFET M3, MOSFET M4 to the negative terminal of the second battery cell 112. When MOSFET M4 is turned off, the continued discharge circuit of the first battery cell 111 and the second battery cell 112 is disconnected, thus preventing the first battery cell 111 and the second battery cell 112 from being over-discharged.

[0090] The conventional discharge circuit of the battery module 110 includes the positive terminal of the first battery cell, the power path pin VBATT2, the interior of the charging integrated circuit module 200, the reference ground of the charging integrated circuit module 200, and the sampling resistor R. sense The closed loop formed by MOSFETs M6 and M5 to the negative terminal of the second cell 112 disconnects the normal discharge circuit of the battery module 110 when MOSFET M5 is disconnected, thus avoiding the risk of battery bulging due to over-discharge of the battery module 110.

[0091] In this way, by adding MOSFETs M1 and M2 in the second path L2, the second path L2 is disconnected by MOSFETs M1 and M2 in the case of overcharging or over-discharging of the battery module 110. And by adding MOSFETs M3 and M4 in the third path L3, the third path L3 is disconnected by MOSFETs M3 and M4 in the case of overcharging or over-discharging of the battery module 110. This avoids the overcharging or over-discharging problem caused by leakage of the cells in the battery module 110 through the second path L2 and the third path L3, thereby improving the safety of the battery module 110.

[0092] Based on the same concept as the charging and discharging circuits provided in any of the above embodiments, this application also provides an electronic device.

[0093] like Figure 7 As shown in the figure, this application provides an electronic device 1000, including a charging and discharging circuit 10.

[0094] It should be noted that the electronic device provided in this application includes the charging and discharging circuit provided in any of the above embodiments, and can realize all the functions of the charging and discharging circuit. To avoid repetition, it will not be described again here.

[0095] In the embodiments of this application, the electronic device can be a terminal or a device other than a terminal. For example, the electronic device can be a smartwatch, mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), etc. The embodiments of this application do not specifically limit the scope.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A charge-discharge circuit characterized by comprising: The battery module, the charging integrated circuit module, the first switch module and the second switch module are included. The first end of the battery module is coupled with the first battery voltage detection pin of the charging integrated circuit module through a first path; the second end of the battery module is coupled with the second battery voltage detection pin of the charging integrated circuit module through a second path; and the third end of the battery module is coupled with the third battery voltage detection pin of the charging integrated circuit module through a third path. The first switch module is arranged in the second path, and the second switch module is arranged in the third path. The first switch module is used to make the second path in an open state in the case of overcharge or overdischarge of the battery module; and the second switch module is used to make the third path in an open state in the case of overcharge or overdischarge of the battery module. The first switch module includes a first switch element and a second switch element connected in series; the first switch element is in an open state in the case of overcharge of the battery module; and the second switch element is in an open state in the case of overdischarge of the battery module.

2. The charge and discharge circuit according to claim 1, characterized by, The second switch module includes a third switch element and a fourth switch element connected in series; the third switch element is in an open state in the case of overcharge of the battery module; and the fourth switch element is in an open state in the case of overdischarge of the battery module. The first switch element includes a first transistor, and the second switch element includes a second transistor; the first transistor is in an open state in the case of overcharge of the battery module; and the second transistor is in an open state in the case of overdischarge of the battery module.

3. The charge and discharge circuit according to claim 2, wherein The third switch element includes a third transistor, and the fourth switch element includes a fourth transistor; the third transistor is in an open state in the case of overcharge of the battery module; and the fourth transistor is in an open state in the case of overdischarge of the battery module. The charging and discharging circuit further includes a protection integrated circuit module; the control end of the first switch element and the control end of the second switch element are respectively connected with the protection integrated circuit module; and the control end of the third switch element and the control end of the fourth switch element are respectively connected with the protection integrated circuit module.

4. The charge and discharge circuit according to claim 2, wherein The control end of the first switch element and the control end of the third switch element are respectively connected with the first control pin of the protection integrated circuit module; and the control end of the second switch element and the control end of the fourth switch element are respectively connected with the second control pin of the protection integrated circuit module.

5. The charge and discharge circuit according to claim 4, wherein The first end of the battery module is further coupled with the power path pin of the charging integrated circuit module.

6. The charge and discharge circuit according to claim 1, wherein The battery module includes a first battery cell and a second battery cell connected in series; the first end of the battery module includes the first end of the first battery cell; the second end of the battery module includes the second end of the first battery cell and the first end of the second battery cell; and the third end of the battery module includes the second end of the second battery cell.

7. The charge and discharge circuit according to any one of claims 1 to 6, wherein ​ The first end of the first battery cell is connected with the first path, and the second end of the first battery cell is connected with the second path; the first end of the second battery cell is connected with the second path, and the second end of the second battery cell is connected with the third path.

8. The charge and discharge circuit according to claim 7, wherein The charging and discharging circuit comprises a protection integrated circuit module, the first end of the first battery cell is connected with a first power supply detection pin of the protection integrated circuit module, and the second end of the first battery cell is connected with a second power supply detection pin of the protection integrated circuit module.

9. The charge and discharge circuit according to claim 3, wherein The first switch element further comprises a first inverter, and the second switch element further comprises a second inverter; The control end of the first transistor is coupled with the protection integrated circuit module through the first inverter; The control end of the second transistor is coupled with the protection integrated circuit module through the second inverter.

10. The charge and discharge circuit according to claim 4, wherein The charging and discharging circuit further comprises a fifth switch element and a sixth switch element connected in series; the control end of the fifth switch element and the control end of the sixth switch element are both connected with the protection integrated circuit module; the protection integrated circuit module is coupled with the third end of the battery module through the fifth switch element, and the protection integrated circuit module is coupled with the battery current detection pin of the charging integrated circuit module through the sixth switch element.

11. An electronic device, comprising: The charging and discharging circuit comprises the charging and discharging circuit according to any one of claims 1-10.

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