A battery charging protection circuit

Abstract

The application provides a battery charging protection circuit, comprising: a first end of a protection integrated circuit element is connected with a battery through a battery interface; a second end of the protection integrated circuit element is connected with a charging power supply through a power supply interface; a first circuit control element and a second circuit control element are arranged in parallel between the second end of the protection integrated circuit element and the power supply interface; the first circuit control element and the second circuit control element are turned on or turned off through a control signal of the protection integrated circuit element; if the first circuit control element is in a non-working state, the second circuit control element is turned on or turned off through the control signal of the protection integrated circuit element, so as to protect the battery. The first circuit control element and the second circuit control element are arranged in parallel between the protection integrated circuit element and the power supply interface, and the double-circuit control elements of the battery are controlled through one protection integrated circuit element, so that the battery is protected.

Description

Technical Field

[0001] This application relates to the field of battery charging, specifically to a battery charging protection circuit. Background Technology

[0002] Currently, with the rapid development of portable electronic devices, battery charging technologies have been applied to portable electronic devices, and charging portable electronic devices has received widespread attention. At the same time, the performance requirements for battery charging are becoming increasingly stringent.

[0003] Even after the battery is fully charged, the thermistor's resistance may still send an incorrect feedback signal to the system, indicating that the battery can still be charged. This causes the power interface to continue charging the battery, creating a safety hazard. Furthermore, the characteristics of lithium-ion batteries—their inability to be overcharged or over-discharged—need to be addressed with a protection circuit board. However, the operation of this protection circuit board also consumes battery power. During long-term storage or transportation, this power consumption can accelerate the risk of over-discharge. Based on the above analysis, it is necessary to address the protection issues during the battery's charging and discharging processes to prevent overcharging and over-discharging.

[0004] Therefore, how to protect the battery during charging and discharging is a problem that needs to be solved. Utility Model Content

[0005] This application provides a battery charging protection circuit to protect the battery during the charging and discharging processes.

[0006] This application provides a battery charging protection circuit, including: a protection integrated circuit element, a battery interface, a power interface, a first circuit control element, and a second circuit control element; a first terminal of the protection integrated circuit element is connected to a battery through the battery interface; a second terminal of the protection integrated circuit element is connected to a charging power source through the power interface; the first circuit control element and the second circuit control element are connected in parallel between the second terminal of the protection integrated circuit element and the power interface; both the first circuit control element and the second circuit control element are turned on or off by a control signal from the protection integrated circuit element; the first terminal and the second terminal are pin interfaces in the protection integrated circuit element for connecting with other components; if the first circuit control element is in a non-operating state, the second circuit control element is turned on or off by the control signal from the protection integrated circuit element to protect the battery.

[0007] Compared with the prior art, this application has the following advantages:

[0008] This application provides a battery charging protection circuit, including: a protection integrated circuit element, a battery interface, a power interface, a first circuit control element, and a second circuit control element. A first terminal of the protection integrated circuit element is connected to a battery through the battery interface; a second terminal of the protection integrated circuit element is connected to a charging power source through the power interface. The first circuit control element and the second circuit control element are connected in parallel between the second terminal of the protection integrated circuit element and the power interface. Both the first and second circuit control elements are turned on or off by a control signal from the protection integrated circuit element. The first and second terminals are pin interfaces in the protection integrated circuit element used for connecting to other components. If the first circuit control element is in a non-operating state, the control signal from the protection integrated circuit element controls the on / off state of the second circuit control element to protect the battery. This application protects the battery by connecting the first and second circuit control elements in parallel between the protection integrated circuit element and the power interface, using a dual circuit control element controlled by a single protection integrated circuit element. Attached Figure Description

[0009] Figure 1 This is a battery charging circuit diagram in the related technology of the embodiments of this application.

[0010] Figure 2 This is a circuit diagram of the battery charging protection circuit proposed in the embodiments of this application.

[0011] Figure label:

[0012] Figure 2 Figure labels in the diagram:

[0013] 101: Protects integrated circuit components; 102: First MOSFET; 103: Second MOSFET; 104: Diode; 105: Ninth capacitor; 106: Eighth capacitor; 107: Fifth resistor;

[0014] 200: First on / off control circuit module; 201: Third MOSFET; 201-1: Second resistor; 201-2: Fourth capacitor;

[0015] 202: Fourth MOSFET; 202-1: Third resistor; 202-2: Fifth capacitor;

[0016] 300: Thermistor module; 301: Negative temperature coefficient thermistor (NTC); 302: Fifth MOSFET; 303: Sixth capacitor; 304: Seventh capacitor; 305: Resistance box;

[0017] 400: First voltage divider protection module; 401: First resistor; 402: First capacitor;

[0018] 500: Second voltage divider protection module; 501: Second capacitor; 502: Third capacitor;

[0019] 600: Fourth resistor; 700: Sixth resistor.

[0020] Figure 1 Figure labels in the diagram:

[0021] 10: First semiconductor module; 10-1: Sixth MOSFET; 10-2: Seventh MOSFET;

[0022] 20: Seventh resistor; 30: Tenth capacitor; 40: Eleventh capacitor; 50: Twelfth capacitor;

[0023] 60: Eighth resistor; 70: Thirteenth capacitor; 80: Second semiconductor module; 80-1: Eighth MOSFET; 80-2: Ninth MOSFET; 90: Fourteenth capacitor. Detailed Implementation

[0024] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0025] The implementation of this application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that the following implementations are merely illustrative and not an exhaustive list. Based on these implementations, those skilled in the art may replace, splice, or combine certain features or examples, and these should still be considered as the disclosure of this application.

[0026] like Figure 1 The diagram shows a battery charging circuit in related technologies. The charging circuit includes at least: a first protection integrated circuit element 11, a first semiconductor module 10, a capacitor, a resistor, and a negative temperature coefficient thermistor (NTC). The first semiconductor module 10 includes at least a sixth MOSFET 10-1 and a seventh MOSFET 10-2, which are connected. A second protection integrated circuit element 12 and a second semiconductor module 80 are also included. The second semiconductor module 80 includes at least an eighth MOSFET 80-1 and a ninth MOSFET 80-2, which are connected.

[0027] The first protection integrated circuit element 11 is connected to the first semiconductor module 10, and an eleventh capacitor 40 is connected in parallel to the first semiconductor module 10. The second protection integrated circuit element 12 is connected to the second semiconductor module 80, and a fourteenth capacitor 90 is connected in parallel to the second semiconductor module 80. The negative temperature coefficient thermistor is connected in series at the negative terminal of the power interface.

[0028] like Figure 1 As shown, the circuit from the positive terminal (B+) of the battery is divided into two branches, namely branch 3 and branch 4; the third branch passes through the seventh resistor 20 and is further divided into branch 3-1 and branch 3-2. Branch 3-1 is connected to the first pin (VCC) on the first protection integrated circuit element 11, and branch 3-2 is connected to the negative terminal (B-) of the battery through the tenth capacitor 30.

[0029] The four branches are divided into branch 4-1 and branch 4-2. Branch 4-1 is connected to the positive terminal (P+) of the power supply, and branch 4-2 is connected to the twelfth capacitor 50, and then to the negative terminal (P-) of the power supply. A negative temperature coefficient thermistor is connected after the twelfth capacitor 50. One end of the negative temperature coefficient thermistor is connected to the negative terminal (P-) of the power supply, and the other end is connected to the temperature sensor TH.

[0030] according to Figure 1 It is known that existing technologies employ dual-protection integrated circuit elements and dual MOSFET control to protect the circuit. Specifically, the first protection integrated circuit element 11 controls the switching on or off of the sixth MOSFET 10-1 and the seventh MOSFET 10-2 in the first semiconductor module 10, thereby stopping charging in case of overcharge protection. Furthermore, if the control of the sixth MOSFET 10-1 and the seventh MOSFET 10-2 in the first semiconductor module 10 by the first protection integrated circuit element 11 fails, a second protection integrated circuit element 11 is added to control the switching on or off of the eighth MOSFET 80-1 and the ninth MOSFET 80-2 in the second semiconductor module 80, thereby stopping charging in case of overcharge protection.

[0031] The existing technology uses dual-protection integrated circuit elements and dual-MOS transistor control to protect the circuit, which increases the cost of protecting the integrated circuit elements and MOS transistors.

[0032] Therefore, this application provides a battery charging protection circuit, including: a protection integrated circuit element, a battery interface, a power interface, a first circuit control element, and a second circuit control element; a first end of the protection integrated circuit element is connected to the battery through the battery interface; a second end of the protection integrated circuit element is connected to a charging power source through the power interface; the first circuit control element and the second circuit control element are connected in parallel between the second end of the protection integrated circuit element and the power interface; both the first circuit control element and the second circuit control element are turned on or off by a control signal from the protection integrated circuit element; the first end and the second end are pin interfaces in the protection integrated circuit element for connecting with other components; if the first circuit control element is in a non-operating state, the second circuit control element is turned on or off by the control signal from the protection integrated circuit element to protect the battery.

[0033] like Figure 2 The diagram shown is a battery charging protection circuit diagram proposed in an embodiment of this application. The battery charging protection circuit includes at least: a protection integrated circuit element 101, a first circuit control element, a second circuit control element, a battery interface, a power interface, a first on / off control circuit module 200, a thermistor module 300, a first voltage divider protection module 400, and a second voltage divider protection module 500.

[0034] The protection integrated circuit element 101 has six pins, namely:

[0035] The first pin is VDD (Voltage Drain-Drain). The first pin is connected to the positive terminal of the battery interface. The positive input of the battery provides the operating voltage for the protection integrated circuit element 101.

[0036] The second pin is CO (Charge Overcurrent). This pin is connected to the power interface, the first circuit control element, the second circuit control element, and the thermistor module. In the protection integrated circuit element 101, CO is the output of "Charge Overcurrent" (overcurrent detection). When an excessive charging current is detected, this pin will output a corresponding signal to stop or limit the charging process. The specific connections of the second pin will be explained later.

[0037] The third pin is DO (Digital Output). The third pin is connected to the first on / off control circuit module 200, which is used to control external components such as MOSFET switches to control the battery charging status.

[0038] The fourth pin is VSS (Voltage System Ground). This fourth pin is connected to the negative terminal of the battery and together with VDD, forms a power supply circuit.

[0039] The fifth pin is VINI (Voltage Initial Input). This fifth pin is connected to the third on / off control circuit module. VINI is an overcurrent detection port, which is used to monitor battery current or other important signal inputs.

[0040] Pin 6: V- (Negative Voltage Supply), pin 6 is grounded. In this embodiment, pin 6 is grounded after passing through resistor 5.

[0041] The first terminal of the protection integrated circuit element 101 is connected to the battery through the battery interface, that is, the first pin (VDD) of the protection integrated circuit element 101 is connected to the battery interface, and the battery interface is connected to the battery. The second terminal of the protection integrated circuit element is connected to the charging power supply through the power interface, that is, the second pin (CO) of the protection integrated circuit element 101 is connected to the battery through the battery interface.

[0042] The first circuit control element and the second circuit control element are connected in parallel between the second terminal of the protection integrated circuit element and the power interface. The second terminal is the second pin (CO), which is the charging overcurrent detection interface. The first circuit control element and the second circuit control element are controlled in parallel through the charging overcurrent detection interface. When the battery charge is greater than a first preset charge, the first circuit control element is controlled to disconnect. When the first circuit control element is in a non-operating state, the second circuit control element is controlled to disconnect. Based on this, by controlling the disconnection of dual circuit control elements with a single protection integrated circuit element, dual protection of the battery is achieved while saving costs, avoiding overcharging or over-discharging of the battery.

[0043] The following describes in detail the connection relationship between the protection integrated circuit element and the first circuit control element and the second circuit control element.

[0044] The first circuit control element is connected between the second end of the protection integrated circuit element and the negative power interface. When the battery power is greater than or equal to the preset power, the first circuit control element is controlled to disconnect or connect through the control signal of the protection integrated circuit element to protect the battery.

[0045] The second terminal of the protection integrated circuit element is connected to the positive power interface of the power supply. When the battery power is greater than or equal to the preset power, the control signal of the protection integrated circuit element controls the second circuit control element to disconnect or connect, so as to protect the battery.

[0046] The battery's charge level is greater than or equal to a preset charge level, which can be the battery's charge level when fully charged. When the battery is fully charged, the charging process needs to be disconnected. The first terminal (pin VDD) of the protection integrated circuit element is connected to the battery interface, and the second terminal (pin CO) of the protection integrated circuit element is connected to the negative power supply interface of the first circuit control element and to the positive power supply interface of the second circuit control element. Therefore, by using the first circuit control element and / or the second circuit control element, the charging of the battery is stopped.

[0047] The connection relationship of the first circuit control element is as follows:

[0048] The second terminal of the protection integrated circuit element 101 is a charging overcurrent detection interface, and the first circuit control element is a first MOS transistor 102. The first circuit control element is connected between the second terminal of the protection integrated circuit element and the power negative interface. Specifically, the first circuit of the first MOS transistor 102 is connected between the charging overcurrent detection interface of the protection integrated circuit element 101 and the power negative interface (P-). When the battery charge is greater than or equal to a first preset charge, the first circuit of the first MOS transistor 102 is disconnected by the control signal of the charging overcurrent detection interface. When the battery charge is less than or equal to a second preset charge, the first circuit of the first MOS transistor 102 is turned on by the control signal of the charging overcurrent detection interface. The first preset charge is greater than the second preset charge.

[0049] The charging overcurrent detection interface (CO) of the protection integrated circuit element 101 is connected to the power supply negative interface (P-) via a first circuit of the first MOS transistor 102. Specifically, the charging overcurrent detection interface (CO) of the protection integrated circuit element 101 is connected to the first interface (G1) of the first MOS transistor 102, and the second interface (S1) of the first MOS transistor 102 is connected to the power supply negative interface (P-). The first interface (G1) and the second interface (S1) are connected in series to form the first circuit of the first MOS transistor.

[0050] like Figure 2As shown, the first circuit of the first MOSFET 102 is formed by connecting G1, S1, and S1 in the first MOSFET 102. The charging overcurrent detection interface (CO) of the protection integrated circuit element 101 is connected to the G1 interface in the first MOSFET 102, and the S1 in the first MOSFET 102 is connected to the negative power supply interface (P-). When the battery charge is greater than or equal to a first preset charge, the battery is fully charged, i.e., at a high potential, and charging needs to be stopped. Therefore, the charging overcurrent detection interface (CO) sends a control signal to disconnect the first circuit, thus disconnecting the battery from the power supply. When the battery charge is less than or equal to a second preset charge, the battery is at a low potential. To prevent the battery charge from becoming too low, the discharging process needs to be stopped, and the charging process needs to be executed. Therefore, the charging overcurrent detection interface (CO) sends a control signal to connect the first circuit, connecting the first circuit to charge the battery.

[0051] The first preset battery level can be the battery level when it reaches 100%, and the second preset battery level can be the battery level when it is lower than the preset value (e.g., 10% of the battery capacity).

[0052] When the battery is overcharged, a discharge process needs to be performed on the battery, as follows:

[0053] The protection integrated circuit element 101 also includes a third terminal, which is a discharge current detection interface (DO). The discharge current detection interface (DO) of the protection integrated circuit element 101 is connected to the second circuit of the first MOS transistor 102 through the battery negative terminal interface (B-). When the battery charge is greater than or equal to a first preset charge, the control signal of the discharge current detection interface (DO) controls the second circuit of the first MOS transistor 102 to be turned on. When the battery charge is less than or equal to a second preset charge, the control signal of the charging overcurrent detection interface (DO) controls the first circuit of the second MOS transistor 102 to be turned off.

[0054] The discharge current detection interface (DO) of the protection integrated circuit element 101 is connected to the negative terminal interface of the battery via a second circuit of the first MOS transistor 102. Specifically, the discharge current detection interface (DO) of the protection integrated circuit element 101 is connected to the third interface (G2) of the first MOS transistor 102, and the fourth interface (S2) of the first MOS transistor is connected to the negative terminal interface (B-) of the battery. The third interface (G2) and the fourth interface (S2) are connected in series to form the second circuit of the first MOS transistor.

[0055] like Figure 2As shown, the second circuit of the first MOSFET 102 is formed by connecting G2, S2, and S2 in the first MOSFET 102. The discharge current detection interface (DO) of the protection integrated circuit element 101 is connected to the G2 interface in the first MOSFET 102, and the S2 in the first MOSFET 102 is connected to the negative terminal interface (B-) of the battery. When the battery charge is greater than or equal to a first preset charge, the battery is fully charged, i.e., at a high potential, and a discharge process needs to be performed. Therefore, the discharge current detection interface (DO) sends a control signal to connect the second circuit, thereby putting the battery in a discharge state. When the battery charge is less than or equal to the second preset charge, the battery is at a low potential. To prevent the battery charge from becoming too low, the discharge process needs to be stopped, and a charging process needs to be performed. Therefore, the discharge current detection interface (DO) sends a control signal to disconnect the second circuit, thus disconnecting the second circuit.

[0056] The above describes the connection relationship when the first MOSFET is in normal working condition.

[0057] Specifically, the protection integrated circuit element 101 and the first circuit control element, the first circuit control element including the first MOSFET 102, are connected. This can be understood as the protection integrated circuit element 101 being connected to the first MOSFET 102, that is, the second pin (CO) on the protection integrated circuit element 101 is connected to the G1 pin on the first MOSFET 102. Specifically, the 1-1 branch is connected to the first pin (VDD) of the protection integrated circuit element 101; the 1-1-2 branch, which branches off from the second pin (CO) of the protection integrated circuit element 101, is divided into two branches, 1-1-2-1 and 1-1-2-2. The 1-1-2-1 branch is connected to the thermistor module 300, and the 1-1-2-2 branch is connected to the G1 pin on the first MOSFET 102. The third pin is connected to the G2 pin on the first MOSFET 102.

[0058] Specifically, the fifth pin (VINI) on the protection integrated circuit element 101 is connected to the S2 pin on the first MOS transistor 102. An eighth capacitor 105 is connected before the fifth pin (VINI) is connected to the S2 pin on the first MOS transistor 102.

[0059] Specifically, a sixth resistor 700 is connected between the first MOS transistor 102 and the negative terminal of the battery interface. One end of the sixth resistor 700 is connected to the S2 pin of the first MOS transistor 102, and the other end is connected to the negative terminal of the battery interface.

[0060] If the first circuit control element (i.e., the first MOSFET) is in an abnormal operating state, the first circuit of the first MOSFET 102 is connected to the negative power supply interface (P-), and the second circuit of the first MOSFET 102 is connected to the negative battery interface (B-); the first circuit and the second circuit are disconnected respectively, and the negative power supply interface (P-) and the negative battery interface (B-) are connected, so that the first circuit control element is in a non-operating state.

[0061] When the power supply negative terminal (P-) and the battery negative terminal (B-) are connected, the first MOS transistor 102 is in a failure state. At this time, the second circuit control element needs to be turned on or off through the second pin (CO) to avoid the battery explosion when the battery is overcharged.

[0062] UL2054 certification requires that batteries not catch fire or explode under abnormal charging conditions (such as charging voltage up to 6V and current of 1C or 2C). This requires protective circuitry (such as...). Figure 1 The dual-IC dual-MOS design can still cut off the charging circuit in the event of a fault, ensuring that the battery is not damaged and remains in a safe state.

[0063] When the battery is undergoing UL2054 certification, if the first circuit control element (i.e., the first MOSFET) fails, the first MOSFET becomes a closed circuit, similar to a regular wire. In this case, the charging overcurrent detection interface (CO) cannot control the first MOSFET to cut off the circuit. Simultaneously, when the charging overcurrent detection interface (CO) of the protection integrated circuit element 101 detects that the battery voltage has reached the overcharge protection voltage range (4.26V~4.30V), it controls the second circuit control element (i.e., the second MOSFET) to turn on or off, thereby protecting the battery and preventing the battery voltage from exceeding the overcharge protection voltage range when the battery charging current multiple is 1C / 2C. Here, 1C indicates that the current value is equal to the battery's rated capacity (e.g., if the battery capacity is 1000mAh, 1C = 1000mA). 2C indicates that the current value is twice the rated capacity (e.g., 2000mA).

[0064] In order to achieve UL2054 certification, the protection circuit can still cut off the charging circuit in case of failure. It adopts the charging overcurrent detection interface (CO) of the protection integrated circuit element 101 connected in parallel with the first circuit control element and the second circuit control element.

[0065] Specifically, the connection relationship of the second circuit control element is as follows:

[0066] The protection integrated circuit element 101 includes a charging overcurrent detection interface (CO), and the second circuit control element is a second MOSFET 103. The second MOSFET 103 includes a third circuit and a fourth circuit connected in series. The second terminal of the protection integrated circuit element 101 is connected to the power supply positive interface (P+). Specifically, the third circuit of the second MOSFET 103 is connected to the charging overcurrent detection interface (CO) of the protection integrated circuit element 101, and the fourth circuit of the second MOSFET 103 is connected to the power supply positive interface. The control signal of the charging overcurrent detection interface (CO) controls the third circuit and the fourth circuit of the second MOSFET 103 to be turned on or off simultaneously.

[0067] like Figure 2 As shown, the third circuit in the second MOSFET 103 is formed by G1, S1, and S1. The fourth circuit is formed by G2, S2, and S2. The third interface (G1) and the fourth interface (G2) in the second MOSFET 103 are connected in series, thus the second MOSFET 103 has only one charging circuit. When the battery charge is greater than or equal to a first preset charge, the charging overcurrent detection interface (CO) detects that the battery is in an overcharge state and sends a control signal to control the second MOSFET 103 to be in the off state.

[0068] To reduce the battery's charge, this application employs a diode connected in parallel with the second MOSFET 103 to achieve the discharge process. Specifically, a diode 104 is connected in parallel with the second MOSFET 103. One end of the diode 104 is connected to the battery's positive terminal (B+), and the other end of the diode 104 is connected to the power supply's positive terminal (P+). The diode 104 performs the battery discharge process when the battery's charge is greater than or equal to a first preset charge and the second MOSFET 103 is in the off state.

[0069] When the battery is charging, the current flows from the positive power supply interface (P+) to the positive battery interface (B+); here, the current flows from the positive power supply interface (P+) through the second MOSFET 103 to the positive battery interface (B+). When the battery charge exceeds a first preset charge level, the overcurrent detection interface (CO) detects that the battery is in an overcharge state and sends a control signal to control the second MOSFET 103 to be in the off state. Since the third and fourth interfaces of the second MOSFET 103 are connected in series, the second MOSFET 103 has a discharge function after being disconnected. A diode has unidirectional conduction function; therefore, a diode is added here. When the battery is discharging, the current flows from the positive battery interface (B+) through the diode to the positive power supply interface (P+).

[0070] The above describes the process of controlling the first circuit control element and the second circuit control element through the charging overcurrent detection interface (CO) of a protection integrated circuit element 101. This enables the battery to be protected even when the first power control element fails, by connecting and disconnecting the second power control element.

[0071] In addition, it also includes: a thermistor module, the thermistor module comprising: a negative temperature coefficient thermistor (NTC) and a fifth MOSFET, the NTC being connected to the fifth MOSFET; the fifth MOSFET is used to disconnect when the battery charge is greater than or equal to a first preset charge, thereby disconnecting the circuit between the NTC and the power interface, and to connect when the battery charge is less than the first preset charge, thereby connecting the NTC and the power interface.

[0072] The battery charging protection circuit further includes a thermistor module 300, one end of which is connected to the second pin, and the other end of which is connected to the power interface.

[0073] Specifically, the second pin (CO) on the protection integrated circuit element 101 is connected to the thermistor module 300 via a wire, thereby connecting the protection integrated circuit element 101 to the thermistor module 300. The other end of the thermistor module 300 is connected to the negative terminal of the power interface.

[0074] The thermistor module 300 includes: a negative temperature coefficient thermistor NTC301 and a second on / off control circuit module; the NTC301 is connected to the second on / off control circuit module; the second on / off control circuit module is used to disconnect when the battery is fully charged, so as to disconnect the circuit between the NTC301 and the power interface, and to connect when the battery is not fully charged, so as to connect the NTC301 and the power interface.

[0075] Specifically, the thermistor module 300 includes a negative temperature coefficient thermistor NTC301 and a second on / off control circuit module, with the NTC301 connected in series with the second on / off control circuit module. When the battery is fully charged, the circuit of the second on / off control circuit module is disconnected, meaning the circuit between the NTC301 and the power interface is broken, and the power supply will no longer charge the battery. When the battery is partially charged, the circuit of the second on / off control circuit module is turned on, the connection between the NTC301 and the power interface is established, and the power supply will continue to charge the battery.

[0076] The NTC301 is an electronic component whose resistance decreases as temperature increases. These components are typically made of ceramic materials composed of metal oxides such as manganese, nickel, cobalt, and copper, and their resistance-temperature characteristic curves exhibit a pronounced negative slope. The NTC301 is commonly used for temperature measurement; because there is a stable functional relationship between resistance and temperature, the corresponding temperature value can be calculated by measuring the change in resistance within a certain range.

[0077] The second on / off control circuit module includes a fifth MOS transistor 302, which is an N-type MOS transistor. The fifth MOS transistor 302 is used to turn off when the protection integrated circuit element 101 is at a low potential, thereby disconnecting the circuit between the protection integrated circuit element 101 and the power interface.

[0078] When the battery is fully charged, the second pin (CO) changes from high to low, and the fifth MOSFET 302 is at a low level, meaning it is turned off and its circuit is disconnected. This disconnects the circuit between the NTC301 and the power interface, and the NTC301 does not provide resistance feedback to the system. The system's charging management IC then cuts off the continuous voltage supply to the battery. When the battery is partially charged, the second pin (CO) is high, and the fifth MOSFET 302 is high, meaning it is turned on and its circuit is conducting. This connects the NTC301 and the power interface, allowing the NTC301 to provide normal resistance feedback to the system and continue charging the battery. By controlling the switching of the fifth MOSFET 302 via voltage, the system controls whether the NTC301 can provide normal feedback to the system, thus linking the system's charging needs to ensure safer battery charging.

[0079] Specifically, the second on / off control circuit module includes a fifth MOSFET 302, which is an N-type MOSFET. The gate (G3) of the fifth MOSFET 302 is connected to the second pin (CO) of the protection integrated circuit element 101. The source (S3) of the fifth MOSFET 302 is connected to the negative terminal (P-) of the power interface, so that the fifth MOSFET 302 is connected to the power interface. The drain (D3) of the fifth MOSFET 302 is connected to a resistor box 305 and the NTC 301. The resistor box 305 is connected between the drain (D3) of the fifth MOSFET 302 and the NTC 301. The other end of the NTC 301 is connected to a temperature sensor, that is, the positive terminal of the NTC 301 is connected to the positive pin of the temperature sensor, i.e., connected to TH+.

[0080] Specifically, a sixth capacitor 303 is connected in parallel to the fifth MOS transistor 302, that is, one end of the sixth capacitor 303 is connected to the drain (D3) of the fifth MOS transistor 302, and the other end is connected to the source (S3) of the fifth MOS transistor 302.

[0081] A seventh capacitor 304 is also connected to the connection between the fifth MOS transistor 302 and the second pin (CO) on the protection integrated circuit element 101, that is, the seventh capacitor 304 is connected between the fifth MOS transistor 302 and the second pin (CO) on the protection integrated circuit element 101.

[0082] In addition, a first on / off control circuit module 200 is connected between the battery interface and the protection integrated circuit element 101. The first on / off control circuit module 200 is used to disconnect when the battery power is less than a preset value, so as to disconnect the circuit between the protection integrated circuit element 101 and the battery interface to protect the battery.

[0083] The first on / off control circuit module 200 includes a third MOSFET 201 and a fourth MOSFET 202 connected to each other. The third MOSFET 201 is an N-type MOSFET, and the fourth MOSFET 202 is a P-type MOSFET. The gate of the fourth MOSFET 202 is connected to the protection integrated circuit element 101, and its drain is grounded. The gate of the third MOSFET 201 is connected to the source of the fourth MOSFET 202, and its drain is connected to the battery interface. The fourth MOSFET 202 is used to turn on when the protection integrated circuit element 101 is at a low potential, thereby turning off the third MOSFET 201 when it is grounded, thus disconnecting the circuit between the protection integrated circuit element 101 and the battery interface. The protection integrated circuit element 101 is at a high potential when the battery is fully charged, and at a low potential when the battery charge is less than a preset value.

[0084] The main characteristics of MOSFETs are their extremely high input impedance, resulting in very low drive current and fast switching speed. They are widely used in various digital circuits, analog circuits, and power converters, such as power management, microprocessor internal logic, communication equipment, and motor drives. In battery protection circuits, MOSFETs are also commonly used as high-side or low-side switches to achieve precise current control and overcurrent protection.

[0085] A third resistor 202-1 and a fifth capacitor 202-2 are connected in parallel on the fourth MOSFET 202. The third pin is connected to the gate (G2) of the fourth MOSFET 202, the drain (D2) of the fourth MOSFET 202 is grounded, and the source (S2) of the fourth MOSFET 202 is connected to the gate of the third MOSFET 201.

[0086] A second resistor 201-1 and a fourth capacitor 201-2 are connected in parallel on the third MOS transistor 201. The gate (G1) of the third MOS transistor 201 is connected to the source (S2) of the fourth MOS transistor 202. The drain (D1) of the third MOS transistor 201 is connected to the battery interface. The source (S1) of the third MOS transistor 201 is connected to the first pin of the protection integrated circuit element 101.

[0087] Specifically, such as Figure 2 As shown, the circuit originates from the source (S1) of the third MOS transistor 201 and branches into two branches: branch 1 and branch 2. Branch 1, after passing through the fourth resistor 600, further branches into branch 1-1 and branch 1-2. Branch 1-1 is connected to the first pin (VDD) of the protection integrated circuit element 101, and branch 1-2 is connected to the second voltage divider protection module 500. Branch 2 is further divided into branch 2-1 and branch 2-2. Branch 2-1 is connected to the positive terminal of the power interface, and branch 2-2 is connected to the first voltage divider module 400.

[0088] One end of the first voltage divider protection module 400 is connected to the battery interface and / or the power interface; the other end of the first voltage divider protection module 400 is grounded. The first voltage divider protection module 400 includes a first resistor 401 and a first capacitor 402; the first resistor 401 and the first capacitor 402 are connected.

[0089] Specifically, the first voltage divider protection module 400 is mainly used to prevent overvoltage from damaging sensitive electronic components or equipment. In situations where power input, signal lines, or other areas may be subjected to excessively high voltage surges, the voltage divider reduces the input voltage to a safe operating range. In this embodiment, the first voltage divider protection module 400 includes a first resistor 401 and a second capacitor 402, which are connected in series. Specifically, the first resistor 401 is located before the second capacitor 402, one end of the second capacitor 402 is connected to the first resistor 401, and the other end of the second capacitor 402 is grounded.

[0090] The first voltage divider protection module 400 is connected to the power input circuit to divide the power input voltage. When a high voltage signal enters, the first voltage divider protection module 400 will distribute the voltage according to its resistance ratio, so that the subsequent circuit receives a safe voltage with a reduced amplitude.

[0091] Specifically, branch 2 originates from the positive terminal of the battery interface, meaning one end of branch 2 is connected to the positive terminal of the battery interface. Branch 2-1 ultimately returns to the positive terminal of the power supply, meaning one end of branch 2-1 is connected to the positive terminal of the power supply. For example... Figure 2 As shown, one end of the first voltage divider protection module 400 can be connected to the positive terminal of the battery interface, or to the positive terminal of the power interface, or simultaneously connected to the circuit of the positive terminals of both the battery interface and the power interface.

[0092] The battery charging protection circuit further includes a second voltage divider protection module 500. One end of the second voltage divider protection module 500 is connected to the battery interface through the third MOS transistor 201, and the other end is connected to the protection integrated circuit element 101. The second voltage divider protection module 500 includes a second capacitor 501 and a third capacitor 502, which are connected in series.

[0093] Specifically, branch 1-2 is connected to the second voltage divider protection module 500, and after passing through the second voltage divider protection module 500, branch 1-2 is connected to the negative terminal of the battery interface. In this embodiment, the second capacitor 501 and the third capacitor 502 are connected in series to form a redundant design, which can improve the reliability and stability of the system.

[0094] In this application, the second capacitor 501 and the third capacitor 502 are connected in series to form a redundant design, which can increase the system design margin. After connecting the second capacitor 501 and the third capacitor 502 in series, the equivalent total capacitance value is equal to the capacitance value required by the protection integrated circuit element 101. For example, if the capacitance value of the second capacitor 501 is C1 and the capacitance value of the third capacitor 502 is C2, then the total capacitance value is C:

[0095] C = (C1 × C2) / (C1 + C2).

[0096] Therefore, equivalent filter capacitors can be provided to effectively suppress power supply ripple and improve the stability of the output voltage. It also provides fault isolation and backup; when one capacitor fails or degrades, the other healthy capacitor can continue to operate, ensuring the normal operation of the charging circuit. This design reduces the risk of the entire charging system being interrupted due to the failure of a single capacitor. It also extends lifespan and improves maintenance convenience. By connecting the second capacitor 501 and the third capacitor 502 in series, the workload of the capacitors can be distributed, thereby reducing the stress on individual capacitors and potentially extending their lifespan. Furthermore, when capacitors need to be replaced, the entire charging process can be undone online via hot-swapping, improving maintenance efficiency. It also enhances shock resistance. In situations with transient high voltages or frequent load changes, the redundant design helps absorb these high voltage surges and uncertainties, reducing the impact on the battery charging process and protecting the circuit from damage.

[0097] When the battery is fully charged, the third pin (DO) of the protection integrated circuit element 101 goes high. At this time, the fourth MOSFET 202 in the first on / off control circuit module 200, which is connected to the third pin (DO) of the protection integrated circuit element 101, goes high, thus turning off the fourth MOSFET 202, meaning the circuit on the fourth MOSFET is disconnected. Meanwhile, the third MOSFET 201, which is connected to the fourth MOSFET 202, goes high, thus turning on the third MOSFET 201, making the circuit on the third MOSFET 201 conduct, meaning the third MOSFET 201 can work normally. When the battery charge is less than a preset value, that is, when the battery charge reaches the minimum requirement, the third pin (DO) changes from a high potential to a low potential. At this time, the fourth MOSFET 202 turns on, that is, the circuit on the fourth MOSFET is turned on. Since the fourth MOSFET is connected to GND, the fifth MOSFET turns off. The circuit on the third MOSFET 201 is disconnected. The circuit on the third MOSFET 201 is disconnected from the circuit on the protection integrated circuit element 101, that is, it will not continue to consume the battery charge, reducing the risk of the battery being over-discharged.

[0098] The circuit between the third MOSFET 201 and the protection integrated circuit element 101 is disconnected, thereby disconnecting the circuit between the protection integrated circuit element 101 and the battery interface. This prevents the protection integrated circuit element 101 from continuing to consume power, ensuring that when the battery charge is below a preset value, it stops consuming its own power, thus avoiding the risk of the battery IC being over-discharged due to accelerated power consumption. In this embodiment, the main circuit of the IC is completely disconnected by controlling the switching of the third MOSFET 201 and the fourth MOSFET 202 on the first on / off control circuit module 200 via voltage.

[0099] It should be noted that, in the embodiments of this application, the values ​​of the capacitors and resistors involved can be set according to the actual working conditions.

[0100] In addition to the above embodiments, this application can also switch the fifth MOS transistor 302 in the thermistor module 300 controlled by the second pin (CO) and the third pin (DO) on the protection integrated circuit element 101 and the third MOS transistor 201 and the fourth MOS transistor 202 in the first on / off control circuit module 200. For specific details, please refer to the above embodiments.

[0101] This application provides a battery charging protection circuit, including: a protection integrated circuit element, a battery interface, a power interface, a first circuit control element, and a second circuit control element. A first terminal of the protection integrated circuit element is connected to a battery through the battery interface; a second terminal of the protection integrated circuit element is connected to a charging power source through the power interface. The first circuit control element and the second circuit control element are connected in parallel between the second terminal of the protection integrated circuit element and the power interface. Both the first and second circuit control elements are turned on or off by a control signal from the protection integrated circuit element. The first and second terminals are pin interfaces in the protection integrated circuit element used for connecting to other components. If the first circuit control element is in a non-operating state, the control signal from the protection integrated circuit element controls the on / off state of the second circuit control element to protect the battery. This application protects the battery by connecting the first and second circuit control elements in parallel between the protection integrated circuit element and the power interface, using a dual circuit control element controlled by a single protection integrated circuit element.

[0102] Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A battery charging protection circuit, characterized in that, include: Protect integrated circuit components, battery interface, power interface, first circuit control component, and second circuit control component; The first end of the protection integrated circuit element is connected to the battery through the battery interface; The second end of the protection integrated circuit element is connected to the charging power supply through the power interface. The first circuit control element and the second circuit control element are connected in parallel between the second end of the protection integrated circuit element and the power interface. The first circuit control element and the second circuit control element are both turned on or off by the control signal of the protection integrated circuit element. The first end and the second end are respectively pin interfaces in the protection integrated circuit element used for connecting with other components. If the first circuit control element is in a non-operating state, the control signal of the protection integrated circuit element controls the second circuit control element to turn on or off, so as to protect the battery.

2. The battery charging protection circuit according to claim 1, characterized in that, Specifically, the first circuit control element and the second circuit control element are connected in parallel between the second terminal of the protection integrated circuit element and the power interface. The first circuit control element is connected between the second end of the protection integrated circuit element and the negative power interface. When the battery power is greater than or equal to the first preset power, the first circuit control element is controlled to disconnect or connect through the control signal of the protection integrated circuit element to protect the battery. The second terminal of the protection integrated circuit element is connected to the positive power interface of the power supply. When the battery power is greater than or equal to the first preset power, the control signal of the protection integrated circuit element controls the second circuit control element to disconnect or connect, so as to protect the battery.

3. The battery charging protection circuit according to claim 2, characterized in that, The second terminal of the protection integrated circuit element is a charging overcurrent detection interface, and the first circuit control element is a first MOS transistor. The first circuit control element is connected between the second terminal of the protection integrated circuit element and the negative power supply interface, specifically: A first circuit of a first MOS transistor is connected between the charging overcurrent detection interface of the protection integrated circuit element and the negative terminal interface of the power supply. When the battery charge is greater than or equal to a first preset charge, the first circuit of the first MOS transistor is disconnected by the control signal of the charging overcurrent detection interface. When the battery charge is less than or equal to a second preset charge, the first circuit of the first MOS transistor is turned on by the control signal of the charging overcurrent detection interface. The first preset charge is greater than the second preset charge.

4. The battery charging protection circuit according to claim 3, characterized in that, A first circuit with a first MOSFET is connected between the charging overcurrent detection interface of the protection integrated circuit element and the negative power supply interface, specifically: The charging overcurrent detection interface of the protection integrated circuit element is connected to the first interface of the first MOS transistor, and the second interface of the first MOS transistor is connected to the negative power supply interface. The first interface and the second interface are connected in series to form the first circuit of the first MOS transistor.

5. The battery charging protection circuit according to claim 3, characterized in that, The protection integrated circuit element also includes a third terminal, which is a discharge current detection interface; A second circuit of the first MOS transistor is connected between the discharge current detection interface of the protection integrated circuit element and the negative terminal interface of the battery. When the battery charge is greater than or equal to a first preset charge, the control signal of the discharge current detection interface controls the second circuit of the first MOS transistor to be turned on. When the battery charge is less than or equal to a second preset charge, the control signal of the charging overcurrent detection interface controls the second circuit of the first MOS transistor to be turned off.

6. The battery charging protection circuit according to claim 5, characterized in that, A second circuit with a first MOSFET is connected between the discharge current detection interface of the protection integrated circuit element and the negative terminal interface of the battery. Specifically: The discharge current detection interface of the protection integrated circuit element is connected to the third interface of the first MOS transistor, and the fourth interface of the first MOS transistor is connected to the negative terminal interface of the battery. The third interface and the fourth interface are connected in series to form the second circuit of the first MOS transistor.

7. The battery charging protection circuit according to claim 1, characterized in that, The first circuit control element is a first MOSFET, which includes a first circuit and a second circuit. The first circuit of the first MOSFET is connected to the negative terminal of the power supply, and the second circuit of the first MOSFET is connected to the negative terminal of the battery. The first circuit and the second circuit are disconnected respectively, and the negative terminal of the power supply and the negative terminal of the battery are connected, so that the control element of the first circuit is in a non-operating state.

8. The battery charging protection circuit according to claim 2, characterized in that, The protection integrated circuit element includes a charging overcurrent detection interface, and the second circuit control element is a second MOS transistor, which includes a third circuit and a fourth circuit connected in series. The second circuit control element is connected between the second terminal of the protection integrated circuit element and the positive power supply interface, specifically: The third circuit of the second MOS transistor is connected to the charging overcurrent detection interface of the protection integrated circuit element, and the fourth circuit of the second MOS transistor is connected to the positive power supply interface. The control signal of the charging overcurrent detection interface controls the third and fourth circuits of the second MOS transistor to be turned on or off simultaneously.

9. The battery charging protection circuit according to claim 8, characterized in that, Also includes: A diode connected in parallel with the second MOSFET, one end of which is connected to the positive terminal of the battery, and the other end of which is connected to the positive terminal of the power supply. The diode performs the battery discharge process when the battery charge is greater than or equal to a first preset charge and the second MOS transistor is in the off state.

10. The battery charging protection circuit according to claim 1, characterized in that, Also includes: A thermistor module, comprising: a negative temperature coefficient thermistor (NTC) and a fifth MOSFET, wherein the NTC is connected to the fifth MOSFET; The fifth MOSFET is used to disconnect when the battery charge is greater than or equal to a first preset charge, thereby disconnecting the circuit between the NTC and the power interface, and to connect when the battery charge is less than the first preset charge, thereby connecting the NTC and the power interface.

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