A charging circuit and earphone charging box

Abstract

The application discloses a charging circuit and an earphone charging box, and relates to the technical field of charging circuits.The charging circuit comprises a first charging module, a second charging module and a master control module.The first charging module comprises a first charging chip and a first temperature sensor arranged adjacently, the first charging chip is connected with a battery to supply power to the battery, and the first temperature sensor is used for detecting the temperature of the first charging chip.The second charging module comprises a second charging chip and a second temperature sensor arranged adjacently, the second charging chip is connected with the first charging chip, and the second temperature sensor is used for detecting the temperature of the second charging chip.The master control module is used for controlling the charging speed of the first charging chip according to the temperature of the first charging chip and controlling the charging speed of the first charging chip according to the temperature of the second charging chip.The application aims to reduce the temperature of the charging chip and the battery when the temperature of the battery is high, so that the battery of the charging box can be fully charged.

Description

Technical Field

[0001] This application relates to the field of charging circuit technology, and in particular to a charging circuit and an earphone charging case. Background Technology

[0002] When the earphone charging case is charged via USB or wireless charging, the temperature of the charging chip and battery will gradually rise. When the battery temperature rises, the charging voltage of the battery will drop. For example, when the battery temperature is detected to be between 45℃ and 60℃, the battery can only be charged to 4.2V (the normal full charging voltage of the battery is 4.4V), so it cannot be fully charged. When the battery temperature is detected to be greater than 60℃, the charging voltage of the earphone charging case will drop further or even stop charging. Utility Model Content

[0003] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to provide a charging circuit and an earphone charging case, which aims to reduce the temperature of the charging chip and the battery when the battery temperature is high, so that the charging case battery can be fully charged.

[0004] In a first aspect, embodiments of this application provide a charging circuit, including a first charging module, a second charging module, and a main control module; The first charging module includes a first charging chip and a first temperature sensor disposed adjacent to each other. The first charging chip is connected to the battery to supply power to the battery, and the first temperature sensor is used to detect the temperature of the first charging chip. The second charging module includes a second charging chip and a second temperature sensor disposed adjacent to each other. The second charging chip is connected to the first charging chip to supply power to the battery through the first charging chip. The second temperature sensor is used to detect the temperature of the second charging chip. The main control module is connected to the first charging chip, the first temperature sensor, and the second temperature sensor respectively, and is used to control the charging speed of the first charging chip according to the temperature of the first charging chip, and to control the charging speed of the first charging chip according to the temperature of the second charging chip.

[0005] According to the technical solution of the embodiments of this application, at least the following beneficial effects are achieved: a temperature sensor is added next to the first charging chip and the second charging chip on the motherboard. By detecting the temperature of the charging chip, the charging current can be reduced when the chip temperature is high, thereby reducing the temperature of the charging chip and the battery, so that the charging box battery can be fully charged.

[0006] According to some embodiments of this application, the first charging module further includes a power connector for connecting to a first external power source and a charging protection chip, wherein the charging protection chip is connected to the power connector and the first charging chip respectively.

[0007] According to some embodiments of this application, the second charging module further includes a switching transistor connected between the second charging chip and the first charging chip. The second charging chip is used to connect to a second external power source, and the switching state of the second external power source supplying power to the battery is controlled by the on / off state of the switching transistor.

[0008] According to some embodiments of this application, the second charging chip includes a charging voltage node terminal, which is respectively connected to the power connector and the control pin of the switching transistor; when the power connector is not connected to the first external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a low level, the second charging chip is running and the switching transistor is turned on.

[0009] According to some embodiments of this application, when the power connector is connected to the first external power source, the charging voltage node and the control pin of the switching transistor are at a high level, the second charging chip stops operating and the switching transistor is turned off.

[0010] According to some embodiments of this application, when the power connector is connected to the first external power supply and the second charging module is connected to the second external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a high level, the second charging chip stops operating and the switching transistor is turned off.

[0011] According to some embodiments of this application, the main control module is connected to the first temperature sensor and the second temperature sensor respectively through a first port, so as to control the detection switches of the first temperature sensor and the second temperature sensor through the first port. The main control module is also connected to the first temperature sensor through a second port to obtain the temperature of the first charging chip. The main control module is also connected to the second temperature sensor through a third port to obtain the temperature of the second charging chip.

[0012] According to some embodiments of this application, a third temperature sensor is also included, disposed adjacent to the battery, the third temperature sensor being used to detect the temperature of the battery.

[0013] According to some embodiments of this application, the first charging chip includes a PWM module and an NVDC module, and the first charging chip is used to adjust the charging current to charge the battery through the PWM module and the NVDC module.

[0014] Secondly, embodiments of this application provide an earphone charging case, a charging circuit as described above, and an earphone charging interface connected to the charging circuit for charging the earphones.

[0015] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0016] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic block diagram of the charging circuit provided in one embodiment of this application; Figure 2 This is a circuit diagram of a charging circuit provided in another embodiment of this application. Detailed Implementation

[0018] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0019] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0020] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features. In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0021] The present application will be further described below with reference to the accompanying drawings.

[0022] like Figure 1 As shown, Figure 1 This is a schematic block diagram of a charging circuit provided in one embodiment of the present application. The charging circuit includes a first charging module, a second charging module, and a main control module. The first charging module includes a first charging chip and a first temperature sensor disposed adjacent to each other. The first charging chip is connected to the battery to supply power to the battery, and the first temperature sensor is used to detect the temperature of the first charging chip. The second charging module includes a second charging chip and a second temperature sensor disposed adjacent to each other. The second charging chip is connected to the first charging chip to supply power to the battery through the first charging chip, and the second temperature sensor is used to detect the temperature of the second charging chip. The main control module is connected to the first charging chip, the first temperature sensor, and the second temperature sensor, respectively, and is used to control the charging speed of the first charging chip according to the temperature of the first charging chip, and to control the charging speed of the first charging chip according to the temperature of the second charging chip.

[0023] It is understandable that electronic devices powered by batteries do not require an external power source to operate normally. Instead, their internal batteries maintain the normal operation of the electronic devices. Furthermore, the batteries of electronic devices can be charged by connecting to an external power source. Therefore, electronic devices include charging circuits, which include batteries and charging modules.

[0024] In this embodiment, the charging circuit includes a first charging module and a second charging module. This means that the electronic device using this charging circuit can have two different charging methods. The first and second charging modules correspond to different charging methods. For example, the first charging module can be a wired charging module, such as a USB-PD module or a QC fast charging module, transmitting power through a physical interface. The second charging module can be a wireless charging module, such as a Qi standard module, based on the principle of electromagnetic induction, achieving energy transfer through coils at the transmitting and receiving ends, and integrating an MCU for communication handshake and efficiency optimization. This dual-module design meets the user's needs in different environments.

[0025] In this embodiment, the first charging module includes a first charging chip and a first temperature sensor disposed adjacent to each other. That is, the first temperature sensor is physically located in the vicinity of the first charging chip. Here, the placement of the first temperature sensor typically requires maintaining a certain distance from the heat-generating core area of ​​the charging chip, for example, within 3mm, and using a filling material with high thermal conductivity to ensure sufficiently low thermal resistance. In actual PCB layout, the first temperature sensor also needs to avoid the heat dissipation via array of the charging chip to prevent uneven thermal distribution from causing measurement deviations. It should also avoid being installed in airflow dead zones, as air convection cooling will significantly affect the temperature gradient. The traces of the first temperature sensor must also be kept away from the high-frequency switching nodes of the charging chip, maintaining a spacing of at least 5 times the line width to prevent coupling noise, and differential signal transmission of temperature data can be used.

[0026] In addition, the first temperature sensor needs a certain basic accuracy and a certain sampling rate. For example, the first temperature sensor needs to meet a basic accuracy of ±0.5℃ and have a sampling rate of at least 10Hz to capture rapid transient temperature rises. The first temperature sensor can be an NTC thermistor, a digital sensor, or other similar types of sensor.

[0027] In this embodiment, the first charging chip is connected to the battery to supply power to the battery. This can be done by directly connecting the first charging chip to an external power source and then supplying power to the battery through the first charging chip, or by connecting the first charging chip to an external power source through a power connector in the charging circuit and then connecting the power connector to the first charging chip and supplying power to the battery through the first charging chip.

[0028] Specifically, external power inputs, such as USB PD adapters or wireless charging receivers, are directly connected to the power input pins of the first charging chip. The voltage and current are regulated by the power conversion module integrated within the chip before supplying power to the battery. This minimizes the power path and reduces power loss in intermediate stages. The first charging module may also include an input-level overvoltage protection circuit, a dynamic input current regulation module that automatically adjusts the charging power based on the power supply capacity, and a four-wire Kelvin detection connection between the chip and the battery. Using a power connector in the charging circuit as an intermediary node, external power is first connected to a standardized interface and then transmitted to the first charging chip via the connector's power distribution network. This provides high scalability and ease of maintenance for the circuit. The selection of the power connector requires comprehensive consideration of contact resistance, insertion / removal life, and EMC performance.

[0029] In this embodiment, the second charging module includes a second charging chip and a second temperature sensor disposed adjacent to each other. Here, the setting requirements of the second temperature sensor can be the same as those of the first temperature sensor, or they can be specifically set according to the requirements and characteristics of the second charging chip.

[0030] In addition, the second charging chip is connected to the first charging chip so that the battery is powered through the first charging chip. That is to say, the second charging chip is not directly connected to the battery, but is connected to the first charging chip and then the battery is powered through the first charging chip. Here, the second charging chip can be directly connected to an external power source, or it can be connected to an external power source through a power connector in the charging circuit, and then the power connector is connected to the second charging chip.

[0031] Understandably, the second charging chip is not directly connected to the battery. Instead, it connects to the first charging chip, which then supplies power to the battery. In this case, the first charging chip can be a more integrated battery management IC with complete charging management functions and integrated power path management functions, which can intelligently allocate the energy flow between the input power and the battery. The second charging chip can be a chip that can convert the input energy into an intermediate voltage that meets the requirements of the first charging chip, but it does not directly handle the fine management tasks related to the battery. For example, the second charging chip can be a wireless charging receiver IC that converts the sensed AC power into DC voltage and then sends it to the first charging chip for further processing.

[0032] Understandably, the second charging chip's decision to bypass the battery and instead connect via the first charging chip is primarily based on considerations such as power path optimization, safety management, and reduced system complexity. For example, when a device is simultaneously connected to a USB cable and a wireless charger, the system needs to select the optimal input source based on factors such as power output and power stability. This complex decision-making logic is best handled by the first charging chip, which is dedicated to battery management. If the second charging chip were directly connected to the battery, it would not only lead to competition among multiple power inputs but also cause the system to lose centralized control over the charging process.

[0033] In addition, a complete protection circuit with safety certification can be built into the first charging chip. If each input source is directly connected to the battery, the same protection circuit needs to be deployed repeatedly on each charging path, which increases costs and introduces more points of failure. Furthermore, functions such as battery charging status monitoring, cycle counting, and aging compensation all require accurate measurement of battery end parameters. If multiple charging chips work in parallel, it will cause deviations in battery status estimation.

[0034] In this embodiment, the main control module is connected to the first charging chip, the first temperature sensor, and the second temperature sensor. Here, the main control module can communicate with the first charging chip through digital interfaces such as I2C, SPI, or SMBus to configure charging parameters and read real-time status. For example, in a USB PD fast charging system, the main control MCU interacts with the first charging chip through the CC line to dynamically adjust the charging protocol. If the first and second temperature sensors are digital sensors, the main control module can use a single bus or I2C interface to directly read temperature data. If the first and second temperature sensors are analog sensors, the main control module can be connected through the ADC input pin and use a voltage divider circuit to perform temperature-voltage conversion.

[0035] Understandably, in compact electronic devices, such as smartphones and TWS earphones, the second charging chip (wireless charging receiver chip) and the first charging chip (wired charging chip) may share the same heat dissipation path. For example, during wireless charging, the heat from the receiving coil and rectifier circuit will be conducted to the motherboard, causing the temperature around the first charging chip to rise. If only the temperature of the first charging chip is monitored, the overall thermal risk may not be detected in time. Therefore, the charging speed of the first charging chip can be controlled based on the temperature of the second charging chip. Furthermore, when the device uses dual-mode charging simultaneously, the main control module needs to intelligently allocate the input power according to the temperature rise of both. For example, if the temperature of the second charging chip soars due to poor heat dissipation, the main control module can reduce the current of the first charging chip to prevent the total system heat dissipation from exceeding the safety limit.

[0036] Understandably, the temperature protection built into the charging chip is usually a fixed threshold, while the main control module can dynamically adjust the protection threshold according to real-time operating conditions. For example, in a high-temperature environment, the main control module can reduce the charging current in advance instead of waiting for the chip to hard shut down, thereby extending battery life. Therefore, the first temperature sensor and the second temperature sensor can be connected to the main control module instead of directly to the charging chip.

[0037] In another embodiment of the charging circuit provided in this application, the first charging module further includes a power connector for connecting to a first external power source and a charging protection chip OVP&OCP, wherein the charging protection chip OVP&OCP is connected to the power connector and the first charging chip ChargerIC, respectively.

[0038] refer to Figure 2 , Figure 2This is a circuit diagram of a charging circuit provided in another embodiment of this application. The first charging module further includes a power connector for connecting to a first external power source and a charging protection chip OVP&OCP. The power connector is a USB socket, meaning that the first charging module can be a charging module using USB wired charging. The charging protection chip OVP&OCP is an overvoltage and overcurrent protection chip of model SGM2536PR. The first charging chip ChargerIC can be a charging management chip of model SY8809. The first temperature sensor can be a thermistor SY8809_NTC. The charging protection chip OVP&OCP is connected to the power connector and the first charging chip ChargerIC respectively. Thus, the charging protection chip OVP&OCP can provide overvoltage and overcurrent protection for the first charging module.

[0039] For example, an adapter or DC power supply connects to the power connector via a USB cable. The battery is charged via an overvoltage and overcurrent protection chip to the first charging chip, ChargerIC. Next to ChargerIC is a thermistor SY8809_NTC used to detect its temperature. The main control module BTSOC obtains the voltage of the thermistor SY8809_NTC. Based on the relationship between this voltage and temperature, ChargerIC can adjust the charging current. (ChargerIC controls the battery charging current by using its internal power transistors for pre-charging, trickle charging, constant current charging, and constant voltage charging. The charging current is regulated by a register, with a maximum charging current of 2.2A. The internal register controls the charging current magnitude.) A lower charging current results in a lower temperature for ChargerIC, which in turn lowers the battery temperature. This lower temperature detected by the battery thermistor allows the battery to be fully charged.

[0040] In another embodiment of the charging circuit provided in this application, the second charging module further includes a switching transistor connected between the second charging chip QiCharger and the first charging chip ChargerIC. The second charging chip QiCharger is used to connect to a second external power source, and the switching state of the second external power source supplying power to the battery is controlled by the on / off state of the switching transistor.

[0041] refer to Figure 2The second charging module also includes a switching transistor connected between the second charging chip QiCharger and the first charging chip ChargerIC. The second charging chip QiCharger can be a wireless charging chip of model CWR510W, the switching transistor can be a PMOS transistor of model GPK2009, and the second temperature sensor can be a thermistor CWR510W_NTC. In other words, the second charging module can be a charging module that uses wireless charging. The second charging chip QiCharger is used to connect to a second external power source. In this way, by controlling the on / off state of the switching transistor, the switching state of the second external power source supplying power to the battery can be controlled.

[0042] For example, an adapter or DC power supply is connected to the wireless power transmitter via a USB cable. The wireless power transmitter uses a power amplifier to transmit AC power through the TX inductor coil. Then, the wireless power receiver, i.e., the second charging chip QiCharger, receives the AC power through the RX inductor coil, which is strongly coupled to the TX coil. In the QiCharger section of the second charging chip, a rectifier converts the AC power to DC power, and the main LDO outputs the DC power, which is then output to the VIN pin of the first charging chip ChargerIC via a switching transistor. The first charging chip ChargerIC then charges the battery. Next to the second charging chip QiCharger is a thermistor CWR510W_NTC used to detect the temperature of the second charging chip QiCharger. The main control module BTSOC obtains the voltage of the thermistor CWR510W_NTC. Based on the correlation between this voltage value and temperature, the first charging chip ChargerIC can adjust the charging current. (The first charging chip ChargerIC regulates the charging current at the battery terminal. It can use the internal power transistor to pre-charge, trickle charge, constant current, and constant voltage charge the battery. The charging current is regulated by a register, with a maximum charging current of 2.2A. The internal register can control the magnitude of the charging current.) Thus, when the charging current is lower, the temperature of the first charging chip ChargerIC will decrease accordingly, the battery temperature will decrease accordingly, the temperature detected by the battery thermistor will be lower, and the battery will be fully charged.

[0043] In another embodiment of the charging circuit provided in this application, the second charging chip QiCharger includes a charging voltage node terminal, which is connected to the power connector and the control pin of the switching transistor respectively. When the power connector is not connected to the first external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a low level, the second charging chip QiCharger runs and the switching transistor is turned on.

[0044] In this embodiment, the second charging chip QiCharger includes a charging voltage node terminal, which is connected to both the power connector and the control pin of the switching transistor. In other words, the second charging chip QiCharger is connected to the power connector of the first charging module via the charging voltage node terminal. (Refer to...) Figure 2 The charging voltage node of the second charging chip QiCharger is the enable pin EN. The enable pin EN of the second charging chip QiCharger is connected to the VBUS_5V node of the power connector of the first charging module through the VBUS_5V node.

[0045] For example, when the power connector is not connected to the first external power source, since there is no DC power input at the VBUS_5V node of the power connector of the first charging module, the enable pin EN of the second charging chip QiCharger is at a low level. When the enable pin EN of the second charging chip QiCharger is at a low level, the second charging chip QiCharger starts to work. The gate of the PMOS transistor, which acts as a switch, is also at a low level. When the gate of the PMOS transistor is at a low level, the drain and source of the PMOS transistor are in a conducting state. Therefore, the DC power supply Qi_5V output by the second charging chip QiCharger is output to the VIN pin of the first charging chip ChargerIC after passing through the PMOS transistor to charge the battery.

[0046] In another embodiment of the charging circuit provided in this application, when the power connector is connected to the first external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a high level, the second charging chip QiCharger stops running and the switching transistor is turned off.

[0047] For example, when the power connector is connected to the first external power source, since the VBUS_5V node of the power connector of the first charging module has a DC power input, the enable pin EN of the second charging chip QiCharger is at a high level. When the enable pin EN of the second charging chip QiCharger is at a high level, the second charging chip QiCharger stops working, and the gate of the PMOS transistor, which acts as a switch, is also at a high level. When the gate of the PMOS transistor is at a high level, the drain and source of the PMOS transistor are in the cut-off state. Therefore, the second charging chip QiCharger cannot output DC power to the first charging chip ChargerIC.

[0048] In another embodiment of the charging circuit provided in this application, when the power connector is connected to the first external power supply and the second charging module is connected to the second external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a high level, the second charging chip QiCharger stops running and the switching transistor is turned off.

[0049] For example, when the power connector is connected to the first external power source and the second charging module is connected to the second external power source, that is, when the USB cable is plugged into the USB socket VBUS_5V for charging and the wireless charging device is also charging the wireless charging chip CWR510W, the VBUS_5V node of the power connector of the first charging module has DC power input. At this time, the enable pin EN of the second charging chip QiCharger is at a high level, the second charging chip QiCharger stops working, the gate of the PMOS transistor acting as a switch, that is, the control pin of the PMOS transistor is also at a high level, the drain and source of the PMOS transistor are in the cut-off state and do not conduct. Therefore, only the charging circuit of the first charging module works, that is, when the USB charging cable is plugged into the USB socket, the DC power output by the overvoltage and overcurrent protection chip is sent to the first charging chip ChargerIC, and the first charging chip ChargerIC charges the battery.

[0050] In another embodiment of the charging circuit provided in this application, the main control module BTSOC is connected to the first temperature sensor and the second temperature sensor through the first port respectively, so as to control the detection switch of the first temperature sensor and the second temperature sensor through the first port. The main control module BTSOC is also connected to the first temperature sensor through the second port to obtain the temperature of the first charging chip ChargerIC. The main control module BTSOC is also connected to the second temperature sensor through the third port to obtain the temperature of the second charging chip QiCharger.

[0051] refer to Figure 2The main control module BTSOC can be a Bluetooth chip of model ATS3089. Both the first and second temperature sensors are thermistors. The main control module BTSOC connects to the first and second temperature sensors respectively through a first port to control their detection switches. In other words, the main control module BTSOC can control the detection switches of the first and second temperature sensors by controlling the level of the first port. Additionally, the main control module BTSOC also connects to the first temperature sensor through a second port to obtain the temperature of the first charging chip ChargerIC. The main control module BTSOC also connects to the second temperature sensor through a third port to obtain the temperature of the second charging chip QiCharger. Here, the main control module BTSOC can connect between the first temperature sensor and the first voltage divider resistor R2 through the second port to obtain the voltage of the first temperature sensor through voltage division, and thus obtain the temperature of the first charging chip ChargerIC. Similarly, the main control module BTSOC can connect between the second temperature sensor and the second voltage divider resistor R1 through the third port to obtain the voltage of the second temperature sensor through voltage division, and thus obtain the temperature of the second charging chip QiCharger.

[0052] For example, the main control module BTSOC can output a voltage of 3.3V through the control pin GPIO31, which is connected in series with the thermistor SY8809_NTC to ground through the first voltage divider resistor R2, and then connected between the thermistor SY8809_NTC and the first voltage divider resistor R2 through the pin GPIO74 to obtain the voltage of the thermistor SY8809_NTC. Similarly, the main control module BTSOC can output a voltage of 3.3V through the control pin GPIO31, which is then connected in series with the thermistor CWR510W_NTC to ground through the second voltage divider resistor R1. The voltage of the thermistor CWR510W_NTC can then be obtained by connecting the thermistor CWR510W_NTC and the second voltage divider resistor R1 through the GPIO4 pin.

[0053] In another embodiment of the charging circuit provided in this application, a third temperature sensor is also included, which is disposed adjacent to the battery and is used to detect the temperature of the battery.

[0054] refer to Figure 2 The charging circuit also includes a third temperature sensor located near the battery. This third temperature sensor is a thermistor BAT_NTC. Whether the battery is charging or not, as long as the battery itself has power, the thermistor BAT_NTC is in working condition. In other words, as long as the battery itself has power, the third temperature sensor will continuously detect the battery temperature, thereby ensuring the safety of battery use.

[0055] In another embodiment of the charging circuit provided in this application, the first charging chip ChargerIC includes a PWM module and an NVDC module. The first charging chip ChargerIC is used to adjust the charging current to charge the battery through the PWM module and the NVDC module.

[0056] In this embodiment, the first charging chip, ChargerIC, integrates a complete PWM module and an NVDC module. The PWM and NVDC modules are used to regulate and control the charging current at the battery terminal, utilizing the chip's internal power transistors to perform pre-charging, trickle charging, constant current charging, and constant voltage charging of the battery. The charging current is regulated through a register, with a maximum charging current of 2.2A. The internal register can control the magnitude of the charging current.

[0057] In one embodiment, reference Figure 2 The main control module BTSOC can be a Bluetooth chip of model ATS3089. The main control module BTSOC also has multiple ports, including an ANT port for connecting the antenna BT_2G4, HOSCI and LOSCI ports for connecting the crystal oscillator, a GPIO port for connecting the Hall effect sensor of the charging case switch cover, a WIO0 port for connecting the power button, and a USB DP / DM port for the software programming channel connected to the power connector of the first charging module.

[0058] A second aspect of this application provides an earphone charging case, which includes any of the above-described charging circuits and an earphone charging interface connected to the charging circuit for charging the earphones.

[0059] refer to Figure 2 The earphone charging case provided in this application includes a charging circuit and an earphone charging interface connected to the charging circuit for charging the earphones, that is, the left and right earphone charging interfaces connected to the first charging chip ChargerIC of the charging circuit.

[0060] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

[0061] In the several embodiments provided in this application, it should be understood that the disclosed systems, instruments, and methods can be implemented in other ways. For example, the instrument embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between instruments or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0062] It should also be understood that the various implementation methods provided in this application can be combined arbitrarily to achieve different technical effects.

Claims

1. A charging circuit, characterized in that, include: The first charging module includes a first charging chip and a first temperature sensor disposed adjacent to each other. The first charging chip is connected to the battery to supply power to the battery, and the first temperature sensor is used to detect the temperature of the first charging chip. The second charging module includes a second charging chip and a second temperature sensor disposed adjacent to each other. The second charging chip is connected to the first charging chip to supply power to the battery through the first charging chip. The second temperature sensor is used to detect the temperature of the second charging chip. The main control module is connected to the first charging chip, the first temperature sensor, and the second temperature sensor, respectively, and is used to control the charging speed of the first charging chip according to the temperature of the first charging chip, and to control the charging speed of the first charging chip according to the temperature of the second charging chip.

2. The charging circuit according to claim 1, characterized in that, The first charging module further includes a power connector for connecting to a first external power source and a charging protection chip, wherein the charging protection chip is connected to the power connector and the first charging chip respectively.

3. The charging circuit according to claim 2, characterized in that, The second charging module further includes a switching transistor connected between the second charging chip and the first charging chip. The second charging chip is used to connect to a second external power source, and the switching state of the second external power source supplying power to the battery is controlled by the on / off state of the switching transistor.

4. The charging circuit according to claim 3, characterized in that, The second charging chip includes a charging voltage node terminal, which is connected to the power connector and the control pin of the switching transistor respectively. When the power connector is not connected to the first external power supply, the charging voltage node terminal and the control pin of the switching transistor are at a low level, the second charging chip is running and the switching transistor is turned on.

5. The charging circuit according to claim 4, characterized in that, When the power connector is connected to the first external power source, the charging voltage node and the control pin of the switching transistor are at a high level, the second charging chip stops operating and the switching transistor is turned off.

6. The charging circuit according to claim 4, characterized in that, When the power connector is connected to the first external power source and the second charging module is connected to the second external power source, the charging voltage node and the control pin of the switching transistor are at a high level, the second charging chip stops operating and the switching transistor is turned off.

7. The charging circuit according to claim 1, characterized in that, The main control module is connected to the first temperature sensor and the second temperature sensor respectively through the first port, so as to control the detection switch of the first temperature sensor and the second temperature sensor through the first port. The main control module is also connected to the first temperature sensor through the second port to obtain the temperature of the first charging chip. The main control module is also connected to the second temperature sensor through the third port to obtain the temperature of the second charging chip.

8. The charging circuit according to claim 1, characterized in that, It also includes a third temperature sensor disposed adjacent to the battery, the third temperature sensor being used to detect the temperature of the battery.

9. The charging circuit according to claim 1, characterized in that, The first charging chip includes a PWM module and an NVDC module, and the first charging chip is used to adjust the charging current to charge the battery through the PWM module and the NVDC module.

10. An earphone charging case, characterized in that, It includes a charging circuit as described in any one of claims 1 to 9, and an earphone charging interface connected to the charging circuit for charging the earphones.

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