Power management circuit, earphone charging box and wireless earphone system

Abstract

The present invention provides a power management circuit, an earphone charging case, and a wireless earphone system. The power management circuit includes: a battery; a charging and boosting circuit having a charging input terminal, a battery charging terminal connected to the battery, a voltage output terminal, and an inductor. The circuit has a charging mode and a boosting power supply mode. When the charging and boosting circuit is in the charging mode, the circuit is configured to control charging of the battery using an external power source through the battery charging terminal based on the inductor. When the charging and boosting circuit is in the boosting power supply mode, the circuit is configured to boost the battery voltage based on the inductor and output the voltage through the voltage output terminal to supply power externally. The inductor is in either the charging mode or the boosting power supply mode at the same time.

Description

Technical field

[0001] The present invention relates to the field of power management, and in particular to a power management circuit, an earphone charging box, and a wireless earphone system. [Background Technology]

[0002] like Figure 1 As shown in the figure, the conventional TWS (True Wireless Stereo) headphone charging circuit consists of two parts: the first circuit 10 is located in the charging box, which includes a second charger and a boost circuit; the second circuit 20 is located in the wireless headphones. The linear charger in the charging box charges the battery BAT2 in the charging box. The boost circuit boosts the voltage of battery BAT2 to a predetermined voltage, such as 5V, meaning that the voltage of VCHG is 5V. The first charger in the wireless headphones charges the headphone battery VBAT1 via the 5V voltage. In traditional designs, the second charger is typically a linear charging circuit, which has the disadvantages of slow charging speed and high heat generation. One improvement is to replace it with a switching charging circuit, but a switching charging circuit requires an additional inductor, which increases the cost significantly, and the inductor takes up a lot of space. [Summary of the invention]

[0003] One of the purposes of the present invention is to provide a power management circuit with fast charging speed, low heat generation, low cost and small space occupation.

[0004] A second object of the present invention is to provide an earphone charging box that uses a power management circuit with fast charging speed, low heat generation, low cost and small space occupation.

[0005] A third object of the present invention is to provide a wireless headset system, wherein the headset charging box adopts a power management circuit with fast charging speed, low heat generation, low cost and small space occupation.

[0006] According to one aspect of the present invention, the present invention provides a charging management circuit, comprising: a battery; a charging and boosting circuit, comprising a charging input terminal, a battery charging terminal connected to the battery, a voltage output terminal, and an inductor, and having a charging mode and a boosting power supply mode. When the charging and boosting circuit is in the charging mode, the charging and boosting circuit is configured to control the charging of the battery using an external power supply through the battery charging terminal based on the inductor. When the charging and boosting circuit is in the boosting power supply mode, the charging and boosting circuit is configured to boost the voltage of the battery based on the inductor and then output the voltage through the voltage output terminal to supply power to the outside. The inductor is in one of the charging mode and the boosting power supply mode at the same time.

[0007] According to another aspect of the present invention, the present invention provides an earphone charging box, which includes: a box body and a power management circuit disposed in the box body, wherein the box body is provided with an earphone compartment capable of accommodating wireless earphones. The charging management circuit includes: a battery; a charging and boosting circuit, which has a charging input terminal, a battery charging terminal coupled to the battery, a voltage output terminal, and an inductor, and has a charging mode and a boost power supply mode. When the charging and boosting circuit is in the charging mode, the charging and boosting circuit is configured to control the charging of the battery through the battery charging terminal using an external power supply based on the inductor. When the charging and boosting circuit is in the boost power supply mode, the charging and boosting circuit is configured to boost the voltage of the battery based on the inductor and output the voltage through the voltage output terminal to supply power to the outside. The inductor is in one of the charging mode and the boost power supply mode at the same time.

[0008] According to another aspect of the present invention, a wireless headset system is provided, comprising: the headset charging case described above; and wireless headsets capable of being placed in a headset compartment of the headset charging case. When the wireless headsets are placed in the headset compartment, the voltage output terminal of the power management circuit is electrically coupled to the charging input terminal of the wireless headsets.

[0009] Compared with the existing technology, the charging and boost circuit in the present invention has a charging mode and a boost power supply mode. It works based on the same inductor in different modes. Only one inductor can support the charging mode and the boost power supply mode. Since it adopts an inductor-based switching charging scheme, it has a fast charging speed and low heat generation. Since no inductor is added, the cost is relatively low and the space occupied is small.

[0010] The present invention can achieve more specific and beneficial effects which will be described in detail below with reference to specific embodiments.

Brief Description of the Drawings

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0012] Figure 1 A circuit diagram of a wireless headset system in the prior art

[0013] Figure 2 is a circuit diagram of a wireless headset system in one embodiment of the present invention;

[0014] Figure 3 for Figure 2 A circuit diagram of a charging and boosting circuit in one embodiment;

[0015] Figure 4 for Figure 3 The inductor current waveform of the charging and boost circuit in the charging mode;

[0016] Figure 5 for Figure 3 The inductor current waveform of the charging and boost circuit in the boost power supply mode;

[0017] Figure 6 for Figure 3 The inductor current waveform of the charging and boost circuit in the alternating mode of charging mode and boost power supply mode;

[0018] Figure 7 for Figure 3 A circuit diagram of a voltage selection circuit of a charging and boosting circuit in one embodiment;

[0019] Figure 8 for Figure 3 A circuit diagram of a hybrid control unit of a charging and boosting circuit in one embodiment. [Specific implementation method]

[0020] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless there is a conflict.

[0021] Figure 2 FIG. 1 is a circuit diagram of the wireless headset system in the first embodiment of the present invention. Figure 2 As shown, the wireless headset system includes a headset charging box and a wireless headset 200. The headset charging box includes a box body and a power management circuit 100 disposed in the box body. The box body includes a box cover. The box body is provided with a headset compartment. After the box cover is opened, the wireless headset 200 can be placed in the headset compartment or taken out of the headset compartment. The wireless headset is a true wireless stereo (TWS) headset, which can communicate with a smart terminal, such as a smartphone, tablet computer, etc., via Bluetooth to answer calls or listen to music.

[0022] like Figure 2As shown, the power management circuit 100 includes a charging and boosting circuit 110, a battery BAT2, and a charger 130. The charging and boosting circuit 110 has a charging input terminal VIN, a battery charging terminal VBAT2 coupled to the battery BAT2, and a voltage output terminal VO1.

[0023] The wireless headset 200 includes a headset charger 210 coupled to a charging input terminal VCHG1 and a headset battery BAT1. The headset charger 210 charges the headset battery BAT1 based on the voltage input from the charging input terminal. When the wireless headset 200 is placed in the charging compartment of the headset charging case, the charging input terminal VCHG of the wireless headset is coupled to the voltage output terminal VO1 of the power management circuit 100, and the ground input terminal of the wireless headset is coupled to the ground output terminal of the charging management circuit 100. The wireless headset 200 also includes an analog-to-digital conversion module 220, a radio frequency module 230, and a settings module 240.

[0024] The charging and boosting circuit 110 includes an inductor and has a charging mode and a boosting power supply mode. When in the charging mode, the charging and boosting circuit 110 is configured to charge the battery BAT2 via the battery charging terminal VBAT2 using an external power source introduced from the charging input terminal VIN based on the inductor. When in the boosting power supply mode, the charging and boosting circuit 110 is configured to boost the voltage of the battery BAT2 based on the inductor and output the voltage via the voltage output terminal VO1 for external power supply. When the inductor is in either the charging mode or the boosting power supply mode at the same time, in the charging mode, the inductor is used as the energy storage element of the charging and boosting circuit 110 for energy transfer. In the charging mode, the same inductor is used as the energy storage element of the charging and boosting circuit 110 for energy transfer. This eliminates the need for two inductors as in the prior art, reducing cost and footprint. In addition, since inductance is used for energy transfer in charging mode, it has higher energy efficiency, faster charging speed and less heat generation than existing linear chargers.

[0025] In one embodiment, when the voltage at the charging input terminal VIN is higher than a first predetermined threshold VR1 and the voltage at the battery charging terminal VBAT2 is lower than a second predetermined threshold VR2, the charging and boosting circuit 110 is in a charging mode. When the voltage at the charging input terminal VIN is lower than the first predetermined threshold VR1 and the voltage at the battery charging terminal VBAT2 is higher than a second predetermined threshold VR2, the charging and boosting circuit 110 is in a boost power supply mode. When the voltage at the charging input terminal VIN is higher than the first predetermined threshold VR1 and the voltage at the battery charging terminal VBAT2 is higher than a second predetermined threshold VR2, the charging and boosting circuit 110 operates in an alternating mode between a boost power supply mode and a charging mode. In the alternating mode, the circuit operates in the boost power supply mode for a period of time, then in the charging mode for a period of time, and then returns to the boost power supply mode, and so on. The first predetermined threshold VR1 is higher than the second predetermined threshold VR2. A voltage at the charging input terminal VIN exceeding a first predetermined threshold VR1 indicates that the charging input terminal VIN is connected to an external power source. A voltage at the charging input terminal VIN below the first predetermined threshold VR1 indicates that the charging input terminal VIN is not connected to an external power source. A voltage at the battery charging terminal VBAT2 exceeding a second predetermined threshold VR2 indicates that the battery BAT2 still has sufficient energy to supply power. A voltage at the battery charging terminal VBAT2 below the second predetermined threshold VR2 indicates that the battery BAT2 does not have sufficient energy to supply power. For example, the first predetermined threshold VR1 may be 4.5V, and the second predetermined threshold VR2 may be 3.2V. Figure 3 for Figure 2 FIG. 1 is a circuit diagram of the charging and boosting circuit 110 in one embodiment. Figure 3 As shown, the charging and boosting circuit 110 further includes a hybrid control unit 111, an output capacitor C1, and multiple switching devices. The hybrid control unit 111 is used to control the conduction and cutoff of the multiple switching devices, using the inductor L1 as an energy storage element to transfer energy, thereby controlling the charging of the battery in the charging mode and outputting a voltage through the voltage output terminal in the boosting power supply mode. The output capacitor C1 is used to stabilize the voltage output by the voltage output terminal.

[0026] like Figure 3As shown, in one embodiment, the switching device includes a first switch S1, a second switch S2, and a third switch S3. The inductor L1 is coupled between the intermediate node LX and the battery charging terminal VBAT2, the first switch S1 is coupled between the charging input terminal VIN and the intermediate node LX, the second switch S2 is coupled between the intermediate node LX and the ground terminal, the third switch S3 is coupled between the intermediate node LX and the voltage output terminal VO1, the output capacitor C1 is coupled between the voltage output terminal VO1 and the ground terminal, the first input terminal of the hybrid control unit 111 is coupled to the voltage output terminal VO1, the second input terminal of the hybrid control unit 111 is coupled to the intermediate node LX, and the three output terminals GS1, GS2, and GS3 of the hybrid control unit 111 are coupled to the control terminals of the first switch S1, the second switch S2, and the third switch S3, respectively. When the charging and boosting circuit 110 is in the charging mode, the hybrid control unit 111 controls the third switch S3 to be continuously off, obtains the charging current based on the voltage of the intermediate node LX, and controls the first switch S1 and the second switch S2 to be alternately turned on according to the charging current or the output voltage of the voltage output terminal VO1 to achieve constant voltage or constant current charging. Specifically, the hybrid control unit 111 controls the duty cycle of the first switch S1 (the ratio of the on-time of the first switch in a cycle to the cycle) to make the charging voltage output by the voltage output terminal VO1 equal to a first predetermined reference voltage value to achieve constant voltage charging, or to make the charging current output by the voltage output terminal VO1 equal to a predetermined reference current value to achieve constant current charging. When the charging and boosting circuit 110 is in the boosting power supply mode, the hybrid control unit 111 controls the first switch S1 to be continuously turned off, and controls the second switch S2 and the third switch S3 to be alternately turned on according to the output voltage of the voltage output terminal VO1 and a second predetermined reference voltage value to obtain a boosted predetermined output voltage according to the voltage of the battery BAT2. At this time, the predetermined output voltage can power the charging input terminal VCHG of the wireless headset 200.

[0027] like Figure 3 As shown, the charging and boosting circuit 110 further includes a voltage selection circuit 112. The voltage selection circuit 112 selects the highest voltage among the voltage at the charging input terminal VIN, the voltage at the battery charging terminal VBAT2, and the voltage at the voltage output terminal VO1, and outputs the highest voltage as the power supply voltage for the hybrid control unit 111. This ensures normal on / off control of the switches S1, S2, and S3.

[0028] Figure 4 for Figure 3 The inductor current waveform of the charging and boost circuit in the charging mode. Figure 4As shown, the inductor current flowing from the intermediate node LX to the battery charging terminal VBAT2 is defined as a positive value, that is, Figure 3 From right to left, the positive value is Figure 4 The inductor current is always greater than or equal to zero. During the T1 period, the hybrid control unit MixCTRL controls the first switch S1 to turn on. At this time, the second switch S2 and the third switch S3 are both disconnected. The current flows from the charging input terminal VIN through the first switch S1 and the inductor L1 to the battery charging terminal VBAT2. The current of the inductor L1 increases at a slope of (VIN-VBAT2) / L. During this period, energy is stored in the inductor. Among them, VIN is the voltage value of the charging input terminal VIN, VBAT2 is the voltage value of the battery charging terminal VBAT2 node (that is, the voltage value of the battery BAT2), and L is the inductance value of the inductor L1. During the T2 period, the hybrid control unit MixCTRL controls the second switch S2 to turn on. At this time, the first switch S1 and the third switch S3 are both disconnected. The current flows from the ground through the second switch S2 and the inductor L1 to the battery charging terminal VBAT2 (reference Figure 3 ), the current of inductor L1 decreases at a slope of (-VBAT2) / L (energy is released to the inductor during this period).

[0029] Figure 5 for Figure 3 The inductor current waveform of the charging and boost circuit in the boost power supply mode. Figure 5 As shown in the figure, the inductor current flowing from the middle node LX to VBAT2 is defined as a positive value, that is, Figure 3 The flow from right to left is positive. Figure 5 The inductor current is always less than or equal to zero. Figure 5 The dotted line in the figure represents the zero current reference line, which is 0 amperes. During the T1 period, the hybrid control unit MixCTRL controls the switch S2 to turn on (at this time, S1 and S3 are both open), and the current flows from VBAT2 through L1 and S2 to the ground (reference Figure 3 ), the current of inductor L1 decreases at a slope of -VBAT2 / L (during this period, the inductor stores energy, the absolute value of the inductor current increases, and therefore the inductor energy storage increases). During T2, the hybrid control unit MixCTRL controls switch S3 to turn on (at this time, both S1 and S2 are open), and the current flows from VBAT2 through L1 and S3 to VO1 (reference Figure 3 ), the current of inductor L1 increases at a slope of (VO1-VBAT2) / L (energy is released to the inductor during this period, the absolute value of the inductor current decreases, and therefore the energy stored in the inductor decreases), where VO1 is the voltage value of the voltage output terminal VO1.

[0030] Figure 6 for Figure 3 The inductor current waveform of the charging and boost circuit in the alternating mode of charging mode and boost power supply mode. Figure 6As shown, (the inductor current flowing from SW to VBAT2 is defined as a positive value, that is, Figure 3 The flow from right to left is positive. Figure 6 The inductor current is sometimes positive and sometimes negative. The dotted line is the zero current reference line. The part above this line is positive, and the part below this line is negative. During the T1 period, the hybrid control unit MixCTRL controls the switch S1 to turn on (at this time, S2 and S3 are both open), and the current flows from VIN through S1 and L1 to VBAT2 (reference Figure 3 ), the current of inductor L1 increases at the slope of (VIN-VBAT2) / L (energy is stored in the inductor during this period). During T2, the hybrid control unit MixCTRL controls switch S2 to turn on (at this time, S1 and S3 are both open), and the current flows from ground through S2 and L1 to VBAT2 (reference Figure 3 ), the current in inductor L1 decreases at a slope of (-VBAT2) / L (energy is released to the inductor during this period). During T3, the hybrid control unit MixCTRL continues to control switch S2 to turn on (at this time, S1 and S3 are both open), and the current flows from VBAT2 through L1 and S2 to ground (reference Figure 3 ), the current of inductor L1 decreases at a slope of -VBAT2 / L (during this period, the inductor stores energy, the absolute value of the inductor current increases, and therefore the inductor energy storage increases). During T4, the hybrid control unit MixCTRL controls switch S3 to turn on (at this time, S1 and S2 are both open), and the current flows from VBAT2 through L1 and S3 to VO1 (reference Figure 3 ), the current of inductor L1 increases at a slope of (VO1-VBAT2) / L (energy is released to the inductor during this period, the absolute value of the inductor current decreases, and therefore the energy stored in the inductor decreases), where VO1 is the voltage value of the VO1 node, VBAT2 is the voltage value of the VBAT2 node (that is, the voltage value of the battery BAT2), and L is the inductance value of the inductor L1.

[0031] Figure 7 for Figure 3A circuit diagram of the voltage selection circuit 112 of the charging and boosting circuit 110 in one embodiment. The voltage selection circuit 112 includes a third comparator com3, a first selection circuit 1121, a fourth comparator com4, and a second selection circuit 1122. The third comparator com3 compares the voltage at the charging input terminal VIN, the voltage at the battery charging terminal VBAT2, and the voltage at the voltage output terminal VO1. The first selection circuit 1121 selects the larger of the two voltages based on the comparison result of the third comparator com3. The fourth comparator com4 compares the voltage selected by the first selection circuit 1121 with the remaining voltage among the voltage at the charging input terminal VIN, the voltage at the battery charging terminal VBAT2, and the voltage output terminal VO1. The second selection circuit 1122 selects the larger of the two voltages based on the comparison result of the fourth comparator com4.

[0032] Specifically, the first selection circuit 1121 includes a first inverter INV1, a first selection switch K1 coupled between the charging input terminal VIN and the temporary comparison terminal Vm, and a second selection switch K2 coupled between the battery charging terminal VBAT2 and the temporary comparison terminal Vm. The inverting input terminal of the third comparator com2 is coupled to the charging input terminal VIN, the non-inverting input terminal of the third comparator com2 is coupled to the battery charging terminal VBAT2, the output terminal of the third comparator com2 is coupled to the control terminal of the second selection switch K2, and the output terminal of the third comparator is coupled to the first selection switch K1 after passing through the first inverter INV1. Thus, when the voltage at the charging input terminal VIN is higher than the voltage at the battery charging terminal VBAT2, the first selection switch K1 is turned on and the second selection switch K2 is turned off, selecting the higher voltage. When the voltage at the charging input terminal VIN is lower than the voltage at the battery charging terminal VBAT2, the first selection switch K1 is turned off and the second selection switch K2 is turned on, selecting the higher voltage. The second selection circuit 1122 includes a second inverter INV2, a third selection switch K3 coupled between the provisional comparison terminal Vm and the final output terminal VX, and a fourth selection switch K4 coupled between the voltage output terminal VO1 and the final output terminal VX. The inverting input of the fourth comparator com4 is coupled to the provisional comparison terminal Vm, the non-inverting input of the fourth comparator com4 is coupled to the voltage output terminal VO1, the output of the fourth comparator com4 is coupled to the control terminal of the fourth selection switch K4, and the output of the fourth comparator com4 is coupled to the third selection switch K3 after passing through a second inverter. Thus, when the voltage at the voltage output terminal VO1 is higher than the voltage at the provisional comparison terminal Vm, the fourth selection switch K4 is turned on and the third selection switch K3 is turned off, selecting the higher voltage. When the voltage at the voltage output terminal VO1 is lower than the voltage at the provisional comparison terminal Vm, the fourth selection switch K4 is turned off and the third selection switch K3 is turned on, selecting the higher voltage.

[0033] Figure 8 for Figure 3 A circuit diagram of the hybrid control unit 111 of the charging and boosting circuit in one embodiment. Figure 8 As shown, the hybrid control unit 111 includes a first comparator Com1 , a second comparator Com2 , and a mode control unit 1111 .

[0034] The first comparator Com1 compares the voltage of the charging input terminal VIN with a first predetermined threshold value VR1, and the second comparator Com1 compares the voltage of the battery charging terminal VBAT2 with a second predetermined threshold value VR2. The mode control unit 1111 selects one of the charging mode, the boost power supply mode, and the alternating mode of the boost power supply mode and the charging mode according to the results of the first comparator Com1 and the second comparator Com2. The three output terminals of the mode control unit 1111 are respectively coupled to the control terminals of the first switch S1, the second switch S2, and the third switch S3. The first input terminal of the mode control unit 1111 is coupled to the voltage output terminal VO1, and the second input terminal of the mode control unit 1111 is coupled to the intermediate node LX.

[0035] In the present invention, words such as "coupled", "connected", "connected", "connected", "connected", etc. that indicate electrical connection, unless otherwise specified, include both direct connections between two or more circuit objects without any intervening circuit objects and indirect connections between two or more circuit objects through one or more intervening circuit objects. For example, two circuit objects that are directly connected to each other are said to be "coupled / connected" to each other. Similarly, two circuit objects with one or more intervening circuit objects connected therebetween are also said to be "coupled / connected" to each other. In other words, "coupled", "connected", etc. can refer to direct electrical connections or indirect electrical connections. Indirect electrical connections refer to connections with other components in between, such as resistors, capacitors, etc.

[0036] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

Claims

1. A power management circuit, characterized in that: It includes: Battery; A charging and boosting circuit having a charging input terminal, a battery charging terminal connected to the battery, a voltage output terminal, and an inductor. The circuit has a charging mode and a boosting power supply mode. When the charging and boosting circuit is in the charging mode, the charging and boosting circuit is configured to control charging of the battery using an external power supply through the battery charging terminal based on the inductor. When the charging and boosting circuit is in the boosting power supply mode, the charging and boosting circuit is configured to boost the voltage of the battery based on the inductor and then output the voltage through the voltage output terminal to supply power to the outside. The inductor is in one of the charging mode and the boosting power supply mode at the same time. The charging and boosting circuit further includes a hybrid control unit, an output capacitor and a plurality of switching devices; The hybrid control unit is used to control the on and off of the multiple switching devices, using the inductor as an energy storage element to carry out energy transfer, so as to achieve charging control of the battery in the charging mode, and output voltage through the voltage output terminal in the boost power supply mode; The output capacitor is used to stabilize the voltage output by the voltage output terminal. The plurality of switch devices include a first switch, a second switch, and a third switch, The inductor is connected between the intermediate node and the battery charging terminal, the first switch is connected between the charging input terminal and the intermediate node, the second switch is connected between the intermediate node and the ground terminal, the third switch is connected between the intermediate node and the voltage output terminal, and the output capacitor is connected between the voltage output terminal and the ground terminal. The first input terminal of the hybrid control unit is coupled to the voltage output terminal, the second input terminal of the hybrid control unit is coupled to the intermediate node, and the three output terminals of the hybrid control unit are respectively connected to the control terminals of the first switch, the second switch, and the third switch. When the charging and boost circuit is in the charging mode, the hybrid control unit controls the third switch to be continuously turned off, obtains the charging current based on the voltage of the intermediate node, and controls the first switch and the second switch to be alternately turned on according to the charging current or the output voltage of the voltage output terminal to achieve constant voltage or constant current charging. When the charging and boosting circuit is in the boosting power supply mode, the hybrid control unit controls the first switch to be continuously turned off, and controls the second switch and the third switch to be alternately turned on according to the output voltage of the voltage output terminal and the reference voltage value to obtain a predetermined output voltage after boosting according to the battery voltage. The hybrid control unit includes a first comparator, a second comparator, and a mode control unit. The first comparator compares the voltage of the charging input terminal with a first predetermined threshold value, the second comparator compares the voltage of the battery charging terminal with a second predetermined threshold value, and the mode control unit selects one of the charging mode, the boost power supply mode, and the alternating mode of the boost power supply mode and the charging mode according to the results of the first comparator and the second comparator. The three output terminals of the mode control unit are respectively connected to the control terminals of the first switch, the second switch and the third switch, the first input terminal of the mode control unit is coupled to the voltage output terminal, and the second input terminal of the mode control unit is coupled to the intermediate node.

2. The power management circuit according to claim 1, wherein: When the voltage at the charging input terminal is higher than a first predetermined threshold and the voltage at the battery charging terminal is lower than a second predetermined threshold, the charging and boosting circuit is in a charging mode; When the voltage at the charging input terminal is lower than a first predetermined threshold and the voltage at the battery charging terminal is higher than a second predetermined threshold, the charging and boosting circuit is in a boost power supply mode; When the voltage of the charging input terminal is higher than a first predetermined threshold and the voltage of the battery charging terminal is higher than a second predetermined threshold, the charging and boosting circuit operates in an alternating mode of boosting power supply mode and charging mode.

3. The power management circuit according to claim 1, wherein: The charging and boosting circuit further includes: a voltage selection circuit which selects the highest voltage among the voltage of the charging input terminal, the voltage of the battery charging terminal and the voltage of the voltage output terminal and outputs it as the power supply voltage of the hybrid control unit.

4. The power management circuit according to claim 3, wherein: The voltage selection circuit includes a third comparator, a first gating circuit, a fourth comparator and a second gating circuit, The third comparator compares the voltage of the charging input terminal, the voltage of the battery charging terminal, and the voltage of the voltage output terminal. The first selection circuit selects the larger of the two voltages according to the comparison result of the third comparator. The fourth comparator compares the voltage selected by the first selection circuit with the remaining voltage among the voltage of the charging input terminal, the voltage of the battery charging terminal, and the voltage of the voltage output terminal, and the second selection circuit selects the larger of the two voltages according to the comparison result of the fourth comparator.

5. The power management circuit according to claim 4, wherein: The first selection circuit includes a first inverter, a first selection switch K1 connected between the charging input terminal and the temporary comparison terminal, and a second selection switch K2 connected between the battery charging terminal and the temporary comparison terminal. The inverting input terminal of the third comparator is coupled to the charging input terminal, the non-inverting input terminal of the third comparator is coupled to the battery charging terminal, the output terminal of the third comparator is connected to the control terminal of the second selection switch K2, and the output terminal of the third comparator is connected to the first selection switch K1 after passing through the first inverter. The second gating circuit includes a second inverter, a third selection switch K3 connected between the temporary comparison terminal and the final output terminal VX, and a fourth selection switch K4 connected between the voltage output terminal and the final output terminal VX. The inverting input terminal of the fourth comparator is coupled to the temporary comparison terminal, the non-inverting input terminal of the fourth comparator is coupled to the voltage output terminal, the output terminal of the fourth comparator is connected to the control terminal of the fourth selection switch K4, and the output terminal of the fourth comparator is connected to the third selection switch K3 after passing through the second inverter.

6. An earphone charging box, characterized in that: It includes: It includes a box body and a power management circuit as described in any one of claims 1 to 5 arranged in the box body, and an earphone compartment capable of accommodating wireless earphones is provided in the box body.

7. A wireless headset system, characterized in that: It includes: The earphone charging box according to claim 6; Wireless earphones can be placed in the earphone compartment of the earphone charging box. When the wireless headset is placed in the headset compartment, the voltage output end of the power management circuit is electrically coupled to the charging input end of the wireless headset.

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