Earphone charging system and charging method thereof

Abstract

The present application provides an earphone charging system and a charging method thereof. The earphone charging system includes an earphone device and a charging device. The earphone device or the charging device adjusts a charging current to switch between a first current and a second current to perform data transmission between the earphone device and the charging device.

Description

Technical Field

[0001] This invention relates to a charging device, and more particularly to an earphone charging system and charging method thereof. Background Technology

[0002] Generally, wireless earbuds have a battery to power their operation. Additionally, wireless earbuds usually come with a dedicated charging case. The charging case houses the earbuds and provides AC voltage; therefore, the earbuds need a rectifier circuit to convert the AC voltage to DC voltage to charge the battery. Furthermore, the charging case allows for one-way communication between the earbuds and the charging case. Summary of the Invention

[0003] This invention provides an earphone charging system and charging method, which enables bidirectional communication between the charging device and the earphone device.

[0004] The headphone charging system of the present invention includes a headphone device and a charging device. The headphone device includes a headphone battery and a charging circuit. The charging circuit is coupled to the signal input terminal of the headphone battery and the headphone device. The charging device is used to accommodate and couple to the headphone device and provide charging current. The charging circuit charges the headphone battery according to the charging current, and the charging device or the headphone device adjusts the charging current to switch between a first current and a second current to perform data transmission between the headphone device and the charging device.

[0005] In one embodiment of the present invention, the aforementioned headphone device includes a control circuit coupled to a charging circuit, which controls the charging circuit to adjust the charging current to switch between a first current and a second current. A sensing circuit coupled to the control circuit and the signal input terminal of the headphone device senses the charging current to generate a sensing signal, and the control circuit determines the data transmitted by the charging device based on the sensing signal.

[0006] In one embodiment of the present invention, the charging circuit has a charging current setting pin, and the earphone device includes an impedance circuit coupled to the control circuit and the charging current setting pin. The impedance circuit is controlled by the control circuit to change its impedance, and the charging circuit adjusts the charging current between a first current and a second current in response to the impedance change of the impedance circuit.

[0007] In one embodiment of the present invention, the impedance circuit includes a transistor, the collector and emitter of which are respectively coupled to a charging current setting pin and a ground voltage, and the base of the transistor is coupled to a control circuit. A resistor is coupled between the base and emitter of the transistor, and the control circuit controls the conduction state of the transistor to adjust the impedance of the impedance circuit.

[0008] In one embodiment of the present invention, the sensing circuit includes a capacitor and a transistor. One end of the capacitor is coupled to the signal input terminal of the headphone device. The base of the transistor is coupled to the other end of the capacitor, and the collector and emitter of the transistor are coupled to the operating voltage and the ground voltage, respectively. The collector of the transistor is also coupled to the control circuit, and the sensing signal is generated at the collector of the transistor.

[0009] In one embodiment of the present invention, the charging device includes a rechargeable battery, a DC-DC conversion circuit, a control circuit, a current adjustment circuit, and a sensing circuit. The rechargeable battery provides a DC voltage. The DC-DC conversion circuit is coupled to the rechargeable battery and converts the DC voltage into an output voltage. The control circuit is coupled to the DC-DC conversion circuit. The current adjustment circuit is coupled to the control circuit, the DC-DC conversion circuit, and the signal output terminal of the charging device. It generates a charging current based on the output voltage and is controlled by the control circuit to adjust the charging current to transmit data provided by the control circuit. The sensing circuit is coupled to the control circuit and the signal output terminal of the charging device, senses the charging current, and generates a sensing signal. The control circuit determines the data transmitted by the headphone device based on the sensing signal.

[0010] In one embodiment of the present invention, the current adjustment circuit includes a transistor and a resistor. The emitter and collector of the transistor are respectively coupled to the signal output terminals of the DC-DC conversion circuit and the charging device, and the base of the transistor is coupled to a control circuit. The resistor is coupled between the emitter and base of the transistor, and the control circuit controls the conduction state of the transistor to adjust the charging current.

[0011] In one embodiment of the present invention, the control circuit controls the current adjustment circuit to adjust the current value of the charging current, and determines whether the headphone device can receive the data transmitted by the charging device based on the sensing signal.

[0012] The present invention also provides a charging method for an earphone charging system. The earphone charging system includes an earphone device and a charging device. The charging method includes the following steps: providing a charging current through the charging device; charging the earphone battery of the earphone device through the charging circuit of the earphone device according to the charging current; controlling the earphone device or the charging device to adjust the charging current between a first current and a second current to perform data transmission between the earphone device and the charging device.

[0013] In one embodiment of the present invention, the above-mentioned headphone device includes an impedance circuit coupled to a charging current setting pin of the charging circuit, and the charging method of the headphone charging system includes adjusting the impedance of the impedance circuit so that the charging circuit adjusts the charging current between a first current and a second current in response to the impedance change of the impedance circuit.

[0014] In one embodiment of the present invention, the charging method of the above-described headphone charging system includes the following steps: adjusting the current value of the charging current; sensing the charging current to generate a sensing signal; and determining, based on the sensing signal, whether the headphone device can receive data transmitted by the charging device.

[0015] Based on the above, the headphone device or charging device of the present invention can adjust the charging current of the charging device to charge the headphone battery to switch between a first current and a second current, so as to transmit data between the headphone device and the charging device, thereby realizing bidirectional communication between the charging device and the headphone device.

[0016] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an earphone charging system according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of an earphone charging system according to another embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of an earphone charging system according to another embodiment of the present invention.

[0020] Figure 4 This is a flowchart of a charging method for an earphone charging system according to an embodiment of the present invention. Detailed Implementation

[0021] To make the contents of this invention more readily apparent, the following specific embodiments are provided as examples on which this invention can indeed be implemented. Furthermore, wherever possible, components / members referred to by the same reference numerals in the drawings and embodiments represent the same or similar parts.

[0022] Figure 1 This is a schematic diagram of an earphone charging system according to an embodiment of the present invention. Please refer to it. Figure 1 The headphone charging system includes a charging device 102 and a headphone device 104. The charging device 102 accommodates and couples to the headphone device 104. The headphone device 104 may include a charging circuit 106 and a headphone battery 108. The charging circuit 106 is coupled to the signal input terminal of the headphone device 104 and the headphone battery 108. The headphone battery 108 may be, for example, a lithium-ion (Li-Ion) battery, a lithium polymer (Li-polymer) battery, or a nickel-metal hydride (NiMH) battery, but is not limited thereto. Furthermore, the charging circuit 106 may be implemented, for example, using a Texas Instruments BQ25173 chip, but is not limited thereto.

[0023] The charging device 102 can provide a DC charging current IC1 to the headphone device 104 via a power transmission line or a POGO pin, but is not limited thereto. The charging circuit 106 of the headphone device 104 can charge the headphone battery 108 according to the charging current IC1. The charging device 102 can switch between a first current and a second current (e.g., between 50mA and 60mA, but is not limited thereto) by adjusting the charging current IC1 to transmit data signals to the headphone device 104. Similarly, the headphone device 104 can also switch between a first current and a second current by adjusting the charging current IC1 to transmit data signals to the charging device 102. During the period when the charging device 102 or the headphone device 104 is transmitting data signals, the charging current IC1 provided by the charging device 102 can still charge the headphone battery 108.

[0024] Thus, the charging device 102 provides a DC charging current IC1 to the headphone device 104. During data transmission, the charging device 102 or the headphone device 104 adjusts the charging current IC1 to switch between a first current and a second current, enabling bidirectional communication between the charging device 102 and the headphone device 104. The data transmitted between the charging device 102 and the headphone device 104 may include, for example, the headphone device 104's battery level, pairing status instructions, acknowledgment (ACK) signals, negative acknowledgment (NACK) signals, standby mode instructions, sleep mode instructions, or firmware update instructions, but is not limited to these.

[0025] Furthermore, the implementation method of the headphone charging system can be as follows: Figure 2 As shown, in Figure 2 In this embodiment, the charging device 102 may include a DC-DC converter circuit 202, a control circuit 204, a current adjustment circuit 206, a sensing circuit 208, and a rechargeable battery 210. The control circuit 204 is coupled to the DC-DC converter circuit 202, the current adjustment circuit 206, and the sensing circuit 208. The DC-DC converter circuit 202 is coupled to the current adjustment circuit 206 and the rechargeable battery 210. The current adjustment circuit 206 is coupled to the signal output terminal of the charging device 102, and the sensing circuit 208 is coupled to the signal output terminal of the charging device 102. Furthermore, in addition to the charging circuit 106 and the headphone battery 108, the headphone device 104 also includes a control circuit 214, an impedance circuit 216, and a sensing circuit 218. The control circuit 214 is coupled to the charging circuit 106, the impedance circuit 216, and the sensing circuit 218. The impedance circuit 216 is coupled to the charging current setting pin Iset of the control circuit 214 and the charging circuit 106. The sensing circuit 218 is also coupled to the signal input terminal of the headphone device 104.

[0026] The rechargeable battery 210 can provide DC voltage to the DC-DC converter circuit 202, which then converts the DC voltage into an output voltage. The DC-DC converter circuit 202 can be, for example, a boost circuit, but is not limited thereto. The control circuit 204 can control the current adjustment circuit 206 to generate a charging current IC1 based on the output voltage provided by the DC-DC converter circuit 202, and control the current adjustment circuit 206 to adjust the charging current IC1 between a first current and a second current, so as to transmit the data to be transmitted by the control circuit 204 to the headphone device 104. The current adjustment circuit 206 can be as follows: Figure 3 As shown, the circuit includes resistors R5 and R6 and transistor Q3. The emitter and collector of transistor Q3 are respectively coupled to the output terminal of DC-DC converter circuit 202 and the signal output terminal of charging device 102. Resistor R5 is coupled between the base and emitter of transistor Q3, and resistor R6 is coupled between the base of transistor Q3 and control circuit 204. Control circuit 204 can adjust the current value of charging current IC1 generated at the collector of transistor Q3 by controlling the conduction state of transistor Q3, for example, adjusting charging current IC1 to switch between a first current and a second current. It is worth noting that the implementation of current adjustment circuit 206 is not limited to this embodiment. For example, in some embodiments, resistor R6 may be omitted.

[0027] In the headphone device 104, the sensing circuit 218 can sense the voltage change caused by the current change of the charging current IC1, and generate a corresponding sensing signal to the control circuit 214. The control circuit 214 can determine the data transmitted by the charging device 102 based on the sensing signal. For example, the sensing circuit 218 can generate a first voltage and a second voltage in response to the sensed first current and second current. The first voltage and the second voltage can, for example, represent the transmitted data as "0" and "1" respectively. The control circuit 214 can determine the data transmitted by the charging device 102 based on the first voltage and the second voltage generated in sequence. The implementation of the sensing circuit 218 can be as follows: Figure 3 As shown, the sensing circuit includes resistors R7-R10 and R15, transistor Q2, and capacitor C2. Capacitor C2 is coupled between the signal input terminal of the headphone device 104 and one end of resistor R9, while the other end of resistor R9 is coupled to a reference voltage V4. Resistors R10 and R15 are connected in series between the common junction of capacitor C2 and resistor R9 and the base of transistor Q2. Resistor R8 is coupled between the base of transistor Q2 and ground. Resistor R7 is coupled between the reference voltage V3 and the collector of transistor Q2. The collector of transistor Q2 is coupled to control circuit 214, and the emitter of transistor Q2 is coupled to ground. The sensing signal can be generated at the collector of transistor Q2. It is worth noting that the implementation of sensing circuit 218 is not limited to this embodiment. For example, in some embodiments, resistors R7-R10 and R15 may be omitted from sensing circuit 218.

[0028] On the other hand, the control circuit 214 in the headphone device 104 can control the impedance circuit 216 to change its impedance, thereby causing the charging circuit 106 to adjust the charging current IC1 between a first current and a second current in response to the impedance change of the impedance circuit 216. Specifically, the impedance circuit 216 of the headphone device 104 can be configured as follows: Figure 3 As shown, the circuit includes resistors R11-R13 and transistor Q4. The collector of transistor Q4 is coupled to the charging current setting pin Iset of charging circuit 106. Resistor R11 is coupled between the base and emitter of transistor Q4, resistor R12 is coupled between the base of transistor Q4 and control circuit 214, and resistor R13 is coupled between the emitter of transistor Q4 and ground. Control circuit 214 can control the conduction state of transistor Q4 to change the impedance of impedance circuit 216, thereby adjusting the current value of charging current IC1 for data transmission. However, the implementation of adjusting the current value of charging current IC1 is not limited to this embodiment. For example, in some embodiments, the firmware design provided by charging circuit 106 can be used to adjust the current value of charging current IC1, and impedance circuit 216 can be omitted.

[0029] The sensing circuit 208 of the charging device 102 can sense the change in current of the charging current IC1, causing a change in the voltage entering capacitor C1, and generating a corresponding sensing signal to the control circuit 204. The control circuit 204 can determine the data transmitted by the headphone device 104 based on the sensing signal of the sensing circuit 208. Similarly, the sensing circuit 208 can generate a first voltage and a second voltage in response to the sensed first current and second current. The first voltage and the second voltage can, for example, represent transmitted data as "0" and "1" respectively. The control circuit 204 can determine the data transmitted by the headphone device 104 based on the first voltage and the second voltage generated in sequence. In detail, the implementation of the sensing circuit 208 can be as follows: Figure 3 As shown, the circuit includes resistors R1-R4 and R14, transistor Q1, and capacitor C1. Capacitor C1 is coupled between the signal output terminal of charging device 102 and one end of resistor R3, while the other end of resistor R3 is coupled to reference voltage V2. Resistors R4 and R14 are connected in series between the common junction of capacitor C1 and resistor R3 and the base of transistor Q1. Resistor R2 is coupled between the base of transistor Q1 and ground, and resistor R1 is coupled between reference voltage V1 and the collector of transistor Q1. The collector of transistor Q1 is coupled to control circuit 204, and the emitter of transistor Q1 is coupled to ground. The sensing signal can be generated at the collector of transistor Q1. Similarly, the implementation of sensing circuit 208 is not limited to this embodiment. For example, in some embodiments, resistors R1-R4 and R14 may be omitted from sensing circuit 208.

[0030] In some embodiments, in addition to determining the data transmitted by the headphone device 104 through the sensing signal of the sensing circuit 208, the control circuit 204 can also determine whether the headphone device 104 can receive the data transmitted by the charging device 102 by sensing the signal obtained by the sensing circuit 208 sensing the charging current IC1 when controlling the current adjustment circuit 206 to adjust the charging current IC1 for data transmission. That is, it can determine whether the charging current IC1 provided by the signal output terminal of the charging device 102 is transmitting data correctly. If it is determined that the charging current IC1 provided by the signal output terminal of the charging device 102 is not transmitting data correctly, the control circuit 204 controls the current adjustment circuit 206 to readjust the charging current IC1 (e.g., adjust the current level of the charging current IC1 or fine-tune the current values ​​of the first current and the second current) to ensure that the charging device 102 can transmit data correctly. In addition, in some embodiments, the headphone device 102 can also adjust the current level that the sensing circuit 218 can sense according to the magnitude of the received charging current IC1 (e.g., adjust the value of the capacitor or resistor in the sensing circuit 218) to correctly receive the transmitted data.

[0031] Figure 4This is a flowchart of a charging method for an earphone charging system according to an embodiment of the present invention, wherein the earphone charging system includes an earphone device and a charging device. As can be seen from the above embodiment, the charging method of the earphone charging system may include the following steps: First, a charging current is provided through the charging device (step S402). Next, the earphone battery of the earphone device is charged by the charging circuit of the earphone device according to the charging current (step S404). Then, the earphone device or the charging device is controlled to adjust the charging current between a first current and a second current to perform data transmission between the earphone device and the charging device (step S406). The earphone device may include an impedance circuit coupled to a charging current setting pin of the charging circuit. When the earphone device performs data transmission, the impedance of the impedance circuit can be adjusted, causing the charging circuit to adjust the charging current between the first current and the second current in response to the impedance change of the impedance circuit. Furthermore, in some embodiments, when the charging current adjusted by the charging device is used for data transmission, the headphone device can determine whether it can receive the data transmitted by the charging device based on the sensing signal generated by sensing the charging current. That is, the charging device 102 generates different charging currents IC1, which flow through the internal resistance of the charging circuit 106 of the headphone device 104 to generate different voltages. The sensing circuit 208 then determines whether the headphone device 104 can receive the data transmitted by the charging device 102 (in some embodiments, since the sensing circuit 208 of the charging device 102 and the sensing circuit 218 of the headphone device 104 are the same circuit, if the sensing circuit 208 can receive the data transmitted by the charging device 102, it means that the sensing circuit 218 can also receive the data), so as to determine whether the charging current provided by the charging device is transmitting data correctly.

[0032] In summary, the headphone device or charging device of the present invention can adjust the charging current of the charging device to charge the headphone battery to switch between a first current and a second current, so as to transmit data between the headphone device and the charging device, thereby realizing bidirectional communication between the charging device and the headphone device.

[0033] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A headphone charging system, characterized in that, include: Headphone device; as well as A charging device is provided, wherein its signal output terminal is coupled to the signal input terminal of the earphone device. The charging device accommodates and couples to the earphone device, provides charging current, and adjusts the charging current between a first current and a second current to facilitate data transmission between the earphone device and the charging device. The earphone device includes: Headphone batteries; A charging circuit is coupled to the signal input terminal of the earphone battery and the earphone device. The charging circuit has a charging current setting pin, and the charging circuit charges the earphone battery according to the charging current. A first control circuit, coupled to the charging circuit, controls the charging circuit to adjust the charging current to switch between the first current and the second current; An impedance circuit, coupled to the first control circuit and the charging current setting pin, is controlled by the first control circuit to change its impedance. The charging circuit responds to the impedance change of the impedance circuit by adjusting the charging current to switch between the first current and the second current; and A first sensing circuit, coupled to the first control circuit and the signal input terminal of the earphone device, senses the charging current to generate a first sensing signal. The first control circuit determines the data transmitted by the charging device based on the first sensing signal. The charging device includes: Second control circuit; A current adjustment circuit, coupled to the second control circuit and the signal output terminal of the charging device, is controlled by the second control circuit to adjust the charging current between the first current and the second current; and The second sensing circuit is coupled to the signal output terminal of the second control circuit and the charging device to sense the charging current and generate a second sensing signal. The second control circuit determines the data transmitted by the earphone device based on the second sensing signal.

2. The headphone charging system according to claim 1, characterized in that, The impedance circuit includes: A transistor, the collector and emitter of which are respectively coupled to the charging current setting pin and the ground voltage, and the base of the transistor is coupled to the first control circuit; and A resistor is coupled between the base and emitter of the transistor, and the first control circuit controls the conduction state of the transistor to adjust the impedance of the impedance circuit.

3. The headphone charging system according to claim 1, characterized in that, The first sensing circuit includes: A capacitor, one end of which is coupled to the signal input terminal of the headphone device; and A transistor, the base of which is coupled to the other end of the capacitor, the collector and emitter of which are coupled to the operating voltage and the ground voltage, respectively, the collector of which is also coupled to the first control circuit, and the first sensing signal is generated at the collector of the transistor.

4. The headphone charging system according to claim 1, characterized in that, The charging device further includes: Rechargeable batteries provide DC voltage; and A DC-DC converter circuit is coupled to the rechargeable battery, the current adjustment circuit, and the second control circuit to convert the DC voltage into an output voltage. The current adjustment circuit generates the charging current based on the output voltage.

5. The headphone charging system according to claim 4, characterized in that, The current adjustment circuit includes: A transistor, the emitter and collector of which are respectively coupled to the signal output terminals of the DC-DC conversion circuit and the charging device, and the base of the transistor being coupled to the second control circuit; and A resistor is coupled between the emitter and base of the transistor, and the second control circuit controls the conduction state of the transistor to adjust the charging current.

6. The headphone charging system according to claim 4, characterized in that, The second control circuit controls the current adjustment circuit to adjust the current value of the charging current, and determines whether the earphone device can receive the data transmitted by the charging device based on the second sensing signal.

7. A charging method for an earphone charging system, the earphone charging system comprising an earphone device and a charging device, characterized in that, The signal output terminal of the charging device is coupled to the signal input terminal of the earphone device, and the charging method of the earphone charging system includes: The charging device provides charging current; The headphone device's battery is charged via the charging circuit according to the charging current, wherein the headphone device further includes an impedance circuit coupled to a charging current setting pin of the charging circuit; and The system controls the earphone device and the charging device to adjust the charging current between a first current and a second current to facilitate data transmission between the earphone device and the charging device. The step of controlling the earphone device and the charging device to adjust the charging current to switch between the first current and the second current in order to perform data transmission between the earphone device and the charging device includes: The charging current is adjusted by the current adjustment circuit of the charging device to switch between the first current and the second current. The charging current is sensed through the sensing circuit of the earphone device to generate a first sensing signal; The data transmitted by the charging device is determined based on the first sensing signal; The impedance of the impedance circuit of the headphone device is adjusted so that the charging circuit responds to the impedance change of the impedance circuit and adjusts the charging current to switch between the first current and the second current. The charging current is sensed through the sensing circuit of the charging device to generate a second sensing signal; and The data transmitted by the earphone device is determined based on the second sensing signal.

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