A voltage modulation circuit for a charging communication multiplex port and TWS earphones

Abstract

This invention relates to a voltage modulation circuit for a charging communication multiplexed port and TWS earphones, belonging to the field of charging chip technology. The voltage modulation circuit includes: a modulation signal generator, a voltage rate controller, a voltage converter, a serial communication switch Q2, a discharge switch Q1, and a resistor R1. The modulation signal generator modulates the voltage of the output signal VOUT of the voltage converter through the voltage rate controller, controlling the voltage swing range of the output signal VOUT within the normal input voltage range of the earphones. The modulation signal generator also modulates the frequency of the output signal VOUT of the voltage converter through the voltage rate controller to send communication control commands. Therefore, the voltage modulation circuit provided by this invention can provide customized communication control commands from the charging case to the earphones (master and slave devices) without interfering with the charging and power supply of the earphones, simplifying the command implementation method of the charging case, and has the advantages of simple circuitry and high stability.

Description

Technical Field

[0001] This invention relates to the field of charging chip technology, and in particular to a voltage modulation circuit for a charging communication multiplexing port and a TWS earphone. Background Technology

[0002] With the increasing popularity of TWS (True Wireless Stereo) Bluetooth earbuds, the market has placed higher demands on the integration of dedicated TWS charging chip solutions. These solutions typically employ a two-wire charging approach to minimize the number of connector contacts. However, existing TWS charging case-earbud charging systems integrate charging chip circuits that only have charging functionality. The circuitry for communication and control between the charging case and the earbuds is separate from the charging circuitry, resulting in a generally complex circuit structure and unstable operation. Summary of the Invention

[0003] The purpose of this invention is to provide a voltage modulation circuit for a charging communication multiplexing port and a TWS earphone, which can provide customized communication control commands from the charging case to the earphone without interfering with the earphone charging, simplifying the command implementation of the charging case and improving the working stability.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A voltage modulation circuit for a charging communication multiplex port includes: a modulation signal generator, a voltage rate controller, a voltage converter, a serial communication switching switch Q2, a discharge switch Q1, and a resistor R1.

[0006] The input terminal of the modulation signal generator is connected to the TX signal; the output terminal of the modulation signal generator is connected to the input terminal of the voltage rate controller; the first output terminal of the voltage rate controller is connected to the first input terminal of the voltage converter; the second input terminal of the voltage converter is connected to the VIN power supply; the output terminal of the voltage converter is connected to the source of the serial communication switch Q2; the drain of the serial communication switch Q2 outputs the signal VOUT; one end of the resistor R1 is connected to the drain of the serial communication switch Q2; the other end of the resistor R1 is connected to the source of the discharge switch Q1; the drain of the discharge switch Q1 is grounded; the gate of the discharge switch Q1 is connected to the second output terminal of the voltage rate controller.

[0007] The modulation signal generator modulates the voltage of the output signal VOUT of the voltage converter through the voltage rate controller, controlling the voltage swing range of the output signal VOUT within the normal input voltage range of the headphones; the modulation signal generator modulates the frequency of the output signal VOUT of the voltage converter through the voltage rate controller to send communication control commands.

[0008] Optionally, the voltage swing range of the output signal VOUT is 5.2V (high voltage) and 4.5V (low voltage).

[0009] Optionally, when the frequency of the output signal VOUT is 1kHz and the period is 1ms, it represents output data 0; when the frequency of the output signal VOUT is 2kHz and the period is 0.5ms, it represents output data 1.

[0010] Optionally, the communication control command consists of an initialization signal INIT, a data packet identification signal ID Code, a data transmission start signal START, a command control signal DATA, a check bit Check SUM, and a stop bit STOP.

[0011] Optionally, the serial communication switch Q2 is turned on during voltage modulation and remains off in UART serial communication mode.

[0012] Optionally, the serial communication switching switch Q2 is a PMOS transistor; the discharge switch Q1 is an NMOS transistor.

[0013] Optionally, the voltage converter operates in light-load PFM mode.

[0014] A TWS earphone includes a main control module, a register, a serial port module, and a voltage modulation circuit; the main control module is connected to the register and the serial port module respectively, and the register is connected to the modulation signal generator in the voltage modulation circuit.

[0015] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0016] This invention provides a voltage modulation circuit for a charging communication multiplexed port and a TWS earphone. The voltage modulation circuit includes: a modulation signal generator, a voltage rate controller, a voltage converter, a serial communication switch Q2, a discharge switch Q1, and a resistor R1; the input terminal of the modulation signal generator is connected to the TX signal; the output terminal of the modulation signal generator is connected to the input terminal of the voltage rate controller; the first output terminal of the voltage rate controller is connected to the first input terminal of the voltage converter; the second input terminal of the voltage converter is connected to the VIN power supply; the output terminal of the voltage converter is connected to the source of the serial communication switch Q2; the drain of the serial communication switch Q2 outputs the signal VOUT; and the resistor R1... One end of the resistor R1 is connected to the drain of the serial communication switch Q2; the other end of the resistor R1 is connected to the source of the discharge switch Q1; the drain of the discharge switch Q1 is grounded; the gate of the discharge switch Q1 is connected to the second output terminal of the voltage rate controller; the modulation signal generator modulates the voltage of the output signal VOUT of the voltage converter through the voltage rate controller, controlling the voltage swing range of the output signal VOUT within the normal input voltage range of the headphones; the modulation signal generator modulates the frequency of the output signal VOUT of the voltage converter through the voltage rate controller to send communication control commands. Therefore, the voltage modulation circuit provided by this invention can provide customized communication control commands from the charging case to the headphones (master and slave devices) without interfering with the charging and power supply of the headphones, simplifying the command implementation method of the charging case, and has the advantages of simple circuit and high stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the voltage modulation circuit of the charging communication multiplexing port provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the voltage waveform of the output signal VOUT provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the data structure of the communication control command provided in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of a TWS earphone provided in an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a voltage modulation circuit for a charging communication multiplexing port and a TWS earphone, which can provide customized communication control commands from the charging case to the earphone without interfering with the earphone charging, and simplify the command implementation method of the charging case.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a schematic diagram of the voltage modulation circuit for a charging communication multiplexing port provided in an embodiment of the present invention. See also... Figure 1 The voltage modulation circuit of the charging communication multiplexing port includes: a pattern generator, a DAC & SR controller, a DC-DC converter, a serial communication switch Q2, a discharge switch Q1, and a resistor R1. In one specific embodiment, the serial communication switch Q2 is a PMOS transistor; the discharge switch Q1 is an NMOS transistor.

[0026] The input terminal of the modulation signal generator is connected to the TX signal; the TX signal serves as the input signal of the voltage modulation circuit and can specify the specific command control content to be sent.

[0027] The output terminal of the modulation signal generator is connected to the input terminal of the voltage rate controller; the first output terminal of the voltage rate controller is connected to the first input terminal of the voltage converter; the second input terminal of the voltage converter is connected to the VIN power supply; the output terminal of the voltage converter is connected to the source of the serial communication switch Q2; the drain of the serial communication switch Q2 outputs the signal VOUT; one end of the resistor R1 is connected to the drain of the serial communication switch Q2; the other end of the resistor R1 is connected to the source of the discharge switch Q1; the drain of the discharge switch Q1 is grounded; the gate of the discharge switch Q1 is connected to the second output terminal of the voltage rate controller. The serial communication switch Q2 can be turned on during voltage modulation and remains off in UART serial communication mode.

[0028] The modulation signal generator modulates the voltage of the output signal VOUT of the voltage converter through the voltage rate controller, controlling the voltage swing range of the output signal VOUT within the normal input voltage range of the headphones to power them. During the switching process of the output voltage of the voltage rate controller from a higher value to a lower value, the discharge switch Q1 automatically turns on to automatically discharge the output voltage of the voltage converter. After the voltage adjustment is complete, the discharge switch Q1 automatically turns off, further preventing any impact on system energy efficiency. In a specific embodiment of the invention, as an example, to ensure that the load (headphones) does not lose power during the command transmission process, the voltage swing range of the output signal VOUT can be set to a high voltage (VH) of 5.2V and a low voltage (VL) of 4.5V.

[0029] The modulation signal generator modulates the frequency of the output signal VOUT of the voltage converter through the voltage rate controller, thereby enabling the transmission of communication control commands. Figure 2 This is a schematic diagram of the voltage waveform of the output signal VOUT provided in an embodiment of the present invention. See also... Figure 2 The voltage modulation circuit sends signals by frequency modulation: for example, when the frequency of the output signal VOUT is 1kHz and the period is 1ms, it indicates output data 0 ([0] for 1ms); when the frequency of the output signal VOUT is 2kHz and the period is 0.5ms, it indicates output data 1 ([1] for 0.5ms).

[0030] As an example, this embodiment of the invention can power the earphones normally by controlling the voltage of the output signal VOUT, and send communication control commands by controlling the frequency of the output signal VOUT. This realizes the voltage modulation circuit of the charging communication multiplexing port, which can send customized communication control command data packets by adjusting the main line voltage without affecting the normal power supply mode, thereby realizing the communication connection between the master and slave devices (charging case and earphones).

[0031] Figure 3 A schematic diagram of the data structure of the communication control command provided in an embodiment of the present invention is shown below. Figure 3The communication control command sent by VOUT consists of the initialization signal INIT, the data packet identification signal ID Code, the data transmission start signal START, the command control signal DATA, the check bit Check SUM, and the stop bit STOP. The signal definitions included in the communication control command are adapted and defined by the earphones and the charging case from the system's underlying layer. Through this communication control command, the charging case (master device) can issue commands such as power off / restart / enter transport mode / establish UART (Universal Asymchronous Receiver Transmitter) communication to the earphones (slave device). The voltage modulation circuit provided in this embodiment of the invention integrates the above-mentioned communication and control commands, simplifying the implementation of commands in the charging case, thereby simplifying the circuit structure, making system control or UART communication establishment more flexible and convenient, and ensuring more stable circuit operation.

[0032] The present invention also provides an embodiment of TWS earphones. Figure 4 This is a schematic diagram of the structure of a TWS earphone provided in an embodiment of the present invention. See also... Figure 4 The TWS earphone includes: a main control module (MCU), a register (Register), a serial port module (UART), and a voltage modulation circuit for a charging communication multiplexed port. The voltage modulation circuit includes: a modulation signal generator (PatternGenerator), a voltage rate controller (DAC&SR controller), a voltage converter (DCDC Converter), a serial communication switch (Q2), a discharge switch (Q1), and a resistor (R1). The MCU is connected to the UART and communicates using the UART protocol. The UART is also connected to the drain of the serial communication switch (Q2). The MCU is also connected to the register (Register) and communicates using the I2C protocol. The register (Register) is connected to the pattern generator (PatternGenerator). The MCU generates control commands and sends them to the register (Register), which then sends these commands as TX signals to the pattern generator (PatternGenerator).

[0033] In this embodiment of the invention, the instruction sending process of the voltage modulation circuit is as follows: When the system needs to send instructions and control signals, a TX signal is input, which specifies the specific instructions and control content to be sent. A corresponding voltage control signal is generated by the modulation signal generator and sent to the voltage rate controller. The voltage rate controller controls the voltage converter to generate a voltage modulation signal, which is output through the serial communication switch Q2 to form the output signal VOUT. The voltage swing range of this voltage modulation signal should ensure that the load (earphone) can maintain power supply under any circumstances; for example, it is set to a high level of 5.2V and a low level of 4.5V.

[0034] This invention aims to achieve command transmission by using a voltage modulation circuit structure that generates a stable voltage source with sufficient load capacity to support the load. In the voltage modulation circuit provided in this invention, as an example, on the one hand, a voltage rate controller controls the output voltage swing range of the voltage converter to be within the normal input voltage range of the load (headphones), ensuring that the load (headphones) does not lose power during command transmission (e.g., the headphone battery runs out of power); on the other hand, when the voltage rate controller controls the high and low level switching of the output voltage VOUT of the voltage converter, the switching rate of the output voltage VOUT of the voltage converter must meet the definition requirements of the command. This is because a VOUT switching rate that is too fast may cause output voltage overshoot or undershoot, and when the voltage changes from low to high, it may cause a large input current spike in the voltage converter, potentially pulling down the input VIN; a VOUT switching rate that is too slow may fail to meet the rise and fall rate requirements of the VOUT modulation signal.

[0035] To prevent reverse current from flowing from VOUT to VIN under any circumstances, which could cause overvoltage at VIN, this embodiment of the invention configures the voltage converter to operate in a light-load PFM (Pulse Frequency Modulation) mode, where its internal zero-crossing detection circuit blocks reverse current. Therefore, during the transition of VOUT from high voltage to low voltage, the discharge switch Q1 remains on to force the output voltage to decrease at a predetermined rate.

[0036] Based on this, the present invention proposes a voltage modulation circuit embodiment for a charging communication multiplexing port, which has the advantages of simple circuit and strong stability. It can provide transmission communication and control commands through the charging circuit without interfering with charging and power supply.

[0037] In one embodiment of the present invention, a modulation signal generator is added to a TWS charging case-earphone charging system, a portable device fast charging system, or a two-wire power supply / communication system. This modulation signal generator modulates the output voltage VOUT of the voltage converter via a voltage rate controller, thereby transmitting communication and control command data packets to control the earphones (load). Compared to existing TWS or portable device charging systems, the voltage modulation circuit of the charging communication multiplexing port provided in this embodiment of the present invention has at least the following advantages:

[0038] 1. Low cost; Since the IC is positioned as an earphone charging IC, it has already integrated a voltage rate controller and a voltage converter (the earphone charging IC also integrates a serial port module UART, which is not involved in the voltage modulation circuit embodiment of this invention and will not be described in detail here). Only a modulation signal generator needs to be added according to the modulation requirements, so the modification cost is extremely low.

[0039] 2. This voltage modulation circuit structure can send commands without affecting the power supply of the headphones (load); because the modulation voltage of this voltage modulation circuit is allowed to be modulated within the normal power supply range of the headphones (load) (for example, the communication low level is defined as 4.5V and the high level is defined as 5.2V), and this voltage modulation circuit structure directly controls the output signal VOUT of the voltage converter, it also has sufficient current capability during the command sending process to meet the charging needs of the headphones;

[0040] 3. Simple and reliable structure: This voltage modulation circuit directly controls the output signal VOUT of the voltage converter, without any stability issues and with a good overload protection mechanism. It has the advantages of simple and reliable circuit and strong stability.

[0041] In another embodiment of the art, voltage modulation can be achieved by an LDO (low dropout regulator), but an LDO requires an additional LDO circuit, which is more expensive and less stable than the voltage modulation circuit structure provided in the embodiments of the present invention. In addition, LDO cannot provide power efficiently and its output current capability is also much lower than that of the voltage modulation circuit structure provided in the embodiments of the present invention.

[0042] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the control method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A voltage modulation circuit for a charge communication multiplexed port, the voltage modulation circuit comprising: Comprising: a modulation signal generator, a voltage rate controller, a voltage converter, a serial communication switching switch Q2, a discharge switch Q1 and a resistor R1; an input end of the modulation signal generator is connected with a TX signal; an output end of the modulation signal generator is connected with an input end of the voltage rate controller; a first output end of the voltage rate controller is connected with a first input end of the voltage converter; a second input end of the voltage converter is connected with a VIN power supply; an output end of the voltage converter is connected with a source electrode of the serial communication switching switch Q2; a drain electrode of the serial communication switching switch Q2 is led out to output a signal VOUT; one end of the resistor R1 is connected with the drain electrode of the serial communication switching switch Q2; the other end of the resistor R1 is connected with a source electrode of the discharge switch Q1; a drain electrode of the discharge switch Q1 is connected with the ground; a gate electrode of the discharge switch Q1 is connected with a second output end of the voltage rate controller; the modulation signal generator modulates the voltage of the output signal VOUT of the voltage converter through the voltage rate controller, and controls the voltage swing range of the output signal VOUT within the normal input voltage range of the earphone; the modulation signal generator modulates the frequency of the output signal VOUT of the voltage converter through the voltage rate controller, and realizes sending a communication control instruction.

2. The voltage modulation circuit of claim 1, wherein, The voltage swing range of the output signal VOUT is 5.2V high voltage and 4.5V low voltage.

3. The voltage modulation circuit of claim 1, wherein, When the frequency of the output signal VOUT is 1kHz and the period is 1ms, it represents output data 0; when the frequency of the output signal VOUT is 2kHz and the period is 0.5ms, it represents output data 1.

4. The voltage modulation circuit of claim 1, wherein, The communication control instruction is composed of an initialization signal INIT, a data packet identification signal ID Code, a data sending start signal START, an instruction control signal DATA, a check bit CheckSUM and a termination bit STOP.

5. The voltage modulation circuit according to any one of claims 1 to 4, characterized in that, The serial communication switching switch Q2 is turned on in the voltage modulation process, and is kept off in the UART serial communication mode.

6. The voltage modulation circuit of claim 1, wherein, The serial communication switching switch Q2 is a PMOS tube; the discharge switch Q1 is an NMOS tube.

7. The voltage modulation circuit of claim 1, wherein, The voltage converter works in a light load PFM mode.

8. A TWS earphone, comprising a master control module, a register and a serial port module, the master control module being connected with the register and the serial port module respectively, characterized in that, Further comprising the voltage modulation circuit according to any one of claims 1-7; the register is connected with the modulation signal generator in the voltage modulation circuit.

Images