CN108521872B

CN108521872B - Earphone control device and wired earphone

Info

Publication number: CN108521872B
Application number: CN201880000748.8A
Authority: CN
Inventors: 段红亮; 杨旺旺; 刘畅
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2018-04-12
Filing date: 2018-04-12
Publication date: 2021-03-19
Anticipated expiration: 2038-04-12
Also published as: CN108521872A; WO2019196054A1

Abstract

A control device of a headset and a wired headset are provided. The control device includes: a voltage protection circuit; when the earphone is inserted into the terminal equipment, the voltage protection circuit is connected with the power supply end of the terminal equipment through the microphone end of the earphone, the voltage protection circuit is used for receiving the voltage output by the power supply end through the microphone end and outputting a first voltage, wherein the voltage output by the power supply end is greater than or equal to the first voltage. In the embodiment of the invention, the voltage protection circuit is arranged in the earphone, so that the situation that the back-end circuit of the earphone is damaged when the voltage output by the power supply end of the terminal equipment is overlarge can be avoided.

Description

Earphone control device and wired earphone

Technical Field

The embodiment of the invention relates to the technical field of electronics, in particular to a control device of an earphone and a wired earphone.

Background

With the rise of wearable health auxiliary equipment, heart rate measurement becomes the most common physiological state detection index at present, and the ear has abundant capillary vessel, has very big advantage on measuring physiological signals such as heart rate, blood pressure, blood oxygen, possesses the basic condition who carries out heart rate measurement. There is currently a wireless heart rate detection headset on the market. Specifically, the earphone is connected with the intelligent terminal through Bluetooth (Bluetooth), and heart rate data or calculation results are transmitted to the mobile phone. However, such earphones require a built-in battery, require recharging, and are costly and expensive. However, if the output voltage of the mobile phone is increased to a relatively high value (for example, 5V), when the earphone is inserted into the mobile phone, the circuit at the back end may be damaged due to an excessively high voltage.

Disclosure of Invention

In order to solve the above problem, the present application provides a control device for an earphone and a wired earphone, which can prevent a back-end circuit of the earphone from being damaged when a voltage output by a power supply terminal of a terminal device is too large.

In one aspect, a control device for a headset is provided, including:

the earphone comprises a voltage protection circuit, wherein when the earphone is inserted into the terminal equipment, the voltage protection circuit is connected with a power supply end of the terminal equipment through a microphone end of the earphone, the voltage protection circuit is used for receiving voltage output by the power supply end through the microphone end and outputting first voltage, and the voltage output by the power supply end is greater than or equal to the first voltage.

In the embodiment of the invention, the voltage protection circuit is arranged in the earphone, so that when the voltage of the power supply end of the terminal equipment is higher than the first voltage, the voltage from the terminal equipment can be converted into the first voltage to be output. Namely, when the voltage output by the power supply end is too large, the voltage limiting processing of the voltage protection circuit can avoid damaging the back end circuit of the voltage protection circuit.

In another aspect, there is provided a wired headset including: the control device of the first aspect.

Drawings

Fig. 1 is a schematic structural diagram of a wired headset having a 3.5mm audio jack according to an embodiment of the present invention.

Fig. 2 is an exemplary diagram of a 3.5mm audio interface of a terminal device corresponding to a 3.5mm audio jack, in accordance with an embodiment of the present invention.

FIG. 3 is a schematic block diagram of a biometric detection module of an embodiment of the present invention.

Fig. 4 and 5 are schematic views of the design position of the biometric detection module in the earplug according to the embodiment of the invention.

Fig. 6 is a schematic structural diagram of an earphone with a built-in biometric detection module according to an embodiment of the present invention.

Fig. 7 is a schematic diagram of the position of the reverse flow detection control circuit of the earphone according to the embodiment of the present invention.

Fig. 8 is a schematic diagram of the location of a supply voltage control circuit of an earphone according to an embodiment of the present invention.

Fig. 9 is a schematic diagram of the location of the voltage protection circuit of the headset of an embodiment of the present invention.

Fig. 10 is a schematic diagram of the location of the signal isolation circuit of the headset of an embodiment of the present invention.

Fig. 11 is a schematic block diagram of a headset of an embodiment of the present invention.

Fig. 12 is a voltage waveform diagram of a power supply terminal of a terminal device according to an embodiment of the present invention when the power supply terminal is in sleep.

Fig. 13 is a voltage waveform diagram of the power supply terminal of the terminal device with the power supply terminal dormant after the power-taking circuit works according to the embodiment of the invention.

Fig. 14 is an exemplary diagram of one circuit design of a headset of an embodiment of the present invention.

Fig. 15 is a diagram showing an exemplary configuration of the first voltage detection control circuit according to the embodiment of the present invention.

Fig. 16 is another exemplary configuration diagram of the first voltage detection control circuit of the embodiment of the present invention.

Fig. 17 is an exemplary diagram of another circuit design for a headset of an embodiment of the present invention.

Detailed Description

The technical solution of the embodiment of the present invention is described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a wired headset having a 3.5mm audio jack according to an embodiment of the present invention. Fig. 2 is an exemplary diagram of a 3.5mm audio interface of a terminal device corresponding to the 3.5mm audio connector 110b of an embodiment of the present invention. As shown in fig. 1, the wired headset 100 includes: a 3.5mm audio jack 110b, an earphone cord 120, a line control board 130 and earpieces 140. Wherein, the 3.5mm audio connector 110b can be divided into: a Microphone (MIC) communication connector 111b, a device Ground (GND) potential connector 112b, a right ear plug horn connector 113b, and a left ear plug horn connector 114 b. When the 3.5mm audio connector 110b shown in fig. 1 is connected to the smart terminal (i.e., the earphone is inserted into the smart terminal), the Microphone (MIC) communication connector 111b, the device Ground (GND) potential connector 112b, the right ear plug speaker connector 113b, and the left ear plug speaker connector 114b shown in fig. 1 are respectively connected to the Microphone (MIC) communication interface 111a, the device Ground (GND) interface 112a, the right speaker interface 113a, and the left speaker interface 114a shown in fig. 2, wherein the microphone communication interface 111a, the device ground interface 112a, the right speaker interface 113a, and the left speaker interface 114a constitute the audio interface 110a of the terminal device. In actual practice, a Digital to analog converter (DAC) converts a Digital signal into an analog signal (in the form of current, voltage or charge) to communicate with or power the headset. Further, the microphone communication interface 111a is connected to an internal power level 152 of the terminal device, and the internal power level 152 provides a power supply voltage for the earphone through the microphone communication interface 111a, and in some embodiments, the microphone communication interface 111a may also be referred to as a power supply terminal of the terminal device, and for convenience of description, the power supply terminal of the terminal device is taken as an example below. It should be understood that conventional wired headsets typically have only a few basic functions of voice transmission and music playing and key operation. The wired earphone 100 according to an embodiment of the present invention may have a biometric detection module built therein, and the biometric detection module may be any module capable of detecting a physiological state of a human body. For example, the physiological signal or circuit module may be a biometric detection module 711, a pressure detection module, a wear detection module, a blood pressure detection module, a body temperature detection module, a blood glucose detection module, a blood lipid detection module, and the like. It should also be understood that the present application is not limited to earbud headsets and is described herein as exemplary only. The wired earphone 100 according to an embodiment of the present invention may have a biometric display module built therein for displaying a detection result of the biometric detection module.

FIG. 3 is a schematic block diagram of a biometric detection module of an embodiment of the present invention. As shown in fig. 3, the biometric detection module 200 may include an acquisition module 220 and a calculation control module 210. The acquisition module 210 is configured to acquire raw heart rate data (or processed heart rate data, or calculated heart rate results); the calculation control module 210 may be configured to process and calculate the heart rate data acquired by the acquisition module 220; the calculation control module 210 can also be used for communicating with the mobile phone and the acquisition module 220; the calculation control module 210 may also be used to control the operation mode of the entire biometric detection module 200 or some modules or circuits in the biometric detection module 200. In one embodiment, the acquisition module 220 may include a heart rate sensor 221, a Light Emitting Diode (LED)224, an acceleration sensor 222, and an optical design module 225, and the heart rate sensor 224 may include a Photodiode (PD) 223. The heart rate sensor 221 controls the light emitting diode 224 to emit light, the emitted light is transmitted to the photodiode 223 after being acted by skin tissues, the heart rate sensor 221 processes optical signals received by the photodiode 223, quantizes the optical signals into electric signals, converts the electric signals into digital signals through the analog-digital conversion circuit, and finally transmits the digital signals to the standard digital communication interface. For example, I2C interface, SPI interface. In one embodiment, the calculation control module 210 may include a power supply control module 211, a Micro Control Unit (MCU) 212, and a Digital Signal Processing (DSP) circuit. The calculation control module 210 may be used to control the power supply, the operating mode, the calculation and indication of the measured heart rate results, etc. of the acquisition module 220.

Fig. 4 and 5 are schematic views of the design position of the biometric detection module 200 (and in particular the acquisition module 220) in an earplug. As shown in FIG. 4, an earplug 140 of an embodiment of the invention, as shown in FIG. 1, may comprise: an earbud component 141 and an acquisition module 220 as shown in fig. 3. In particular, the earbud member 141 can include: rear shell decoration, rearmounted shell, leading shell, silica gel cover. As shown in fig. 5, the earplug 140 may further include the horn module 142 and a plurality of wires 123c, and the wires 123c are respectively connected to the horn module 142 and the collecting module 220. The biometric detection module 200 (and particularly the acquisition module 220) in embodiments of the present invention may be located anywhere on the wired headset that can be placed proximate to the ear.

Fig. 6 is a schematic structural diagram of the headset with the biometric detection module 200 (especially, the acquisition module 220) built therein according to the embodiment of the present invention. As shown in fig. 6, the acquisition module 220 is disposed on the left earplug 340b, and the calculation control module 210 shown in fig. 3 can be disposed in the line control board 330. The beam splitter 322 serves to split the third beam 321 into a first beam 323-B and a second beam 323-a, and the first beam 323-B is connected to the third beam 323-C through the line control board 330. It should be understood that the connection relationship between the functional modules shown in fig. 6 is merely an exemplary description, and the embodiment of the present invention is not limited in particular. For example, as shown in fig. 6, the acquisition module 220 may be disposed on the left ear plug 340 b. In other embodiments, the collection module 220 may also be disposed on the right earpiece 340a, or both the right earpiece 340a and the left earpiece 340b, and so on. For another example, as shown in fig. 6, the calculation control module 210 may be disposed on the line control board 330. In other embodiments, the calculation control module 210 may be disposed on the right earplug 340a and/or the left earplug 340b, the calculation control module 210 may be integrated and disposed in the earphone, and the like. The embodiment of the present invention is not particularly limited.

The earphone in the embodiment of the invention does not need a battery, so that the earphone does not need to be charged and does not need to carry a charging cable or a charger. And the earphone is convenient to use, and can be used after being inserted into target equipment (such as a mobile phone), so that the production cost of the earphone is reduced. Further, the earphone in the embodiment of the invention can support the completion of heart rate measurement on the earphone and indicate the heart rate interval. However, when the headset integrated with the biometric detection module is inserted into a terminal device (e.g., a mobile phone), only a Microphone (MIC) line (i.e., a microphone terminal of the headset) has current, i.e., the mobile phone system receives a supply voltage only through the microphone terminal of the headset. When the current of the microphone of the earphone is too large or too small, the normal operation of the earphone is affected. In addition, the audio signal generated by the microphone is also transmitted to the mobile phone end through the MIC line of the mobile phone end. Therefore, for a device (such as a mobile phone output MIC line) transmitting a signal through a power line, the signal to be transmitted on the power line cannot be attenuated, and meanwhile, the signal on the power line cannot be interfered by power supply fluctuation generated by system work.

In one aspect, in order to solve the problem of too small current at the microphone of the headset or insufficient power supply capability at the headset plug of the terminal device, in the embodiment of the present invention, a storage circuit may be disposed in the headset for storing the charge from the microphone of the headset. Therefore, even if the power supply capacity at the earphone plug of the terminal equipment is insufficient, the energy storage circuit can supply power to the earphone normally, and the phenomenon that the voltage of the power supply terminal is reduced too much when the earphone consumes large current in the moment is prevented, so that the normal voice transmission function of the earphone is influenced.

On the other hand, in order to ensure that the charges stored in the energy storage circuit are not discharged reversely, in the embodiment of the invention, a reverse current detection control circuit can be configured for the earphone. As shown in fig. 7, the control device 400 of the earphone may include a reverse current detection control circuit 420, the microphone end 410 of the earphone is connected to the tank circuit 430 of the earphone through the reverse current detection control circuit 420, and the reverse current detection control circuit 420 is configured to compare the voltage in the tank circuit 430 with the voltage at the microphone end 410 of the earphone and control the electrical connection or the electrical disconnection between the tank circuit 430 and the microphone end 410 according to the comparison result of the reverse current detection control circuit 420.

On the other hand, in order to ensure that the earphone can normally operate when the power supply voltage of the earphone is still insufficient to drive each module or circuit in the earphone to normally operate even if the energy storage circuit exists, in an embodiment of the present invention, a power supply voltage control circuit may be further configured for the earphone, and the power supply voltage control circuit may control the power supply voltage or power consumption of at least one module or circuit in the earphone, and preferably, the power supply voltage control circuit may control the power supply voltage of the signal processing circuit in the earphone. For example, as shown in fig. 8, the control device 400 of the earphone may include a supply voltage control circuit 440, the microphone 410 of the earphone is connected to the input terminal of the tank circuit 430 of the earphone through the supply voltage control circuit 440, the output terminal of the tank circuit 430 is connected to the signal processing circuit 450 through the supply voltage control circuit 440, and the supply voltage control circuit 440 is configured to obtain a voltage condition of the microphone 410 of the earphone and/or a tank condition of the tank circuit 430 of the earphone, and control the supply voltage of the signal processing circuit 450 of the earphone according to the voltage condition of the microphone 410 and/or the tank condition of the tank circuit 430 of the earphone. In other words, the supply voltage control circuit 440 is configured to obtain the voltage at the microphone of the headset and/or the voltage condition of the energy storage circuit, so as to control the supply voltage or the operation mode of each module or circuit in the headset.

Correspondingly, aiming at the problem that the current of the microphone end of the earphone is too large or the power supply capacity at the earphone plug of the terminal equipment is too large, a voltage protection circuit can be arranged in the earphone. For example, as shown in fig. 9, the control device 400 of the earphone may include a voltage protection circuit 520, when the earphone is inserted into the terminal device, the voltage protection circuit 520 is connected to a power supply terminal of the terminal device through a microphone terminal 510 of the earphone, and the voltage protection circuit 520 is configured to receive a voltage output by the power supply terminal through the microphone terminal 510 and output a first voltage, where the voltage output by the power supply terminal is greater than or equal to the first voltage. The voltage protection circuit can convert the voltage output by the power supply end into the first voltage which is less than or equal to the output voltage of the power supply end, and the circuit at the rear end is prevented from being damaged when the voltage output by the power supply end is too large, so that the normal work of the earphone is influenced. As an example, when the voltage output by the power supply terminal is higher than a threshold voltage, the first voltage is equal to the threshold voltage, and when the voltage output by the power supply terminal is lower than the threshold voltage, the first voltage is equal to the voltage output by the power supply terminal. In other words, when the voltage output by the power supply terminal is higher than the threshold voltage, the voltage protection circuit 520 may be configured to output the threshold voltage, and when the voltage output by the power supply terminal is lower than the threshold voltage, the voltage protection circuit 520 may be configured to output the voltage output by the power supply terminal. For example, the threshold voltage is 2.8 volts. It should be understood that the voltage protection circuit 520 in the embodiment of the present invention is intended to perform voltage limiting processing on the voltage received by the microphone of the earphone, and the above-mentioned first voltage is equal to the threshold voltage when the voltage output by the power supply terminal is higher than the threshold voltage, and the first voltage is equal to the voltage output by the power supply terminal when the voltage output by the power supply terminal is lower than the threshold voltage is merely an exemplary description. For example, in other embodiments, the first voltage may be a voltage obtained by limiting the voltage output by the power supply terminal according to a certain proportional relationship.

In addition, in order to ensure that the power supply fluctuation generated by the system work does not attenuate the signal to be transmitted on the power line (such as the output MIC line of the mobile phone), a signal isolation circuit can be arranged in the earphone, so that the power supply fluctuation generated when the earphone works can not interfere with the signal transmitted on the power line. In an alternative embodiment, as shown in fig. 10, the control device 400 of the headset may include a signal isolation circuit 630, and the microphone end 610 of the headset is connected to one end of the signal isolation circuit 630 through the sound pickup circuit 620, wherein the sound pickup circuit 620 is used for converting the received sound signal into an electrical signal. The signal isolation circuit 630 is used to isolate interference between the electrical signal and the circuitry connected to the other end of the signal isolation circuit 630 (resulting power supply ripple).

The connection relationship among the voltage protection circuit, the reverse current detection control circuit, the signal isolation circuit and the power supply voltage control circuit is exemplarily described below with reference to the accompanying drawings:

fig. 11 is a schematic block diagram of a headset structure of an embodiment of the invention, where solid lines in fig. 11 may represent electrical connections and dashed lines may represent communication connections. Specifically, the connection relationship of the earphone including various circuits or modules may be embodied as: the microphone end of the earphone is electrically connected to the first voltage detection control circuit 705 through the voltage protection circuit 701, the reverse current detection control circuit 702, the signal isolation circuit 703 and the energy storage circuit 704 in sequence, and is electrically connected to the signal processing circuit 710, the sound pickup circuit 709 and the biometric feature detection module 711 respectively through the first voltage detection control circuit 705. Taking the connection between the signal processing circuit 710 and the first voltage detection control circuit 705 as an example, the connection of the first voltage detection control circuit 705 to the signal processing circuit 710 by a solid line may be understood as the first voltage detection control circuit 705 being electrically connected to the signal processing circuit 710. The first voltage detection control circuit 705 is bi-directionally coupled to the signal processing circuit 710 via a dashed line to understand that the first voltage detection control circuit 705 and the signal processing circuit 710 can be in bi-directional communication. In practical operation, the signal processing circuit 710 can control the connection between the first voltage detection control circuit 705 and the signal processing circuit 710 by sending a control signal to the first voltage detection control circuit 705. Similarly, as shown in fig. 11, the power supply circuit 707 may be communicatively connected to the microphone end of the headset and the signal processing circuit 710, the sound pickup circuit 709 may be communicatively connected to the microphone end of the headset, the biometric detection module 711 and the biometric display module 712 may be communicatively connected to the signal processing circuit 710, respectively, and the biometric detection module 711 may also be communicatively connected to the microphone end of the headset through the communication circuit 706.

It should be understood that the connection relationship of the various modules or circuits in the earphone shown in fig. 11 is only an example, and in other embodiments, the earphone may include some of the circuits or modules shown in fig. 11, for example, the reverse current detection control circuit 702 or the first voltage detection control circuit 705, etc. are not included. For another example, the microphone of the earphone may also be communicatively connected to the signal processing circuit 710 through the voltage protection circuit 701, that is, the signal processing circuit 710 controls the operation mode (e.g., on or off) of the voltage protection circuit 701.

For the voltage control of the microphone end of the earphone, a voltage protection circuit 701 and a power supply circuit 707 are introduced in the present embodiment. On one hand, when a relatively high voltage (for example, 5V) is output for a terminal device (for example, a mobile phone) paired with a headset, the voltage protection circuit 701 in the embodiment of the present invention may be used to prevent a circuit at the back end from being damaged by an excessively high voltage. Taking the terminal device as a mobile phone as an example, a 3.5mm earphone port of the mobile phone can be used as a connector in this embodiment. A Microphone (MIC) power supply pin in the earphone port of the mobile phone can be used for supplying power to the whole earphone and transmitting data to the mobile phone by the earphone, and a right sound channel (R) of the mobile phone can be used as a port for sending instructions to the earphone by the mobile phone. The voltage protection circuit 701 in this embodiment may be provided with a threshold voltage, the voltage protection circuit 701 outputs the threshold voltage when the input voltage (i.e., the output voltage of the power supply terminal of the terminal device) of the voltage protection circuit 701 is higher than the threshold voltage, and the output voltage of the voltage protection circuit 701 is the same as the input voltage when the input voltage is higher than the threshold voltage. Namely, the voltage protection circuit 701 is used for limiting the output voltage of the power supply terminal of the mobile phone. For example, if the maximum operating voltage of the earphone is 3V and the output voltage of the power supply terminal of the mobile phone is 5V, the earphone may be damaged. In this embodiment, the threshold voltage of the voltage protection circuit 701 is set to be 2.8V, and when the power supply terminal of the mobile phone outputs 5V, the maximum voltage of the earphone is 2.8V under the limitation of the voltage protection circuit 701, so as to protect the earphone circuit. If the output voltage of the power supply terminal of the mobile phone is lower than 2.8V, the voltage provided by the voltage protection circuit 701 to the subsequent circuit is the output voltage of the power supply terminal of the mobile phone.

On the other hand, when the output voltage of the power supply terminal for the terminal device is too low, the power-taking circuit 707 in this embodiment may send a third signal to the terminal device into which the earphone is inserted, where the third signal is used to excite the terminal device to increase the voltage output by the power supply terminal. In an alternative embodiment, the power-taking circuit 707 may be configured to transmit a signal to the terminal device (for example, to pull down a voltage at a microphone of the mobile phone), where the signal is used to trigger a power supply terminal of the terminal device to output a high voltage. Taking a terminal device as a mobile phone as an example, for example, when the voltage at the microphone end of the mobile phone shown in fig. 12 is too low, the power-taking circuit 707 may pull down the voltage at the microphone end of the mobile phone and maintain the voltage for a period of time (T ms shown in fig. 13), so as to trigger the mobile phone to improve the output capability of the microphone end of the mobile phone again. It should be noted that the sound pickup circuit 709 shown in fig. 11 can be used for receiving external sound signals, converting the external sound signals into electrical signals and transmitting the electrical signals to the terminal equipment. In an alternative embodiment, the power to the sound pickup circuit 709 may be controlled by the signal processing circuit 710 or other circuits or modules in order to save power consumption.

It should be understood that the above-mentioned case that the output voltage of the power supply terminal of the terminal equipment is too low includes, but is not limited to, the following cases: the power supply terminal of the terminal equipment (such as the voltage of the microphone end output by a 3.5mm port of the mobile phone) is unstable. When the terminal device is not using the microphone, namely, the microphone of the terminal device is dormant (the output voltage is reduced, and the internal resistance is increased). The voltage is too low when the earphone button is pressed. Taking the terminal device as a mobile phone as an example, optionally, the power supply mode of the mobile phone with a 3.5mm interface may include: at least one of a no power mode, a strong power mode, and a weak power mode. When the 3.5mm interface of the mobile phone is in the strong power supply mode, the sound pickup circuit 709 can normally work, and when the 3.5mm interface of the mobile phone is in the weak power supply mode, the sound pickup circuit 709 can not necessarily normally work. The sound pickup circuit 709 in the embodiment of the present invention may be a microphone circuit, or may be another type of module for conversation, and the embodiment of the present invention is not limited in particular. Optionally, when the handset interface is in the strong power mode, the internal level (152 shown in fig. 2) of the handset interface is generally higher than the 1.6v power supply voltage; when the mobile phone interface is in a weak power supply mode, the internal level of the mobile phone interface may be lower than 1.8 v; it should be understood that the power supply modes of different mobile phones may have certain differences. The above numbers are merely exemplary, and the embodiments of the present invention are not limited thereto. For example, when the handset interface is in a weak power mode, the internal level of the handset interface may be below 1.7 v. In actual work, when the corresponding 3.5mm interface of the mobile phone is in a strong power supply mode, sufficient power supply voltage can be provided for the earphone. However, when the handset 3.5mm interface is in a weak power mode, the headset's supply voltage is a sleep voltage (e.g., a sleep voltage that drops from 2.7v operating voltage to 1.4 v). It should be noted that: the condition that the mobile phone interface is in the strong power supply mode can comprise that: the wired earphone is plugged into the mobile phone, and the microphone related application program is opened (such as conversation); alternatively, when no microphone application is turned on, the sound pickup circuit 709 is in an idle state; for example, a period of time after the wired headset is inserted; as another example, a period of time after a key press; or for a period of time after the microphone related application has stopped being used. Correspondingly, in other time periods, the mobile phone interface is in a weak power supply mode.

For the voltage detection of the microphone end of the earphone, in this embodiment, a second voltage detection control circuit 708 is introduced, and the second voltage detection control circuit 708 is configured to detect a power supply end of the terminal device (for example, a voltage of the microphone end output by a 3.5mm port of the mobile phone), that is, a microphone end voltage of the earphone in time, and when it is detected that the microphone end voltage of the earphone is too low, the earphone can enter a corresponding working mode and perform corresponding processing, for example, enter a low power consumption mode, and perform a related action to trigger the terminal device to output a higher voltage (for example, trigger the power supply circuit 707 to work). In other words, the second voltage detection control circuit 708 is configured to measure the voltage condition at the microphone of the headset and output a signal representing the power supply voltage condition at the microphone of the mobile phone to the signal processing circuit 710, so that the signal processing circuit can make the headset enter a corresponding operating mode according to the signal and perform corresponding processing. Taking the sound pickup circuit 709 as an example, the second voltage detection control circuit 708 may generate and send a fourth signal to the signal processing circuit 710, where the fourth signal is used to indicate a voltage condition of a microphone of an earphone, and the signal processing circuit 710 may control the power taking circuit 709 based on the fourth signal after receiving the fourth signal.

Taking the terminal device as a mobile phone as an example, the power supply model of the power supply end of the mobile phone in this embodiment may be a voltage source + a resistor, that is, the power supply end of the mobile phone may provide a power supply and may receive a signal. Therefore, the energy storage circuit 704 in the embodiment of the present invention may store a weak current output by the power supply terminal of the mobile phone, and start a subsequent circuit to operate when sufficient charge is stored.

In connection with the energy storage circuit 704, on one hand, a reverse current detection control circuit 702 is introduced in the embodiment of the present invention, which can be used to control the flowing direction of the current, specifically, to provide power to the system when the output voltage of the power supply terminal of the mobile phone is high, and to prevent the charge loss of the energy storage circuit 704 when the output voltage of the power supply terminal of the mobile phone is low. In other words, the reverse current detection control circuit 702 in this embodiment can be used to limit the unidirectional current flow, i.e., only allow the current to flow from the power supply terminal of the mobile phone to the following circuit, and prevent the current from flowing from the following circuit to the power supply terminal of the mobile phone.

On the other hand, the embodiment of the present invention introduces the first voltage detection control circuit 705, which may be configured to detect the voltage of the tank circuit, and specifically, when the first voltage detection control circuit 705 detects that the voltage on the tank circuit 704 reaches the voltage at which the system normally operates, power is supplied to each module or circuit in the headset through the voltage at the microphone end of the headset and the charge stored in the tank circuit 704. When the first voltage detection control circuit 705 detects that the voltage on the tank circuit 704 is too low, a power-off voltage signal is sent to the earphone or a part of modules or circuits in the earphone to remind that the system voltage is not enough for the system to perform corresponding processing (such as entering a low power consumption mode), or the power supply voltage of a part of modules or circuits in the earphone is controlled. In other words, the first voltage detection control circuit 705 can be used to detect the charge voltage of the tank circuit 704, and when the storage voltage of the tank circuit 704 reaches a certain threshold, the first voltage detection control circuit can provide power to the subsequent circuit of the tank circuit 704, and further, can output a signal to the signal processing circuit 710, wherein the signal indicates how much charge is stored in the tank circuit 704.

In addition, in practical communication, for devices (such as a MIC output line of a mobile phone) transmitting signals through a power line, it is necessary to avoid attenuation of signals to be transmitted on the power line, and it is also necessary to avoid interference of power supply fluctuation generated by the operation of an earphone with signals on the power line. The signal isolation circuit 703 in the embodiment of the present invention can isolate these two signals, i.e. can prevent the signal output by the isolated audio pick-up circuit 709 (the signal is converted from audio and transmitted to the mobile phone) from being attenuated, and can prevent the output signal of the audio pick-up circuit 709 from being affected by the power supply fluctuation caused by the operation of the circuit behind the signal isolation circuit 703.

Taking a terminal device as a mobile phone as an example, the communication circuit 706 in this embodiment is responsible for the communication function between the mobile phone and the earphone. The communication circuit 706 collects data (heart rate value, system status, etc.) of the signal processing circuit 710 and data (heart rate raw data, etc.) of the biometric detection module 711, and transmits the data to the mobile phone through the MIC power supply of the mobile phone. Meanwhile, the data sent by the mobile phone end (transmitted to the communication circuit 706 through the right channel line of the mobile phone) is correspondingly sent to the signal processing circuit 710 and the biometric feature detection module 711. Optionally, the communication circuit 706 may further include a key signal, and the key signal is sent to the mobile phone. The signal processing circuit 710 may be a control center of the whole headset, and in particular, the signal processing circuit 710 may be used to read the raw heart rate data of the biometric detection module 711 and to calculate the heart rate value. The signal processing circuit 710 may also be configured to control the biometric display module 712 to display the value of the biometric characteristic or the range in which the biometric characteristic is located. The signal processing circuit 710 can also be used to control the power supply of the first voltage detection control circuit 705. The signal processing circuit 710 may also be used for data exchange with the communication circuit 706. The signal processing circuit 710 may also be configured to receive the output signal of the second voltage detection control circuit 708 and determine the voltage condition at the microphone of the earphone. The signal processing circuit 710 may also be configured to control the power-taking circuit 707 to operate, and trigger the microphone of the mobile phone to output a high voltage. In addition, the biometric detection module 711 may be placed near the skin of the user to obtain the original heart rate data of the user, and the biometric display module 712 may display the value of the displayed biometric of the current user or the interval in which the biometric is located.

In practical operation, taking a terminal device as a mobile phone as an example, a workflow of an earphone may include: when the earphone is inserted into the earphone hole of 3.5mm at the mobile phone end, the power supply end of the mobile phone outputs voltage, and the voltage protection circuit 701 is used for limiting the output voltage of the mobile phone and preventing the output voltage of the mobile phone from being too high and damaging the rear end circuit. Since the entire headset is inserted for the first time, no charge is stored in the tank circuit 704, and current flows through the voltage protection circuit 701, the reverse current detection control circuit 702 and the signal isolation circuit 703 into the tank circuit 704 for storage. When the first voltage detection control circuit 705 detects that the voltage of the tank circuit 704 reaches a threshold voltage (e.g., 2V), the tank circuit 704 supplies power to modules or circuits at the back end of the tank circuit 704, such as the signal processing circuit 710, the sound pickup circuit 709, and the biometric feature detection module 711. After the modules or circuits at the back end of the tank circuit 704 are powered, normal operation is started. Further, after the signal processing circuit 710 obtains power, it controls the biometric feature detection module 711 and obtains corresponding heart rate raw data, and performs the operation of the heart rate signal, and displays the heart rate signal through the biometric feature display module 712.

When a key is pressed, the communication circuit 706 generates a key signal to pull down the power supply voltage of the microphone of the mobile phone. In one aspect, the second voltage detection control circuit 708 sends a low voltage signal at the power supply voltage of the microphone of the mobile phone to the signal processing circuit 710, and the signal processing circuit 710 performs corresponding processing to save power consumption, such as stopping the biometric detection and display, and turning off the power supply of the sound pickup circuit 709. On the other hand, when a key signal is generated, the power supply voltage of the microphone of the mobile phone is lower than the voltage of the energy storage circuit 704, and the reverse current detection control circuit 702 will disconnect the path to prevent the charge of the energy storage circuit 704 from flowing back to the microphone of the mobile phone. When the microphone is used in the mobile phone system, the sound pickup circuit 709 converts the sound signal into an electrical signal, and transmits the electrical signal to the output terminal of the voltage protection circuit 701, so as to transmit the electrical signal to the microphone terminal of the mobile phone. The output signal of the sound pickup circuit 709 is not attenuated due to the presence of the backflow detection control circuit 702 and the signal isolation circuit 703. Meanwhile, power supply fluctuation generated when the headset works cannot be transmitted to the microphone end of the mobile phone due to the existence of the signal isolation circuit 703. It should be noted that, for some mobile phones, when the microphone is not used in the mobile phone system, the microphone end may sleep, which is reflected in that the output voltage becomes low, the internal resistance increases, and the power supply capability becomes weak. At this point, on the one hand, the backflow detection control circuit 702 may be used to prevent the charge of the tank circuit 704 from flowing to the microphone of the handset. On the other hand, the second voltage detection control circuit 708 detects the signal and sends the signal to the signal processing circuit 710, the signal processing circuit 710 detects that the microphone of the mobile phone is in power supply sleep, and then sends a power-taking signal to the power-taking circuit 707, and the power-taking circuit 707 triggers the mobile phone to enable the voltage output by the microphone of the mobile phone to be high voltage.

In summary, in the embodiment of the present invention, by introducing the power-taking circuit 707, the second voltage detection control circuit 708, the reverse current detection control circuit 702, and the first voltage detection control circuit 705, when the voltage at the microphone end of the earphone is too low, the power-taking circuit 707 may excite the terminal device to increase the voltage output by the power supply end. In addition, the signal processing circuit 710 can make the earphone enter a corresponding working mode and perform corresponding processing according to the voltage condition of the microphone end of the earphone measured by the second voltage detection control circuit 708 and/or the charge condition of the energy storage circuit measured by the first voltage detection control circuit 705, so as to reasonably distribute power to each module or circuit in the earphone. In addition, the countercurrent detection control circuit 702 can effectively prevent the charge in the energy storage circuit from losing to the power supply end of the mobile phone, and avoid the waste of the charge in the energy storage circuit. Finally, the signal isolation circuit 703 can effectively reduce the interference between the sound pickup circuit 709 and the back-end circuit.

It should be understood that the signal processing circuit 710 shown in fig. 11 may control the power supply voltage of the signal processing circuit 710 and other circuits or modules (e.g., the power supply circuit 707, the biometric detection module 711, and the biometric display module 712) in the headset according to the detection result of the module or circuit (e.g., the second voltage detection control circuit 708 and/or the first voltage detection control circuit 705) in the headset. The Signal Processing circuit 710 may be a Micro Controller Unit (MCU) or a Digital Signal Processing (DSP) circuit for controlling power supply, operation mode, and data of each module or circuit in the headset, and more particularly, for controlling operation mode (i.e., power consumption) of each circuit or module in the wired headset according to actual requirements. The voltage protection circuit 701 of the embodiment of the present invention is used for controlling the output voltage through the microphone terminal of the earphone and the power supply terminal of the terminal device, that is, controlling the input voltage of the earphone. It should be understood that the calculation control module 210 shown in fig. 3 is used to control the power supply, the operation mode, and the calculation and indication of the measured heart rate results of the acquisition module 220 as exemplary descriptions. However, the present invention is not limited thereto. For example, in other embodiments, the calculation control module 210 may also be integrally disposed on the signal processing circuit 710, that is, the acquisition module 220 may be designed separately, so that after the acquisition module 220 acquires data, the acquired data may be sent to the signal processing circuit 710, and the signal processing circuit 710 controls the power supply, the operation mode, and the calculation and indication of the measured heart rate result of the acquisition module 220.

It should be further understood that each circuit or module shown in fig. 11 may be produced as a control device or a circuit of the earphone alone, may also be produced as a control device partially integrated into the earphone, and may also be produced as an overall control device of the earphone fully integrated onto one workpiece, and the embodiment of the present invention is not limited in particular. For example, the voltage protection circuit 701 may be manufactured as a component of a wired headset, or may be manufactured integrated with the signal processing circuit 710, i.e., as an integral part of the signal processing circuit 710. In connection with fig. 6, the circuits or modules shown in fig. 11 may be disposed separately or integrally in the line control board of the wired headset, or disposed separately or integrally on the earplugs (the right earpiece 340a and the left earpiece 340 b). In other embodiments, each circuit or module shown in fig. 11 can be split into a plurality of modules or circuits respectively disposed on the wire control board 330, the left ear plug 340b and the right ear plug 340 a. The embodiment of the present invention is not particularly limited. Furthermore, each module or circuit related to the embodiment of the present invention may be embedded in any wired earphone, and the wired earphone is used in cooperation with the intelligent terminal. Especially possess the intelligent terminal of 3.5mm audio output interface. For example: mobile phones, tablet computers, notebook computers, MP3, MP4, and the like. The embodiment of the present invention is only exemplified in a scenario where the control device is built in the wired headset, and the wired headset and the mobile phone are used in a matching manner, but the embodiment of the present invention is not limited thereto.

Fig. 14 is an exemplary diagram of one circuit design of a headset of an embodiment of the present invention. Fig. 15 is a diagram of an example of the first voltage detection control circuit 705 of fig. 11. Fig. 16 is another example diagram of the first voltage detection control circuit 705 of fig. 11. Fig. 17 is an exemplary diagram of another circuit design for a headset of an embodiment of the present invention. The various circuits and modules described above are illustrated below with reference to specific circuit designs.

With respect to the specific circuit configuration of the backflow detection control circuit 702 shown in fig. 11:

in one example, as shown in fig. 14, the backflow detection control circuit 702 may include: resistor 813, resistor 814, resistor 819, resistor 815, switch 817, diode 818, comparator 820, and not-gate 816. Specifically, taking the terminal device as a mobile phone as an example, when a current flows from a microphone terminal of the mobile phone to a subsequent circuit (such as the capacitor 821 and the capacitor 822), a voltage at a reverse terminal of the comparator 820 is higher than a voltage at a same phase terminal, an output of the comparator 820 is a low level, and after passing through the not gate 816, the switch 817 is controlled to be closed. Here, diode 818 provides a path for current flow. When the current flows from the rear end to the microphone end of the mobile phone, the voltage of the in-phase end of the comparator 820 is higher than that of the anti-phase end, the output of the comparator 820 is at a high level, and the switch 817 is controlled to be switched off through the not gate 816. The diode 818 is now in the reverse cutoff state, which prevents charge loss from the energy storage module. In other words, when the button 802 is pressed, the voltage at the earphone microphone becomes low, and the charge flows from the storage capacitor 822, through the resistor 823, the switch 817, the resistor 814, the LDO 804, the resistor 801, and the button 802 to the ground. The current flowing through resistor 814 causes the voltage at the non-inverting terminal of comparator 820 to be higher than the voltage at the inverting terminal. The comparator 820 output is high and switch 817 is open. Due to the existence of the feedback resistor 815, when the comparator 820 outputs a high level voltage, the same-phase terminal voltage of the comparator can be ensured to be always larger than the reverse-phase terminal voltage, and the switch 817 is ensured to be always in an off state.

In yet another example, as shown in fig. 17, the backflow detection control circuit 702 may include: MOS pipe 917, comparator 920 and resistor 919; the microphone terminal is connected to the tank circuit 704 through the MOS tube 917; the negative input terminal of the comparator 920 is connected to the microphone terminal of the earphone, the positive input terminal of the comparator 920 is connected to the tank circuit 704, and the output terminal of the comparator 920 is connected to the gate of the MOS transistor 917 via the resistor 919. Further, in order to improve the performance of the current detection control circuit 702, that is, to improve the effect of preventing the charges in the tank circuit from flowing to the power supply terminal of the terminal device, the reverse current detection control circuit 702 may further include: MOS transistor 916 and resistor 918; the drain of MOS transistor 917 is connected to the drain of MOS transistor 916; the comparator 920 is connected to the gate of the MOS transistor 916 through the resistor 918. Further, to improve the performance of the flow detection control circuit 702, the reverse flow detection control circuit 702 may further include: a third resistor (not shown); the MOS transistor 917 is connected to the MOS transistor 916 through the third resistor. In actual operation, when the voltage at the microphone of the earphone is higher than the voltage of the capacitor 923, the output of the comparator 920 is at a low level, the MOS transistor 916 and the MOS transistor 917 are turned on, and a current flows from the microphone of the earphone to the capacitor 923 and the capacitor 924. When the output voltage of the microphone of the earphone is lower than the voltage of the capacitor 923, the output of the comparator 920 is at a high level. The MOS transistor 917 and the MOS transistor 916 are turned off to prevent the charges from flowing from the capacitor 923 and the capacitor 924 to the microphone of the earphone. Further, in order to increase the voltage difference between the non-inverting terminal and the inverting terminal of the first comparator 920, a resistor may be connected in series between the MOS transistor 917 and the MOS transistor 916, and the current flowing through the MOS transistor 917 and the MOS transistor 916 may also flow through the resistor.

For the specific circuit structure of the signal isolation circuit 703 shown in fig. 11:

in one example, as shown in fig. 14, the signal isolation circuit 703 may include: a resistor 814, a resistor 823, a capacitor 821, and a capacitor 822; the sound pickup circuit 709 is connected to one end of the resistor 814, the other end of the resistor 814 is connected to ground through the capacitor 821, the other end of the resistor 814 is further connected to one end of the capacitor 822 through the resistor 823, and the other end of the capacitor 822 is grounded. The resistor 814 and the capacitor 821 isolate the sound signal output by the Microphone (MIC)806, and prevent the sound signal output by the MIC 806 from being excessively attenuated and interfering with the operation of a later-stage circuit; the resistor 823, the capacitor 821 and the capacitor 822 are used for filtering power noise generated by system operation to interfere with a previous stage circuit. In a possible implementation, the capacitor 821 and/or the capacitor 822 may constitute a tank circuit 704 of the headset for storing a weak current to the microphone of the headset and for supplying other circuits or modules.

In yet another example, as shown in fig. 17, the signal isolation circuit 703 may include: a low dropout linear regulator (LDO)921, a resistor 922, a capacitor 923, and a capacitor 924; the mic terminal is connected to the input terminal of the reverse current detection control circuit 702 through the voltage control circuit 701, the output terminal of the reverse current detection control circuit is connected to one end of the LDO 921, the other end of the LDO 921 is connected to ground through the capacitor 923, the other end of the LDO 921 is also connected to one end of the capacitor 924 through the resistor 922, and the other end of the capacitor 924 is connected to ground. Specifically, the LDO 921 may be used to prevent the signal output by the MIC 909 from decaying. The principle is that if the output voltage of LDO 921 is set to be low (e.g. 2V), when the input power of LDO 921 is higher than 2V, the output will not be affected even if the input power fluctuates. In a possible implementation, the capacitor 923 and/or the capacitor 924 may constitute the tank circuit 704 of the headset.

With respect to the specific circuit configuration of the sound pickup circuit 709 shown in fig. 11:

as an example, as shown in fig. 14, the sound pickup circuit 709 may include: a capacitor 805, a microphone 806, a capacitor 807, a resistor 808, a switch 809, and a not circuit 810; the microphone end of the earphone is connected with one end of the capacitor 805, the other end of the capacitor 805 is connected with one end of the capacitor 807 through the microphone 806, one end of the capacitor 807 is connected to one end of the switch 809 through the resistor 808, the other end of the switch 809 is connected with the microphone end of the earphone, and the other end of the capacitor 807 is grounded; the signal processing circuit 710 of the earphone is used for controlling the switch 809 to be turned on or off. In other words, the sound pickup circuit 709 may be constituted by the capacitor 805, the microphone 806, the capacitor 807, the resistor 808, the switch 809, and the not circuit 810. In this embodiment, the signal processing circuit 710 may be an MCU 933, and the MCU 933 powered by the sound pickup circuit 709 is implemented by a control switch 809. The microphone 806 converts the sound into an electrical signal, which is transmitted to the handset microphone power supply via the capacitor 805.

With respect to the specific circuit configuration of the second voltage detection control circuit 708 shown in fig. 11:

as one example, as shown in fig. 14, the second voltage detection control circuit may include: resistor 811 and resistor 812; taking the MCU 833 as the example of the signal processing circuit 710, the microphone of the earphone is connected to one end of the resistor 812 through the resistor 811, the microphone of the earphone is connected to the signal processing circuit 710 through the resistor 811, and the other end of the resistor 812 is grounded. In this embodiment, a voltage division value may be obtained by dividing the voltage through the resistor 811 and the resistor 812, and the voltage division value may be input into the MCU 833 for detection by a module such as an Analog-to-Digital Converter (ADC) in the MCU 833, where the MCU 833 may provide a signal processing function.

Further, the connection relationship between the signal processing circuit 710 and the first voltage detection control circuit 705 shown in fig. 11 is referred to. As an example, as shown in fig. 14, taking the signal processing circuit 710 as an MCU 833 as an example, an output terminal of the first voltage detection control circuit 824 is connected to a first input terminal of the or circuit 825, and the first voltage detection control circuit 824 is configured to generate and send first information to the or circuit 825, where the first information is used to indicate a tank condition of the tank circuit 703. The microphone end of the earphone is connected to one end of the MCU 833 through the second voltage detection control circuit (not labeled), the other end of the second voltage detection control circuit is connected to the second input end of the or circuit 825, the MCU 833 is configured to generate and send a second signal to the or circuit 825, and the second signal is used to indicate whether the signal processing circuit is powered. In practice, since OR circuit 825 is a dual-input OR gate, one of the characteristics of an OR gate is high or high. Therefore, when the first voltage detection control circuit 824 detects that the voltage of the tank circuit 703 reaches the threshold voltage, the first voltage detection control circuit 824 outputs a high level, and the or circuit 825 also outputs a high level. In addition, when MCU 833 is powered on, MCU 833 outputs a high level to or circuit 825, and or circuit 825 also outputs a high level, so that when first voltage detection control circuit 824 outputs a low level, it is ensured that circuit 825 outputs a high level, preventing accidental and frequent power-off of MCU 833 etc. Meanwhile, the first voltage detection control circuit 824 may also send energy storage condition information of the energy storage circuit to the MCU 833, and optionally, when the output of the first voltage detection control circuit 824 is a low level, it may indicate that the voltage of the energy storage circuit is insufficient, and then the MCU 833 may perform corresponding operations to reduce the overall power consumption.

It is to be noted that the first voltage detection control circuit 824 shown in fig. 14 may be configured with a hysteresis voltage detection function. For example, the output is high when the voltage on the tank circuit 704 reaches 2V, and is low until the tank circuit 704 voltage drops to 1.85V. In actual operation, when the output of the first voltage detection control circuit 824 is at a high level, the or circuit 825 also outputs a high level, so that the switch 826 is closed to supply power to the MCU 833, and meanwhile, an output pin of the MCU 833 may be connected to another input terminal of the or circuit 825, that is, the MCU 833 outputs a high level to the input terminal of the or circuit 825 after being powered on, and may also be used to maintain normal power supply of the MCU 833, so that the MCU 833 can be powered on as long as any one of the outputs of the first voltage detection control circuit 824 and the MCU 833 is at a high level. Further, the MCU 833 can control the power of the biometric detection module 830 by controlling the on/off of the switch 828, and the MCU 833 can also be used to calculate the current biometric value (such as heart rate value) of the user and display the value through the LED 832. When the MCU 833 calculates the value of the biometric feature, if the power consumption of the system is too large, the voltage on the energy storage capacitor 822 is lower than 1.85V, the output of the first voltage detection control circuit 824 is at a low level, and the MCU 833 obtains the signal, and then takes a corresponding measure (for example, stop the heart rate acquisition and calculation, and enter the sleep mode), so as to reduce the power consumption of the system.

With respect to the specific circuit configuration of the first voltage detection control circuit 705 shown in fig. 11:

as an example, as shown in fig. 15, the first voltage detection control circuit 824 may include: a resistor 401, a resistor 402, a resistor 403, a comparator 404, a comparator 405, and a flip-flop 406; one end of the resistor 401 is connected to the tank circuit 704, the other end of the resistor 401 is connected to one end of the resistor 403 through the resistor 402, the other end of the resistor 403 is grounded, the other end of the resistor 401 is connected to the negative input terminal of the comparator 404, one end of the resistor 402 is connected to the positive input terminal of the comparator 405, the positive input terminal of the comparator 404 and the negative input terminal of the comparator 405 receive a reference voltage, the output terminal of the comparator 404 is connected to the R input terminal of the flip-flop 406, and the output terminal of the comparator 405 is connected to the S input terminal of the flip-flop 406. In other words, the resistor 401, the resistor 402 and the resistor 403 are connected in series, the resistor 401 is connected with the measured voltage, and the resistor 403 is connected with the ground and divides the measured voltage (Vi); the non-inverting input of the comparator 404 is connected with the reference voltage, the inverting input is connected with the intersection of the resistor 401 and the resistor 402, and the output of the comparator 404 is connected with the R end of the trigger 406. The non-inverting input terminal of the comparator 405 is connected to the intersection of the resistor 401 and the resistor 402, the inverting input terminal of the comparator 405 is connected to the reference voltage, and the output terminal is connected to the S terminal of the flip-flop 406; the Q of the flip-flop 406 is used as a signal for voltage detection.

Output state equation from flip-flop 406

It can be seen that when the voltage (Vi) is too low, the voltage at the inverting input of the comparator 404 is lower than the reference voltage. At this time, the output of the comparator 404 is high, the output of the comparator 405 is low, and the output of the Q terminal of the flip-flop 406 is low. When the Vi voltage gradually increases, so that the voltage at the inverting input terminal of the comparator 404 is higher than the reference voltage, but the voltage at the non-inverting input terminal of the comparator 405 is lower than the reference voltage, at this time, the output of the comparator 404 is at a low level, the output of the comparator 405 is at a low level, and the output of the Q terminal of the flip-flop 406 is at a low level. When the voltage Vi rises again, so that the voltage at the inverting input terminal of the comparator 404 is higher than the reference voltage, and the non-inverting input terminal of the comparator 405 is higher than the reference voltage, the output of the comparator 404 is at a low level, and the output of the comparator 405 is at a high level, and the output of the Q terminal of the flip-flop 406 is at a high level. If the measured voltage is reduced to a level where the voltage at the inverting input of comparator 404 is greater than the reference voltage, but the voltage at the non-inverting input of comparator 405 is less than the reference voltage. At this time, although the output of the comparator 404 is low and the output of the comparator 405 is low, the previous state of the Q terminal of the flip-flop 406 is high, and thus the current state of the Q terminal of the flip-flop 406 is also high. The voltage to be measured continues to decrease until the voltage at the reverse input terminal of the comparator 404 is lower than the reference voltage, and the voltage at the non-inverting input terminal of the comparator 405 is lower than the reference voltage, then the output of the comparator 404 is high level, and the output of the comparator 405 is low level. The output of the Q terminal of the current flip-flop 406 is low. This enables detection of the hysteresis voltage. In this embodiment, the resistance 40 is adjusted1. The ratio of

resistors

402 and 403 may also adjust the detection range of the hysteresis voltage.

As still another example, as shown in fig. 16, the first voltage detection control circuit 824 may include: a resistor 407, a resistor 409, a resistor 408 and a comparator 411; the tank circuit 704 is connected to one end of the resistor 409 through the resistor 407, the other end of the resistor 409 is connected to the output end of the comparator 411, the negative input end of the comparator 411 receives a reference voltage, and the positive input end of the comparator 411 is connected to the ground through the resistor 408. In other words, the resistor 407 connects the voltage to be measured to the non-inverting input terminal of the comparator 411, the resistor 409 connects the output terminal and the non-inverting input terminal of the comparator 411, the resistor 408 connects the non-inverting input terminal of the comparator 411 to ground, and the inverting input terminal of the comparator 411 is connected to the reference voltage. In actual operation, when the measured voltage is low enough that the voltage at the non-inverting input terminal of the comparator 411 is lower than the reference voltage, the output of the comparator 411 is at a low level. When the measured voltage rises, the voltage at the non-inverting input terminal of the comparator 411 is the divided voltage of the total resistance value of the resistor 408 and the resistor 409 which are connected in parallel and the resistor 407. When the voltage rises until the voltage at the non-inverting input terminal of the comparator 411 is higher than the reference voltage, the output of the comparator 411 is at a high level, and at this moment, the calculation model of the voltage at the non-inverting input terminal of the comparator 411 is changed. When the voltage drops by a certain value so that the voltage at the non-inverting input terminal of the comparator 411 is lower than the reference voltage value, the comparator 411 outputs a low level again. It can be seen that the voltage calculation model of the non-inverting input terminal of the comparator 411 from high output to low output is different from that of the comparator 411 from low output to high output, so that the voltage threshold of the two voltage measurement terminals are different. In other words, the comparator 411 outputs a threshold value from a low level to a high level that is greater than a threshold value from a high level to a low level, so that the first voltage detection control circuit 705 realizes the hysteresis voltage detection.

For the specific circuit structure of the power-taking circuit 707 shown in fig. 11:

as an example, as shown in fig. 14, the power-taking circuit 707 may include: a switch 803; the microphone terminal is connected to ground through the switch 803. Taking the terminal device as a mobile phone as an example, when a microphone is not used in a mobile phone system, the microphone end of the mobile phone is dormant, which means that the output voltage of the microphone end of the mobile phone becomes low and the power supply capability becomes weak. The output voltage at the handset microphone becomes low (lower than the voltage of the storage capacitor 822), causing charge to flow from the storage capacitor 822 back to the handset microphone. At this point, the comparator 820 output is high, which in turn controls switch 817 to open. Meanwhile, taking the signal processing circuit 710 as the MCU 833 for example, the MCU 833 will trigger the mobile phone to output a high voltage by controlling the switch 803 when the second voltage detection control circuit (the resistor 811 and the resistor 812) detects that the microphone of the mobile phone is in a sleep state. Alternatively, the triggering mode may be to pull down the voltage of the microphone of the handset for 25ms after the microphone of the handset is dormant for 40 ms.

For the specific electrical connection structure of the voltage protection circuit 701 shown in fig. 11:

as an example, as shown in fig. 14, the voltage protection circuit may be a low dropout linear regulator (LDO) 804. In other words, taking the terminal device as a mobile phone as an example, when the earphone is connected to the mobile phone through the 3.5mm interface, the mobile phone outputs a high voltage, and the LDO 804 can prevent the mobile phone from damaging the subsequent circuit when outputting a 5V voltage.

As another example, as shown in fig. 17, the voltage protection circuit 701 may include: a Metal Oxide Semiconductor (MOS) transistor 903, a comparator 907, and a resistor 906; the microphone end is connected with the MOS tube 903; the negative input terminal of the comparator 907 receives a threshold voltage, the positive input terminal of the comparator 907 is connected to the microphone terminal of the earphone, and the output terminal of the comparator 907 is connected to the gate of the MOS transistor 903 through the resistor 906. Further, as shown in fig. 17, the voltage protection circuit further includes: a MOS transistor 904 and a resistor 905; the drain of the MOS transistor 904 is connected to the drain of the MOS transistor 903; the output terminal of the comparator 907 is connected to the gate of the MOS tube 903 through the resistor 905. Specifically, taking the terminal device as a mobile phone as an example, when the voltage at the microphone of the earphone is higher than the threshold voltage (Vref), the output of the comparator 907 is high, the MOS 903 and the MOS 904 are turned off, and when the voltage at the microphone of the earphone is lower than Vref, the output of the comparator 907 is low, and the MOS 903 and the fourth MOS are turned on. More specifically, assume that Vref is set to 2.8V. When the output voltage of the microphone end of the mobile phone is higher than 2.8V, the MOS tube 903 and the MOS tube 904 are cut off to prevent the excessive voltage from damaging the rear-stage circuit. When the voltage of the power supply terminal of the mobile phone microphone is lower than 2.8V, the MOS tube 903 and the MOS tube 904 are conducted to supply charges to a later stage circuit.

As shown in fig. 14, taking the signal processing circuit 710 as an example of the MCU 833, the energy storage circuit 704 of the earphone can be further connected to the biometric feature detection module 830 of the earphone through a switch 828, and the MCU 833 is used to control the switch 828 to turn on or off. In other words, the power supply of the biometric detection module 830 is controlled by the MCU 833. Taking the terminal device as a mobile phone as an example, when the mobile phone needs to send a command to the headset, only a specific waveform needs to be sent on the right channel. The MCU 833 and the biometric detection module 830 receive the instruction, so that the MCU 833 can stop the calculation and display of the biometric features, and the biometric detection module 830 sends the data to the mobile phone through the microphone, so as to calculate and display the biometric features on the mobile phone. Further, as shown in fig. 14, the biometric detection module may communicate with the MCU 833 in both directions through an Inter Integrated Circuit (IIC)/Serial Peripheral Interface (SPI). As shown in fig. 14, as an example, the capacitor 822 in the energy storage circuit may be further connected to one end of a low dropout linear regulator (LDO)827, the other end of the LDO 827 may be further connected to ground through a capacitor 829, the other end of the LDO 827 may be further connected to the biometric detection module 830 through the switch 828, and further, the other end of the LDO 827 may be further connected to ground through a capacitor 831, thereby increasing the operation performance of the circuit.

It should be understood that the connection relationships between the modules or circuits shown in fig. 14 to 17 and the specific circuit structures of the modules or circuits are only exemplary descriptions, and in order to avoid repetition, the parts having the same circuit structures in fig. 14 and 17 are not repeated (for example, the power taking circuit, the second voltage detection control circuit, and the communication circuit).

In the embodiment of the invention, the traditional wired earphone is provided with a function of detecting the biological characteristics (such as the heart rate) by adding the biological characteristic detection module to the traditional wired earphone with the 3.5mm audio interface. In addition, the detection result can be displayed in real time by adding the biological characteristic display module. As one example, the biometric display module includes a plurality of light emitting diodes, LEDs. As shown in fig. 11, the headset may also include a biometric display module 712. Further, as shown in fig. 14, the biometric display module may indicate the value of the biometric feature through a Light-Emitting Diode (LED) 832 or an Organic Light-Emitting Diode (OLED) or other visualization devices, taking the heart rate intensity as an example, for example: several different colored LEDs may be used to indicate different heart rate intensity intervals. For example, a blue LED may be used to represent a heart rate between 30BPM and 80 BPM; wherein the green LED represents the heart rate of 80-110 BPM; red represents between 110 and 150 BPM; yellow represents 150-180 BPM; orange is used for representing that the heart rate interval is between 180 and 220 BPM. It should be understood that the above-mentioned heart rate intensity intervals and indication manners are only examples of the embodiments of the present invention, and the embodiments of the present invention are not limited thereto. For example, the biometric display module 712 may display a color and may also indicate the heart rate in cooperation with different flashing frequencies. For example, the higher the heart rate LED blink frequency, the higher the heart rate correspondingly. For another example, the biometric display module 712 may also use an LED to indicate the heart rate interval by different flashing speeds.

The earphone in the embodiment of the invention does not need a battery, so that the earphone does not need to be charged and does not need to carry a charging cable or a charger. And the earphone is convenient to use, and can be used after being inserted into target equipment (such as a mobile phone), so that the production cost of the earphone is reduced. Furthermore, the earphone in the embodiment of the invention can support the earphone to complete heart rate measurement and indicate the heart rate interval, and further, a storage circuit is arranged in the earphone and used for storing the charge from the microphone end of the earphone. Therefore, even if the power supply capacity at the earphone plug of the terminal equipment is insufficient, the energy storage circuit can supply power to the earphone normally, and the phenomenon that the voltage of the power supply terminal is reduced too much when the earphone consumes large current in the moment is prevented, so that the normal voice transmission function of the earphone is influenced. Furthermore, a voltage protection circuit is arranged in the earphone, so that the circuit at the rear end can be prevented from being damaged when the voltage output by the power supply end is too large, and the normal work of the earphone is further influenced. Furthermore, a signal isolation circuit is arranged in the earphone, so that the earphone can carry out biological characteristic detection and listen to music, and a microphone is not mutually influenced. Furthermore, a reverse current detection control circuit is arranged in the earphone, so that the charge loss of an earphone energy storage circuit caused by sudden reduction of the output voltage of the mobile phone can be prevented, and the sudden power failure of the earphone is avoided. Furthermore, the power supply voltage of the signal processing module can be controlled in real time by arranging a power supply voltage control circuit in the earphone.

Those of ordinary skill in the art will appreciate that the various illustrative elements and circuits described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application. In the several embodiments provided in the present application, it should be understood that the disclosed circuits, branches and units may be implemented in other manners. For example, the above-described branch is illustrative, and for example, the division of the unit is only one logical function division, and there may be other division ways in actual implementation, for example, multiple units or components may be combined or integrated into one branch, or some features may be omitted, or not executed. The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A control device of an earphone, wherein the earphone is a wired earphone with a built-in biological feature detection module, the control device comprises:

a voltage protection circuit;

when the earphone is inserted into the terminal equipment, the voltage protection circuit is connected with a power supply end of the terminal equipment through a microphone end of the earphone, and the voltage protection circuit is used for receiving voltage output by the power supply end through the microphone end and outputting first voltage, wherein the voltage output by the power supply end is greater than or equal to the first voltage;

a power taking circuit;

the microphone end of the earphone is connected to a signal processing circuit of the earphone through the power taking circuit, the signal processing circuit is used for controlling the power taking circuit to generate and send a third signal to the terminal equipment inserted in the earphone when the voltage output by the power supply end of the terminal equipment is lower than a preset value, and the third signal is used for exciting the terminal equipment to increase the voltage output by the power supply end of the terminal equipment;

a reverse flow detection control circuit;

the microphone end of the earphone is connected to the energy storage circuit of the earphone through the countercurrent detection control circuit, and the countercurrent detection control circuit is used for comparing the voltage of the energy storage circuit with the voltage of the microphone end and controlling the electrical connection or the electrical disconnection between the energy storage circuit and the microphone end according to the comparison result.

2. The control device according to claim 1, wherein the first voltage is equal to a threshold voltage when the voltage output from the power supply terminal is higher than the threshold voltage, and the first voltage is equal to the voltage output from the power supply terminal when the voltage output from the power supply terminal is lower than the threshold voltage.

3. The control device according to claim 1, wherein the backflow detection control circuit includes:

the first MOS tube, the first comparator and the first resistor;

the microphone end is connected to the energy storage circuit through the first MOS tube;

the negative input end of the first comparator is connected with the microphone end of the earphone, the positive input end of the first comparator is connected with the energy storage circuit, and the output end of the first comparator is connected to the grid electrode of the first MOS tube through the first resistor.

4. The control device of claim 3, wherein the backflow detection control circuit further comprises:

the second MOS tube and the second resistor;

the drain electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, and the source electrode of the second MOS tube is connected with the energy storage circuit;

the output end of the first comparator is connected to the grid electrode of the second MOS tube through the second resistor.

5. The control device of claim 4, wherein the backflow detection control circuit further comprises:

a third resistor;

the first MOS tube is connected to the second MOS tube through the third resistor.

6. The control device according to any one of claims 1 to 5, characterized by further comprising:

the microphone end of the earphone is connected to one end of the signal isolation circuit through a sound pickup circuit of the earphone, and the sound pickup circuit is used for converting a received sound signal into an electric signal; the signal isolation circuit is used for isolating interference between the electric signal and a circuit connected with the other end of the signal isolation circuit.

7. The control device of claim 6, wherein the signal isolation circuit comprises:

the current limiting element, the fifth resistor, the first capacitor and the second capacitor;

the sound pickup circuit is connected with one end of the current limiting element, the other end of the current limiting element is connected to the ground through the first capacitor, the other end of the current limiting element is also connected to one end of the second capacitor through the fifth resistor, and the other end of the second capacitor is grounded;

the current limiting element is a fourth resistor or a first low dropout regulator (LDO).

8. The control device according to claim 6, wherein the sound pickup circuit comprises:

the microphone comprises a third capacitor, a microphone, a fourth capacitor, a sixth resistor, a first switch and a not circuit;

the microphone end of the earphone is connected with one end of the third capacitor, the other end of the third capacitor is connected with one end of the fourth capacitor through the microphone, one end of the fourth capacitor is connected to one end of the first switch through the sixth resistor, the other end of the first switch is connected with the microphone end, the other end of the fourth capacitor is grounded, and the NOT circuit is arranged at the control end of the first switch.

9. The control device according to any one of claims 1 to 5, characterized by further comprising:

the power supply voltage control circuit is used for controlling the power supply voltage of the signal processing circuit of the earphone;

wherein the supply voltage control circuit comprises:

a first voltage detection control circuit, an OR circuit and a second switch;

the output end of the first voltage detection control circuit is connected to the first input end of the OR circuit, and the first voltage detection control circuit is used for generating and sending a first signal to the OR circuit;

the output end of the signal processing circuit is connected with the second input end of the OR circuit, and the signal processing circuit is used for generating and sending a second signal to the OR circuit;

the energy storage circuit is connected to the signal processing circuit through the second switch;

the OR circuit is used for receiving the first signal and the second signal and controlling the second switch to be switched on or switched off according to the first signal and/or the second signal.

10. The control device according to claim 9, wherein the first voltage detection control circuit includes:

the circuit comprises a seventh resistor, an eighth resistor, a ninth resistor, a second comparator, a third comparator and a trigger;

one end of the seventh resistor is connected with the energy storage circuit, the other end of the seventh resistor is connected to one end of the ninth resistor through the eighth resistor, the other end of the ninth resistor is grounded, the other end of the seventh resistor is connected with the negative input end of the second comparator, one end of the eighth resistor is connected with the positive input end of the third comparator, the positive input end of the second comparator and the negative input end of the third comparator are connected with the reference voltage, the output end of the second comparator is connected with the R input end of the trigger, and the output end of the third comparator is connected with the S input end of the trigger;

alternatively, the first voltage detection control circuit includes:

a tenth resistor, an eleventh resistor, a twelfth resistor, and a fourth comparator;

the energy storage circuit is connected to one end of the eleventh resistor through the tenth resistor, the other end of the eleventh resistor is connected to the output end of the fourth comparator, the negative input end of the fourth comparator is connected to the reference voltage, and the positive input end of the fourth comparator is connected to the ground through the twelfth resistor.

11. The control device according to any one of claims 1 to 5, wherein the power-taking circuit includes:

a third switch;

the microphone terminal is connected to ground through the third switch.

12. The control device according to any one of claims 1 to 5, characterized by further comprising:

a second voltage detection control circuit;

the microphone end of the earphone is connected to the input end of the signal processing circuit of the earphone through the second voltage detection control circuit, the second voltage detection control circuit is used for generating and sending a fourth signal to the signal processing circuit, and the fourth signal is used for representing the voltage condition of the microphone end.

13. The control device according to claim 12, wherein the second voltage detection control circuit includes:

a thirteenth resistance and a fourteenth resistance;

the microphone end of the earphone is connected to one end of the fourteenth resistor through the thirteenth resistor, the microphone end of the earphone is connected to the signal processing circuit through the thirteenth resistor, and the other end of the fourteenth resistor is grounded.

14. The control device according to any one of claims 1 to 5, characterized by further comprising:

a fourth switch;

the energy storage circuit of the earphone is connected to the biological characteristic detection module of the earphone through a fourth switch, and the signal processing circuit of the earphone is used for controlling the fourth switch to be switched on or switched off.

15. The control device according to claim 14, characterized by further comprising:

the second low dropout regulator LDO;

the energy storage circuit is connected with one end of a second LDO, the other end of the second LDO is connected to the ground through a fifth capacitor, and the other end of the second LDO is further connected to the biological characteristic detection module through the fourth switch.

16. The control device according to claim 15, characterized by further comprising:

a sixth capacitor;

the other end of the second LDO is connected to the ground through a sixth capacitor.

17. The control device according to any one of claims 1 to 5, wherein the voltage protection circuit is a third LDO.

18. The control device according to any one of claims 1 to 5, wherein the voltage protection circuit includes:

a third MOS tube, a fifth comparator and a fifteenth resistor;

the microphone end is connected with the third MOS tube;

the negative input end of the fifth comparator is connected with the threshold voltage, the positive input end of the fifth comparator is connected with the microphone end, and the output end of the fifth comparator is connected to the gate of the third MOS transistor through the fifteenth resistor.

19. The control device of claim 18, wherein the voltage protection circuit further comprises:

a fourth MOS transistor and a sixteenth resistor;

the drain electrode of the fourth MOS tube is connected with the drain electrode of the third MOS tube;

the output end of the fifth comparator is connected to the gate of the third MOS transistor through the sixteenth resistor.

20. A wired headset, comprising:

the control device of any one of claims 1 to 19.

21. The wired headset of claim 20, wherein the control device is disposed within a line control board of the wired headset.