CN215222474U - Earphone set - Google Patents
Earphone set Download PDFInfo
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- CN215222474U CN215222474U CN202121727916.9U CN202121727916U CN215222474U CN 215222474 U CN215222474 U CN 215222474U CN 202121727916 U CN202121727916 U CN 202121727916U CN 215222474 U CN215222474 U CN 215222474U
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Abstract
The application discloses earphone belongs to the technical field of electron. The earphone includes: the device comprises an interface, a first frequency selection circuit, a second frequency selection circuit, a coder-decoder and a loudspeaker; the interface is connected with the loudspeaker through the first frequency selection circuit to form a first analog audio channel of the earphone; the interface is also connected with the loudspeaker through the second frequency selection circuit and the coder-decoder to form a first digital audio channel of the earphone; wherein the interface is operable to receive a first audio signal from an external device, the first audio signal being transmitted over the first analog audio path if the frequency of the first audio signal is in a first frequency range; the first audio signal is transmitted over the first digital audio path if the frequency of the first audio signal is in a second frequency range.
Description
Technical Field
The application belongs to the technical field of electronics, concretely relates to earphone.
Background
Along with the development of electronic technology, the mobile phone integration level is higher and higher, and the traditional 3.5mm earphone jack on the mobile phone is slowly cancelled, and the Type-C interface is replaced. The left and right channels of the Type-C interface share a USB differential signal path, so that a switch needs to be added on the mobile phone side. Referring to the mobile phone side circuit shown in fig. 1, the processor AP is connected to the USB circuit and the audio processing circuit, respectively, the USB circuit is used for processing USB signals, and the audio processing circuit mainly performs analog-digital audio signal conversion. When the mobile phone detects that the Type-C interface is inserted into the USB device, the switch is switched to a differential signal path of the USB, namely a pin DN _ L is connected with a USB _ DN port of the USB circuit through a DN port of the switch, and a pin DP _ R is connected with a USB _ DP port of the USB circuit through a DP port of the switch. When the mobile phone detects that the Type-C interface is inserted into the earphone, the switch is switched to a left channel and a right channel, namely the pin DN _ L is connected with the left channel port HP _ L of the audio processing circuit through the port L of the switch, and the pin DP _ R is connected with the right channel port HP _ R of the audio processing circuit through the port R of the switch.
Disclosure of Invention
An object of the embodiments of the present application is to provide a headset capable of compatibly supporting a digital audio mode and an analog audio mode.
In a first aspect, an embodiment of the present application provides an earphone.
The earphone comprises an interface, a first frequency selection circuit, a second frequency selection circuit, a coder-decoder and a loudspeaker;
the interface is connected with the loudspeaker through the first frequency selection circuit to form a first analog audio channel of the earphone;
the interface is also connected with the loudspeaker through the second frequency selection circuit and the coder-decoder to form a first digital audio channel of the earphone;
wherein the interface is operable to receive a first audio signal from an external device, the first audio signal being transmitted over the first analog audio path if the frequency of the first audio signal is in a first frequency range; the first audio signal is transmitted over the first digital audio path if the frequency of the first audio signal is in a second frequency range.
Optionally, the headset further comprises a microphone; the microphone is connected with the interface through the codec and the second frequency selection circuit to form a second digital audio path of the headset.
Optionally, the first frequency range is 20Hz to 20 KHz; the second frequency range is 12MHz or greater.
Optionally, the first frequency selective circuit comprises a low pass filter.
Optionally, the second frequency selective circuit comprises a high pass filter.
Optionally, the first frequency selective circuit includes a first magnetic bead.
Optionally, the impedance of the first magnetic bead is 2Kohm @100 MHz.
Optionally, the second frequency selective circuit comprises a first capacitor and a notch network; the first capacitor is connected between the interface and the codec, and the notch network is connected between one end of the first capacitor and ground.
Optionally, the trap network includes a second magnetic bead and a second capacitor connected in series, the second magnetic bead is connected to one end of the first capacitor, and the second capacitor is connected to ground.
Optionally, the impedance of the second magnetic bead is 2Kohm @100MHz, the capacitance value of the first capacitor is 470pF, and the capacitance value of the second capacitor is 1000 pF.
Optionally, the interface is a Type-C interface.
In the embodiment of the application, a first frequency selection circuit, a second frequency selection circuit and a codec are provided in the earphone, an analog audio signal path is realized by using the first frequency selection circuit, and a digital audio signal path is realized by using the second frequency selection circuit and the codec, so that the earphone can compatibly support a digital audio mode and an analog audio mode.
Drawings
FIG. 1 is a circuit diagram of a conventional Type-C interface on the handset side;
fig. 2 is a schematic diagram of a headset provided by an embodiment of the present application;
FIG. 3 is a schematic diagram of an analog audio mode of a headset provided by an embodiment of the present application;
fig. 4 is a schematic diagram of a digital audio mode of a headset provided by an embodiment of the present application;
fig. 5 is a circuit diagram of an earphone according to an embodiment of the present application;
fig. 6 is a circuit diagram of an earphone according to an embodiment of the present application;
fig. 7 is a circuit diagram of an earphone according to an embodiment of the present application;
fig. 8 is a schematic diagram of a headset provided by an embodiment of the present application;
fig. 9 is a frequency response graph of a headset according to an embodiment of the present application;
fig. 10 is a block diagram of a mobile phone provided in an embodiment of the present application;
fig. 11 is a schematic circuit diagram of a Type-C interface of a mobile phone according to an embodiment of the present application;
fig. 12 is a flowchart of a mode switching process of a terminal according to an embodiment of the present application;
fig. 13 is a flowchart of a mode switching process of a terminal according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present disclosure.
The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.
Referring to fig. 2, embodiments of the present application provide a headset with analog/digital channel selection. Referring to fig. 3, the headset may operate in an analog audio mode (hereinafter referred to as "analog headset mode"). Referring to fig. 4, the headset may operate in a digital audio mode (hereinafter referred to as "digital headset mode"). The interface of the headset may be, for example, a Type-C interface.
Referring to fig. 2, the circuit structure of the handset side is similar to that of fig. 1, and the circuit of the headset side provides an analog channel and a digital channel, wherein the analog channel is connected between the interface of the headset and the speaker of the headset, the digital channel is connected between the interface of the headset and the codec of the headset, and the codec is connected to the speaker of the headset. The speakers may include a left channel speaker and a right channel speaker.
When the headset is in the analog headset mode, the audio signal is an analog audio signal and the signal flow is as shown in fig. 3. Specifically, on the handset side, the audio signal goes through conventional audio processing circuitry. That is, the direction of the audio signal flow is from the audio processing circuit of the handset, the switch of the handset, the Type-C interface of the headset, the analog channel of the headset, to the speaker of the headset.
When the headset is in the digital headset mode, the audio signal is a digital audio signal and the signal flow is as shown in fig. 4. Specifically, on the handset side, the audio signal goes through the USB circuit. That is, the direction of the audio signal flow is from the USB circuit of the handset, the switch of the handset, the Type-C interface of the headset, the digital channel of the headset, the codec of the headset, to the speaker of the headset.
In the embodiment of the disclosure, after the earphone is inserted into the terminal device, the terminal device may control the earphone to be in the analog earphone mode or the digital earphone mode through the earphone interface, and the terminal device may control whether the codec of the earphone enters the working state.
In the embodiment of the disclosure, the mobile phone may also be replaced with other terminal devices having a Type-C interface, and the terminal device may be, for example, a tablet computer, a wearable device, or the like.
In the disclosed embodiment, the analog channels shown in fig. 2-4 may be implemented with a first frequency selective circuit, and the digital channels may be implemented with a second frequency selective circuit.
Referring to the audio processing circuit diagram shown in fig. 5, the earphone provided by the embodiment of the present application includes: the device comprises an interface, a first frequency selection circuit, a second frequency selection circuit, a coder-decoder and a loudspeaker. The interface is connected with the loudspeaker through the first frequency selection circuit to form a first analog audio channel of the earphone. The interface is also connected with the loudspeaker through a second frequency selection circuit and a coder-decoder to form a first digital audio path of the earphone.
The interface may receive a first audio signal from the external device, the first audio signal being transmitted over the first analog audio path if a frequency of the first audio signal is in a first frequency range; the first audio signal is transmitted over the first digital audio path with a frequency of the first audio signal in a second frequency range.
That is to say, after the earphone is inserted into the external device, when the first audio signal output by the external device is an analog audio signal, the first audio signal sequentially passes through the interface of the earphone and the first frequency selection circuit to reach the speaker for playing. When the first audio signal output by the external device is a digital audio signal, the first audio signal sequentially passes through the interface of the earphone, the second frequency selection circuit and the codec to reach the loudspeaker for playing.
The frequency range of the analog audio signal is typically between 20Hz-20 KHz. The digital headset operates in a high rate mode, such as a 12Mbps rate mode of USB 2.0. That is, the digital audio signal transmitted by the headphone is higher in the frequency domain than the analog audio signal, and the digital audio signal used by the digital headphone is a high-frequency signal. The earphone of the embodiment of the application adopts the first frequency selection circuit and the second frequency selection circuit to divide the analog channel and the digital channel.
In the disclosed embodiment, the first frequency range is 20Hz to 20KHz, which may include 20Hz and 20 KHz. The second frequency range is 12MHz or greater.
In the embodiments of the present disclosure, the speakers are, for example, a left ear speaker corresponding to a left channel and a right ear speaker corresponding to a right channel. In the embodiment of the present disclosure, the interface of the earphone may be a Type-C interface, or other interfaces compatible with USB signals and analog audio signals.
Referring to fig. 6, in the embodiment of the present disclosure, the first frequency selection circuit may be implemented by using a low pass filter, and the passed frequency ranges from 20Hz to 20KHz, which may include 20Hz and 20 KHz. The second frequency selection circuit may be implemented using a high pass filter, and the range of frequencies passed is 12MHz or greater.
In one example, the circuit configuration of the headset is shown in fig. 7. The first frequency-selecting circuit comprises a low-pass filter formed by the first magnetic bead FB 1. The second frequency-selecting circuit comprises a high-pass filter formed by a first capacitor C1 and a notch network. A first capacitor C1 is connected between the interface and the codec, and a notch network is connected between one end of the first capacitor and ground. In one example, the notch network is connected between a first terminal of a first capacitor C1 and ground, the first terminal of the first capacitor C1 being the terminal connected to the codec. In one example, the notch network is connected between the second terminal of the first capacitor C1 and ground, and the second terminal of the first capacitor C1 is the terminal interfaced therewith. The trap network comprises a second magnetic bead FB2 and a second capacitor C2 which are connected in series, wherein the second magnetic bead FB2 is connected with one end of a first capacitor C1, and the second capacitor C2 is connected with the ground.
Referring to fig. 7, a differential signal pin DN _ L of the earphone Type-C interface corresponds to a left channel and is respectively connected to a first frequency selection circuit and a second frequency selection circuit, the first frequency selection circuit is connected to a speaker of the left channel, and the second frequency selection circuit is connected to the speaker of the left channel through a codec. A differential signal pin DN _ R of the earphone Type-C interface corresponds to a right sound channel and is respectively connected with a first frequency selection circuit and a second frequency selection circuit, the first frequency selection circuit is connected with a loudspeaker of the right sound channel, and the second frequency selection circuit is connected with the loudspeaker of the right sound channel through a coder-decoder.
Referring to fig. 7, in the digital headphone mode, a digital audio signal at the handset side enters the second frequency selection circuit through pins DN _ L and DN _ R of the headphone Type-C interface, and is converted into an analog audio signal by the codec and then transmitted to the speakers of the left and right channels. When the earphone mode is simulated, audio signals of left and right sound channels simulated at the mobile phone side enter the first frequency selection circuit through the base pin DN _ L and the base pin DN _ R of the earphone Type-C interface, so that the simulated audio signals are transmitted to the loudspeakers of the left and right sound channels of the earphone.
In one example, in the headset, the microphone is connected to the interface through the codec and the second frequency selection circuit to form a second digital audio path of the headset. A microphone on the headset captures a second audio signal from the outside that can be transmitted to the external device via the second digital audio path. Specifically, a second audio signal output by the microphone is an analog audio signal, the second audio signal is converted into a digital audio signal after being processed by the codec, and then the digital audio signal is transmitted to the external device through the second frequency selection circuit and the earphone Type-C interface.
Referring to fig. 7, the microphone of the earphone is respectively connected with the microphone pin MIC and the codec of the earphone Type-C interface. The microphone pin MIC of the earphone Type-C interface can be realized by adopting the SBU pin of the Type-C interface. Referring to fig. 7 and 8, in the digital headset mode, the sub-switch S1 in the switch circuit on the handset side is turned off, and the analog audio signal output by the headset microphone is converted into a digital audio signal by the codec, and then transmitted to the USB circuit on the handset side via the second frequency selection circuit and the pin DN _ L/pin DN _ R of the headset Type-C interface. When the earphone mode is simulated, a sub-switch S1 in the switch circuit of the mobile phone side is closed and conducted, and the analog audio signal output by the earphone microphone is directly output to a microphone pin MIC of an earphone Type-C interface and is transmitted to the audio processing circuit of the mobile phone side in the form of an analog signal.
Referring to the frequency response curve shown in fig. 9, the horizontal axis represents the frequency of the audio signal in MHz, and the vertical axis represents the response in dB. The preferred frequency response curve of the first frequency-selective circuit is Q1, and the preferred frequency response curve of the second frequency-selective circuit is Q2. The first frequency selection circuit can satisfy a frequency response curve Q1 when the device is in a type selection mode, and the second frequency selection circuit can satisfy a frequency response curve Q2 when the device is in a type selection mode. In one example, the device types of the first frequency selecting circuit and the second frequency selecting network can be selected, and the device values can be divided into analog audio channels and digital audio channels.
In one example, the impedance of the first magnetic bead FB1 is 2Kohm @100 MHz. The impedance of the second magnetic bead FB2 is 2Kohm @100MHz, the capacitance value of the first capacitor C1 is 470pF, and the capacitance value of the second capacitor C2 is 1000 pF.
The earphone of the embodiment of the disclosure introduces a frequency selection circuit into the earphone so that the earphone is provided with two analog/digital transmission channels. The frequency selection circuit can be realized purely through passive devices, and the realization cost is low.
The conventional antenna layout of a mobile phone is shown in fig. 10, where an upper antenna a1 is located at the top of the mobile phone, a lower antenna a4 is located at the bottom of the mobile phone, a circuit board is located at the upper part of the mobile phone, a battery is located at the lower part of the mobile phone, a radio frequency transmission line a2 between the lower antenna a4 and the circuit board is arranged along one side of the mobile phone, and a Type-C interface A3 of the mobile phone is located at the bottom of the mobile phone. The inventor has found through research and analysis that since a digital signal generally has a wider wideband noise in the frequency domain, when the Type-C interface is transmitting a digital audio signal, the wideband noise may seriously affect the communication quality of the lower antenna a4 in a weak signal coverage area since the Type-C interface is near the lower antenna. When the earphone is in the digital earphone mode, compared with the traditional analog Type-C earphone, normal cellular network communication can be interfered, and the earphone can listen to music, watch videos and make a call, which is a scene with higher use frequency of a user, so that the digital earphone mode can improve the tone quality and actually reduce the cellular communication quality of the mobile phone. In addition, since the handset usually uses the earphone cable (left/right channel/ground) as FM (frequency modulation broadcast signal) antenna, the FM operating frequency is 87-108MHz, which is lower than the frequency of cellular communication, when the earphone is in digital earphone mode, the wideband noise generated in the FM frequency band is larger, and the interference to FM is fatal.
In order to better use the earphone compatible with the analog mode and the digital mode provided by the application, the disclosed embodiment provides a circuit of a terminal device. The following description will be given taking a mobile phone circuit shown in fig. 11 as an example.
In the embodiment of the disclosure, after the earphone is inserted into the mobile phone, the mobile phone can control whether the earphone is in an analog earphone mode or a digital earphone mode through the interface of the earphone, and the mobile phone can control whether the codec of the earphone enters a working state.
As shown in fig. 11, the processor AP control logic PMIC sends out a control signal to control the switch to switch according to the communication quality of the cell and FM. The port DET1 and the port DET2 of the logic PMIC are connected to the Type-C interface and switch of the handset, the port DET1 corresponds to the left channel and the port DET2 corresponds to the right channel. When the port DET1 and the port DET2 are at a low level, the mobile phone controls the earphone to enter an analog earphone mode, the mobile phone adaptive earphone works in the analog mode, a path from a pin DN _ L of a Type-C interface of the mobile phone to a left channel port HP _ L is conducted, a path from a pin DP _ R of the Type-C interface of the mobile phone to a right channel port HP _ R is conducted, and the sub-switch S1 is closed. When the port DET1 and the port DET2 are at high level, the mobile phone controls the earphone to enter a digital earphone mode, the mobile phone adaptive earphone works in the digital mode, a channel from a pin DN _ L of a Type-C interface of the mobile phone to a port USB _ DN is switched on, a channel from a pin DP _ R of the Type-C interface of the mobile phone to a port USB _ DP is switched on, and the sub-switch S1 is switched off.
In the analog headset mode, the codec inside the headset is in the standby mode, the handset outputs an analog audio signal, and the signal flow from the handset to the headset is as shown in fig. 3. The analog headset mode does not interfere with cellular and FM systems. In the digital headset mode, the codec inside the headset is in a normal operating state, and the output of the handset is a digital audio signal, and the signal flow from the handset to the headset is as shown in fig. 4.
In one example, when the handset detects that the user is plugged into the headset, the headset defaults to a digital headset mode of operation. The mobile phone detects the signal intensity of the current cellular network in real time or whether the mobile phone has FM on.
Referring to fig. 12 and 13, when the signal strength of the cellular network of the handset is lower than a set first threshold (the first threshold is-85 dBm, for example) or the handset has an FM on action, the handset control switch performs a switching action, and the headset switches to an analog headset operating mode to reduce the influence on the cellular network and the FM. And when the signal intensity of the cellular network of the mobile phone is higher than or equal to the set first threshold value, or after the user quits the FM function, the earphone is recovered to the digital earphone working mode.
In another embodiment, the headset switches to the analog headset mode when the signal strength of the FM is below a set second threshold after the user turns on the FM. And when the signal strength of the FM is higher than or equal to the set second threshold value, the earphone returns to the digital earphone working mode.
Because the existing terminal has designed a switch, the Type-C interface of the terminal can be switched between USB transmission and analog audio transmission, and through the scheme of the embodiment of the application, a digital channel frequency selection network and an analog channel frequency selection network are added in the earphone and matched with the terminal for use, so that a user can switch between a digital earphone mode and an analog earphone. When the earphone works in a digital earphone mode and causes large interference to a cellular network or FM, the earphone is switched to an analog earphone mode to meet basic functional requirements of a user, and when the signal coverage of the cellular network is good or the user does not use the FM function, the earphone works in the digital earphone mode to meet the requirements of the user on high tone quality.
While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. An earphone is characterized by comprising an interface, a first frequency selection circuit, a second frequency selection circuit, a coder-decoder and a loudspeaker;
the interface is connected with the loudspeaker through the first frequency selection circuit to form a first analog audio channel of the earphone;
the interface is also connected with the loudspeaker through the second frequency selection circuit and the coder-decoder to form a first digital audio channel of the earphone;
wherein the interface is operable to receive a first audio signal from an external device, the first audio signal being transmitted over the first analog audio path if the frequency of the first audio signal is in a first frequency range; the first audio signal is transmitted over the first digital audio path if the frequency of the first audio signal is in a second frequency range.
2. The headset of claim 1, further comprising a microphone;
the microphone is connected with the interface through the codec and the second frequency selection circuit to form a second digital audio path of the headset.
3. The headset of claim 1, wherein the first frequency range is 20Hz to 20 KHz; the second frequency range is 12MHz or greater.
4. The headset of claim 1, wherein the first frequency selective circuit comprises a low pass filter.
5. The headset of claim 1, wherein the second frequency selective circuit comprises a high pass filter.
6. The headset of claim 1, wherein the first frequency selective circuit comprises a first magnetic bead.
7. The headset of claim 1, wherein the second frequency selective circuit comprises a first capacitor and a notch network;
the first capacitor is connected between the interface and the codec, and the notch network is connected between one end of the first capacitor and ground.
8. The earphone of claim 7, wherein the notch network comprises a second bead and a second capacitor connected in series, the second bead being connected to one end of the first capacitor, the second capacitor being connected to ground.
9. The earpiece of claim 8, wherein the second bead has an impedance of 2Kohm @100MHz, the first capacitor has a capacitance of 470pF, and the second capacitor has a capacitance of 1000 pF.
10. The headset of claim 1, wherein the interface is a Type-C interface.
Priority Applications (1)
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CN202121727916.9U CN215222474U (en) | 2021-07-27 | 2021-07-27 | Earphone set |
Applications Claiming Priority (1)
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CN202121727916.9U CN215222474U (en) | 2021-07-27 | 2021-07-27 | Earphone set |
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CN215222474U true CN215222474U (en) | 2021-12-17 |
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CN202121727916.9U Active CN215222474U (en) | 2021-07-27 | 2021-07-27 | Earphone set |
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