CN110783777B

CN110783777B - Anti-interference method, device and system

Info

Publication number: CN110783777B
Application number: CN201810764616.4A
Authority: CN
Inventors: 刘波
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2018-07-12
Filing date: 2018-07-12
Publication date: 2022-02-18
Anticipated expiration: 2038-07-12
Also published as: CN110783777A

Abstract

The invention discloses an anti-interference device, comprising: the earphone comprises a Type-C interface, a first switch for transmitting a microphone signal, a second switch for transmitting an earphone signal and a first processor; a microphone signal pin of the Type-C interface is connected with the first processor through the first switch; the earphone receiver signal pin of the Type-C interface is connected with the first processor through the second switch, the ground output end of the first switch is connected with the ground end of the second switch through a special ground, and the special ground is different from a common ground. The embodiment of the invention also provides an anti-interference method and an anti-interference system.

Description

Anti-interference method, device and system

Technical Field

The embodiment of the invention relates to the field of communication, in particular to but not limited to an anti-interference method, device and system.

Background

Along with the popularization of the USB Type-C interface, more and more terminal manufacturers begin to try to switch the USB interface to the Type-C interface, still define the interface of simulation earphone specially in the Type-C agreement, use the layout space that the compatible earphone design of Type-C interface just can save 3.5mm earphone interface, can let the cell-phone seem more succinct, and is dustproof, and waterproof ability is also stronger.

If the digital earphone of the USB Type-C interface is used, the influence on the earphone index is large, a large amount of delay can be caused in the process that the digital earphone is converted through a USB signal, the conversation performance of the earphone is influenced to a certain extent, a digital-to-analog conversion module needs to be arranged in the digital earphone, and the function of realizing the conversation while charging through a USB one-to-two switching line cannot be realized.

If the analog earphone of Type-C interface is used, a lot of defects of the digital earphone can be made up, firstly, a USB signal conversion link is saved, the same call delay with the traditional 3.5mm earphone can be achieved, in addition, the Type-C analog earphone supports positive and negative insertion, and the problem of compatibility of American and European standard earphones can be completely solved in the design of hardware by the aid of the method. Simultaneously, the audio interface of USBType-C simulation earphone and the interface that charges are not shared, use one minute two patch cords can also accomplish multimedia playback or conversation function when charging.

But the circuit interference killing feature of current Type-C simulation earphone is not enough, and the current sound appears more easily during the conversation, leads to speech quality to receive the influence.

Disclosure of Invention

In view of the above, embodiments of the present invention are intended to provide an anti-interference method, apparatus, and system, which can reduce noise of an earphone during a passing process.

The technical scheme of the embodiment of the invention is realized as follows:

the embodiment of the invention provides an anti-interference device, which comprises: the earphone comprises a Type-C interface, a first switch for transmitting a microphone signal, a second switch for transmitting an earphone signal and a first processor;

a microphone signal pin of the Type-C interface is connected with the first processor through the first switch;

the earphone receiver signal pin of the Type-C interface is connected with the first processor through the second switch, the ground output end of the first switch is connected with the ground end of the second switch through a special ground, and the special ground is different from a common ground.

The embodiment of the invention also provides an anti-interference method which is applied to the anti-interference device provided by the embodiment of the invention, and the method comprises the following steps:

the first processor receives a microphone signal input by a microphone signal pin of the Type-C interface through a first switch, and outputs a headphone signal to a headphone signal pin of the Type-C interface through a second switch;

and taking the ground signal of the microphone signal as the ground signal of the earphone signal through the connection of the ground output end of the first switch and the ground end of the second switch.

An embodiment of the present invention further provides an anti-interference system, where the system includes: the anti-interference device comprises an earphone, a converter and a terminal, wherein the terminal comprises the anti-interference device provided by the embodiment of the invention.

The embodiment of the invention provides an anti-interference method, an anti-interference device and an anti-interference system, wherein the anti-interference device comprises: the earphone comprises a Type-C interface, a first switch for transmitting a microphone signal, a second switch for transmitting an earphone signal, a third switch for transmitting a USB signal, a first processor and a second processor; a microphone signal pin of the Type-C interface is connected with the first processor through the first switch; the earphone receiver pin of the Type-C interface is connected with the first processor through the second switch, the ground output end of the first switch is connected with the ground end of the second switch through a special ground, and the special ground is different from a common ground; therefore, the ground connected with the first switch for transmitting the microphone signal is connected with the ground connected with the second switch for transmitting the earphone signals, and is separated from the public ground, the path of the signal forms a backflow ground path, and the noise generated to the public ground during the charging current is isolated from the ground of the signal, so that the current transmission does not influence the earphone signals, the anti-interference capability of the earphone signals is improved, and the quality of the earphone signals played by the earphone is further improved.

Drawings

Fig. 1-1 is a schematic structural diagram of an anti-interference apparatus according to a first embodiment of the present invention;

fig. 1-2 are schematic structural diagrams of an anti-interference apparatus according to a first embodiment of the present invention;

fig. 2 is a schematic flowchart of an anti-interference method according to a second embodiment of the present invention;

fig. 3 is a schematic structural diagram of an anti-interference system according to a third embodiment of the present invention;

fig. 4 is a circuit diagram of a converter according to a fourth embodiment of the present invention;

fig. 5 is a schematic circuit diagram of an anti-interference apparatus according to a fifth embodiment of the present invention;

fig. 6 is a schematic flowchart of a method for detecting insertion of an earphone according to a fifth embodiment of the present invention;

fig. 7 is a schematic circuit diagram of an anti-interference apparatus according to a sixth embodiment of the present invention;

fig. 8 is a schematic flowchart of an anti-interference method according to a sixth embodiment of the present invention.

Detailed Description

In an embodiment of the present invention, the apparatus comprises: the earphone comprises a Type-C interface, a first switch for transmitting a microphone signal, a second switch for transmitting an earphone signal and a first processor; a microphone signal pin of the Type-C interface is connected with the first processor through the first switch; the earphone receiver signal pin of the Type-C interface is connected with the first processor through the second switch, the ground output end of the first switch is connected with the ground end of the second switch through a special ground, and the special ground is different from a common ground.

The following describes the embodiments in further detail with reference to the accompanying drawings.

Example one

An embodiment of the present invention provides an anti-interference apparatus, as shown in fig. 1-1, the anti-interference apparatus includes: a Type-C interface 101, a first switch 102 for transmitting a microphone signal, a second switch 103 for transmitting a headphone signal, and a first processor 105; a microphone signal pin of the Type-C interface 101 is connected with the first processor 105 through the first switch 102; the earphone handset signal pin of the Type-C interface 101 is connected with the first processor 105 through the second switch 103, the ground output end of the first switch 102 is connected with the ground end of the second switch 102 through the special ground 104, and the special ground 104 is different from the common ground.

In one embodiment, as shown in fig. 1-2, the apparatus further comprises: a second processor 106 and a third switch 107 for transmitting a USB signal;

a headphone signal pin of the Type-C interface 101 is connected with the second processor 106 through the third switch 107; the ground of the third switch 106 is connected to the common ground 108.

Here, the private ground 104 is different from the common ground 108, and the private ground 104 is absolutely connected to the common ground 108 via a connection carrier such as a magnetic bead capable of isolating signals, so as to isolate interference of the common ground 108; common ground 108 serves as a common ground for the terminals and may be ground GND on the PCB board.

One or more of the first switch, the second switch, and the third switch may be a tri-state switch including three switch states of high-impedance off, sequential on, and cross-over. Wherein, the high resistance disconnection is the state when the earphone does not insert the Type-C interface, and the order switches on the state when inserting the Type-C interface for the earphone, and the cross-over switches on the state when inserting the Type-C interface for the earphone is anti-.

The first Processor may be a Codec for performing audio processing such as Codec, analog-to-digital conversion, and signal amplification on the audio signal, and the second Processor may be an Application Processor (AP).

As shown in fig. 1-2, a level detection pin of the Type-C interface is connected to the second processor, and the level detection pin is used to trigger an earphone insertion signal.

When the level of the level detection pin of the Type-C interface changes, the current earphone insertion is detected, the earphone insertion signal is enabled, and the earphone insertion signal is sent to the second processor to inform the second processor of the current earphone insertion.

It should be noted that, when an adapter such as a patch cord with a Type-C interface is separately connected to a terminal, the level of the level detection pin of the terminal does not change, and it is considered that an earphone is not currently plugged in. When only the adaptor of the inserted earphone is accessed to the terminal, the level of the level detection pin of the terminal is changed based on the level change of the level detection pin (first detection pin) of the inserted adaptor of the earphone, so that the insertion of the earphone is detected.

When the earphone is detected to be inserted into the Type-C interface, the first switch is set to be in a sequential conducting state, and the microphone impedance of the inserted earphone is detected through the microphone signal pin so as to detect whether the inserted earphone comprises a microphone or not. If the microphone impedance of the inserted earphone is 0 ohm, determining that the current earphone does not comprise a microphone; if the microphone impedance of the inserted earphone is the set impedance, determining that the current earphone comprises a microphone; if the microphone impedance of the inserted earphone does not meet the set impedance, the first switch is set to be in a cross conduction state, and the microphone impedance of the inserted earphone is continuously detected. And if the microphone impedance of the inserted earphone meets the set impedance, determining that the current earphone comprises a microphone, otherwise, determining that the earphone state is abnormal.

After the terminal is connected with the Type-C analog earphone, the microphone signal pin in the Type-C interface transmits the microphone signal received from the earphone, namely, the audio signal collected by the microphone of the earphone, the earphone receiver signal pin in the Type-C interface transmits the audio signal at the terminal to the left and right sound channels of the earphone, and the third switch connects the earphone receiver signal pin of the Type-C interface with the USB data anode D +/data cathode D-of the second processor 106 for transmitting the digital signal.

It should be noted that, when the earphone inserted into the terminal is an analog earphone with a Type-C interface, the first switch and the second switch are in an on state for transmitting a microphone signal and an earphone signal, and the third switch is in an off state.

The first switch connected with the microphone signal pin transmits a microphone signal, the second switch connected with the earphone signal pin transmits an earphone signal, and the third switch connected with the earphone signal pin transmits a USB signal, wherein the first switch and the second switch are grounded in the same way and are special grounds, and the third switch is grounded independently from the first switch and the second switch and is a common ground, so that noise generated by charging current to the common ground is isolated from the grounds of the microphone signal and the earphone signal, and the interference to the microphone signal and the earphone signal is avoided.

The microphone signal pins of the Type-C interface 101 comprise a first microphone signal pin and a second microphone signal pin; the first microphone signal pin is used for transmitting a microphone input signal, and the second microphone signal pin is used for transmitting a microphone ground signal; the first microphone signal pin is connected with the first processor 105 through the first switch 102; the second microphone signal pin is connected with the ground output end of the first switch 102; the ground output of the first switch 102 is connected to the first processor 102.

Here, the microphone input signal transmitted by the earphone includes an interference signal received by a microphone of the earphone, and the microphone ground signal is connected with the grounds of the first switch and the second switch to be used as the ground signal of the first switch and the second switch, so that the interference signal in the microphone signal is used as the ground signal of the earphone receiver signal output.

In an embodiment, the first processor 101 comprises a differential amplifier; the first microphone signal pin is connected with the first input end of the differential amplifier through the first switch; the ground output end of the first switch is connected with the second input end of the differential amplifier.

Here, the mike ground signal includes an interference signal received by a mike of the earphone, the mike input signal is input to the first input terminal of the differential amplifier through the connection of the first mike signal pin and the first input terminal of the differential amplifier, and the mike ground signal is input to the second input terminal of the differential amplifier through the connection of the ground output terminal of the first switch and the second input terminal of the differential amplifier. The differential amplifier differentially amplifies the input microphone input signal and the microphone ground signal, cancels the interference signal in the microphone input signal, and filters the interference signal to be small enough by the output signal.

In one embodiment, the headphone signal pin comprises a first channel pin and a second channel pin; the first processor comprises a first headphone amplifier and a second headphone amplifier; the first channel pin is connected with the input end of the first earphone amplifier through the second switch; and the second channel pin is connected with the input end of the second earphone amplifier through the second switch.

The headphone signal includes a first channel signal and a second channel signal of the headphone, and the first channel signal may be a left channel signal, and correspondingly, the second channel signal is a right channel signal. Here, the first channel signal pin is used for transmitting a first channel signal of the headphone, and the second channel signal pin is used for transmitting a second channel signal of the headphone, and the first processor sends the first channel signal and the second channel signal to a first headphone amplifier and a second headphone amplifier of the first processor, respectively, so as to amplify the first channel signal and the second channel signal, respectively.

In one embodiment, the ground output of the first switch is connected to the ground reference of the first headphone amplifier and the ground reference of the second headphone amplifier, respectively.

At this time, the ground reference ends of the first headphone amplifier and the second headphone amplifier are both mike ground signals, at this time, the first headphone amplifier and the second headphone amplifier take the mike ground signals as reference, the first channel signal output by the first headphone amplifier to the first channel pin will form an inverse signal equal to that on the mike ground signals, and the second channel signal output by the second headphone amplifier to the second channel pin will also form an inverse signal equal to that on the mike ground signals, so as to cancel the interference in the headphone cable.

It should be noted that in the embodiment of the present invention, the analog earphone of the Type-C interface may be inserted into the terminal directly, or may be inserted into analog earphones of other interface standards such as 3.5mm through a patch cord of the Type-C interface.

In the embodiment of the invention, the Type-C interface, the first switch, the second switch, the third switch, the first processor and the second processor are arranged in the first switch; a microphone signal pin of the Type-C interface is connected with the first processor through the first switch; the earphone receiver signal pin of the Type-C interface is connected with the first processor through the second switch, and the ground output end of the first switch is connected with the ground end of the second switch; the earphone receiver signal pin of the Type-C interface is connected with the second processor through the third switch; and the ground end of the third switch is grounded. When inserting Type-simulation earphone through the Type-C interface, connect the ground connection of earphone signal and the ground connection of wheat examination signal to keep apart with publicly, make the electric current signal can not exert an influence to earphone signal, improve the interference killing feature at terminal, reduce the noise through the in-process earphone.

The anti-jamming device provided by the embodiment of the invention can support the identification of all the current analog earphones (including a four-section American standard earphone, a four-section European standard earphone and a three-section earphone) during the positive and negative insertion of the USB through the matching of a circuit and software, ensures that no current sound occurs when a call is made under the charging condition by using a one-to-two switching line through a special anti-jamming device, and ensures that no noise occurs during the playing when the earphone is used for calling through a special anti-jamming design.

Example two

In an embodiment of the present invention, an anti-interference method applied to the anti-interference apparatus shown in fig. 1 provided in the first embodiment is provided, and as shown in fig. 2, the method includes:

s201, a first processor receives a microphone signal input by a microphone signal pin of the Type-C interface through a first switch, and outputs a headphone signal to a headphone signal pin of the Type-C interface through a second switch;

here, the method further includes: when the level detection pin of the Type-C interface detects the level change, triggering an earphone insertion signal; sending the headset insertion signal to a second processor. The second processor is informed by the headset insert signal that the headset is currently inserted.

After the terminal is connected with the Type-C analog earphone, a microphone signal pin in the Type-C interface transmits a microphone signal received from the earphone, namely, an audio signal collected by a microphone of the earphone, and an earphone signal pin in the Type-C interface transmits the audio signal (namely, an earphone signal) of the terminal to the left and right sound channels of the earphone.

And S202, taking the ground signal of the microphone signal as the ground signal of the earphone signal through the connection of the ground output end of the first switch and the ground end of the second switch.

At this time, the first switch and the second switch are simultaneously connected to the dedicated ground, and the ground signals of the first switch and the second switch are the same ground signal, that is, an absolute ground signal of the dedicated ground.

Here, the method further includes: and taking a microphone ground signal in the microphone signals as a ground signal of the earphone signals. At the moment, a second microphone signal pin for transmitting a microphone ground signal is connected with a ground output end of the first switch through the first switch; the ground output end of the first switch is connected with the ground end of the second switch, so that the mike ground signal is used as the ground signal of the earphone signals, the interference signal in the mike signals is used as the ground signal of the output earphone signals, and the earphone signals can be effectively offset and processed based on the known interference signal at the earphone side, so that the quality of the earphone signals is improved.

The first processor may comprise a differential amplifier, and in this case, a mike input signal in the mike signal and the mike ground signal are respectively used as input signals of the first differential amplifier in the first processor; and carrying out differential amplification processing on the microphone input signal and the microphone ground signal through the differential amplifier. The mike input signal and the mike ground signal are differentially processed by a differential amplifier, and an interference signal included in the mike ground signal is subtracted from the mike input signal.

The headphone signals comprise a first channel signal and a second channel signal; the first processor comprises a first headphone amplifier and a second headphone amplifier, the method further comprising: amplifying the first sound channel signal through the first headphone amplifier; and amplifying the second channel signal by the second earphone amplifier.

The amplifying the first channel signal by the first headphone amplifier, and the amplifying the second channel signal by the second headphone amplifier includes: taking the mike ground signal as a ground reference signal of the first headphone amplifier to amplify the first channel signal; and taking the mike ground signal as a ground reference signal of the second earphone amplifier to amplify the second channel signal.

Here, the ground reference terminals of the first headphone amplifier and the second headphone amplifier are both mike ground signals, and at this time, the first headphone amplifier and the second headphone amplifier use the mike ground signals as reference, the first channel signal output by the first headphone amplifier to the first channel pin will form an inverse signal equal to that on the mike ground signals, and the second channel signal output by the second headphone amplifier to the second channel pin will also form an inverse signal equal to that on the mike ground signals, so as to cancel the interference in the headphone cable.

In practical application, when the terminal is plugged into the Type-C analog earphone through the one-to-two patch cord, the third switch for transmitting the USB signal is in an off state.

Here, the microphone input signal transmitted by the earphone includes an interference signal received by a microphone of the earphone, and the ground signal of the microphone is used as the ground signal of the first switch and the second switch, so that the interference signal is used as the ground signal of the earphone receiver signal to be output.

EXAMPLE III

Based on the anti-interference device provided in the first embodiment, an embodiment of the present invention further provides an anti-interference system, as shown in fig. 3, the system includes: a headset 301, a converter 302 and a terminal 303, the terminal 303 comprising the interference rejection means as provided in the first embodiment.

The plug of the earphone 301 is inserted into the first interface of the converter 302 and the second interface of the converter 302 is inserted into the Type-C interface of the terminal 303. Wherein the first interface of the transducer is matched with the jack of the headset 301, such as: the plug of the earphone 301 is a 3.5mm plug, and the first interface is an earphone socket corresponding to the 3.5mm plug. The second interface of converter is Type-C interface, for example: the second interface of converter is female head of Type-C interface, and the Type-C interface of terminal 303 is public head of Type-C interface.

In one embodiment, the earphone socket of the converter 302 is provided with a first detection pin and a second detection pin; the first detection pin is connected with a level detection pin of a Type-C interface of the converter; the second detection pin is grounded. The level detection pin may be a Configuration Channel (CC) pin and a VCONN pin corresponding to the CC pin. Here, the Type-C based interface supports forward and reverse insertion, and thus, the CC pin and the VCONN pin are forward and reverse pins of the same function. The VCONN pin can also be referred to as a PWR _ Vcoon pin and is mainly used for assisting in detecting the Type of the Type-C device.

In the related art, a common earphone patch cord is designed such that a left channel pin of an earphone and an insertion detection pin are normally open (Normal open no), when the earphone is not inserted, the left channel pin of the earphone and the detection pin are in a disconnected state, when the earphone is inserted, the left channel pin of the earphone and the detection pin are in a short circuit, and the detection pin is detected to be at a low level to judge that the earphone is inserted. However, in this scheme, the left channel signal is easily affected by noise on the detection pin, which causes a decrease in audio quality.

In the embodiment of the invention, after the earphone is inserted, the two detection pins, namely the first detection pin and the second detection pin, are conducted, that is, the CC pin is grounded to form a low level, and then the earphone is judged to be inserted. The scheme detects that the pin is not communicated with the left channel signal pin any more, and does not cause any influence on the signal quality of the earphone receiver.

Example four

In the embodiment of the present invention, the plug of the inserted earphone is a 3.5mm audio plug, for example, which is further described as an adapter in the anti-interference system.

As shown in fig. 4, including 3.5mm audio plug and USB Type-C adapter (adapter), 3.5mm audio plug inserts in the earphone seat of adapter. The pins of the 3.5mm audio plug include a ground AGND/MIC pin, a RIGHT channel RIGHT pin, and a LEFT channel LEFT pin. The earphone seat of adapter has two detection pins of NO, and a detection pin ground connection, another detection pin receive the CC pin of Type-C interface. When the earphone is inserted, the two detection pins are conducted, namely the CC pin is grounded, and low level particles are formed to judge that the earphone is inserted. The scheme detects that the pin is not communicated with the left channel signal pin any more, and does not cause any influence on the signal quality of the earphone receiver.

EXAMPLE five

The circuit structure of the interference rejection apparatus in the embodiment of the present invention is further described.

In the related art, the positive data Dp/negative data Dn of the Type-C USB is connected to two switches, the signal is connected to the left and right channels of the earphone through one switch, and is connected to the D +/D-of the USB through the other switch, and the Side Band Use (SBU) 1/SBU2 is connected to the codec (corresponding to the first processor in the first embodiment) through the switch, and each switch is connected to ground. In the design, each path of signal of the earphone is respectively connected to different grounds and is finally connected to a common ground, so that when the USB is charged, each path of signal of the earphone generates noise due to interference of charging current to noise near the common ground.

The anti-interference device provided by the embodiment of the invention can perform earphone ground isolation and negative feedback elimination, as shown in fig. 5, the earphone reference ground and the headset reference ground MIC _ GND are pulled to codec (as shown by a dotted line in the figure) for negative terminal elimination, and meanwhile, the grounding of an earphone circuit is digitally and completely separated from USB, so that an independent return ground path is formed, and the anti-interference effect is achieved.

The SBU1/SBU2 signal is connected to the microphone input of codec and the ground signal through switch a (first switch), which is a typical three-state switch that can satisfy three states of high-impedance off, sequential on, and cross-over on. And after the earphone is inserted, the switch A can start a sequential conduction state to be matched with the codec for earphone state detection, if the detection is abnormal, the switch A can be switched to a cross conduction state for detection again, and finally, a detection result is output to finish earphone detection.

The ground output signal of the switch A is connected into the codec as the backflow of the earphone, and is connected with the magnetic bead under the ground signal pin of the switch A, and the magnetic bead under the magnetic bead is an absolute ground reference ground of the microphone signal and the earphone receiver signal, so that the anti-interference capability of the earphone microphone is enhanced.

The Dp/Dn signal is simultaneously connected to the output terminals of the switch B (second switch) and the switch C (third switch), where the switch B and the switch C are typical tri-state switches capable of meeting three states of high-impedance off, sequential on, and cross-conduction. The output end of the switch C is directly connected to the USB D +/D-interface. The input end of the switch B is connected with the earphone output interface of the codec through a signal, the grounding pin of the switch B is connected with the ground output end of the switch A, and the grounding pin of the switch B is simultaneously pulled back to the earphone reference ground of the codec.

Fig. 6 shows a method for detecting insertion of a Type-C analog headphone of an anti-jamming device shown in fig. 5, including:

s601, inserting a Type-C to 3.5mm earphone patch cord and a 3.5mm earphone;

insert Type-C and change 3.5mm earphone patch cord and four-section Type or syllogic simulation earphone, insert Type-C patch cord earlier, insert the earphone again, or connect earphone and patch cord earlier, insert Type-C patch cord again all can.

S602, when the CC detector detects that the CC pin is low-resistance, the earphone state detection is initiated;

when the patch cord and the earphone are all plugged, the terminal detects that the CC state is a low-impedance grounding characteristic, and judges that the Type-C earphone is plugged;

s603, switching the switch A to a sequential conduction state, and detecting the microphone impedance;

the terminal receives the earphone insertion interruption, initiates microphone detection, switches on and detects microphone impedance according to the sequence of the switch A, reports three-section earphone insertion if the impedance is 0 ohm, keeps the sequence on state of the switch A to complete earphone detection if the detected impedance is normal, reports four-section earphone insertion, and executes S605, otherwise, executes S604.

S604, switching the switch A to a cross conduction state, and detecting the microphone impedance;

when the microphone impedance is detected to be abnormal in S603, the method enters S604, an interruption control switch A is initiated to a cross conduction mode, the microphone impedance is detected again, if the impedance is normal, the cross conduction state of the switch A is maintained to complete the earphone detection, the four-section earphone insertion is reported, and S605 is executed; if the impedance is still detected to be abnormal, the upper feedback earphone state is abnormal, and S606 is executed.

S605, completing the path configuration of the earphone;

and D, according to the conduction sequence of the normal earphone state configuration switch A reported in the step S603 or S604, keeping the switch B conducted and keeping the switch C disconnected, and completing the channel configuration of the analog earphone.

And S606, turning off all the switches B and C.

And S604, reporting that the earphone is abnormal, neglecting the insertion of the earphone, and disconnecting the switch B and the switch C.

In practical application, codes are written in software of a terminal to complete detection logic, CC detection interruption is used as a primary judgment standard for active insertion and extraction of an earphone, a default state is kept if earphone microphone detection can be completed after a switch A is sequentially conducted in an earphone insertion state, the switch A needs to be switched to a cross conduction state to detect the earphone microphone state again if detection cannot be completed, and earphone insertion actions are ignored when the switch A detects that the earphone microphone is abnormal in both conduction sequences.

The anti-interference method and device that this embodiment provided accord with Type-C agreement completely, support the positive and negative interpolation of Type-C interface, can realize syllogic earphone, four-segment American standard earphone simultaneously, four-segment European standard earphone multiform earphone.

EXAMPLE six

In the embodiment of the present invention, the anti-interference apparatus and the anti-interference method provided in the embodiment of the present invention are further described in a specific call scenario, where an inserted earphone is a 3.5mm earphone as an example.

The anti-interference device is shown in fig. 7, and comprises an earphone, a USB Type-C adapter and a terminal,

the terminal DETECTs the level of the CC/VCONN pin through CC detection DETECT to judge whether the earphone is accessed currently.

When the earphone is connected to the terminal through the USB Type-C adapter, a microphone MIC of the earphone uses a microphone to collect audio signals as microphone input information to be sent to a pin SUB1/SUB2 of the terminal through the USBType-C adapter, wherein one pin of the SUB1/SUB2 inputs the microphone input signals and the other pin is a microphone ground signal which comprises an interference signal based on the inserted positive direction. The Left channel Left and the Right channel Right are connected with a Left channel Left/Right channel Right pin of the terminal through a Dp/Dn pin of a USB Type-C adapter so as to receive a Left channel signal PHP L and a Right channel signal PHP R which are sent through the Left channel Left/Right channel Right pin. When the adapter is a two-to-one adapter, the terminal is connected with the USB D +/USB D-of the AP through a Dp/Dn pin of the USBType-C adapter so as to transmit a USB signal.

Wherein pin SUB1/SUB2 is connected to the differential amplifier in the codec through switch A, pin Dp/Dn is connected to the two headphone amplifiers of the codec through switch B, and pin Dp/Dn is connected to switch C through switch B. The ground output end of the switch A is connected with the ground end of the switch A and is MIC _ GND.

Fig. 8 shows an anti-interference method based on the anti-interference device shown in fig. 7, which includes:

s801, carrying out communication through the inserted Type-C analog earphone;

insert Type-C and change 3.5mm earphone patch cord and four-section Type simulation earphone, call the phone after accomplishing the earphone discernment. During communication, an antenna radiation signal carrying a voice signal is connected into signal lines of a microphone input signal MIC _ OUT, a microphone ground signal MIC _ GND, a Left sound channel signal Left and a Right sound channel signal Right in series along current sound of a microphone of the earphone in a coupling mode; the MIC _ OUT and the MIC _ GND include interference signals received by the earphone microphone.

S802, the microphone signal and the interference signal offset the interference signal through a differential operational amplifier;

and the interference signal received by the earphone microphone finally enters the MIC _ P path of the codec through the MIC _ OUT and the MIC _ GND through the switch A. And synchronously pulling back the interference signal on the MIC _ GND to the codec, and finally inputting the interference signal and the MIC _ P signal into a differential amplifier, wherein the interference signal is finally counteracted by the differential amplifier, and the signal output by the differential amplifier filters the interference signal to be small enough. Where MIC _ P is a signal input to the positive pole of the differential amplifier in the codec, MIC _ GND is a signal input to the negative pole of the differential amplifier in the codec, that is, MIC _ P is the positive pole of the differential acoustic signal input by the codec microphone, and MIC _ GND is the negative pole of the differential signal input by the codec microphone.

S803, the earphone operational amplifier performs interference cancellation processing on the earphone output signal based on the ground reference signal;

the interference signal received by the earphone receiver passes through LEFT and RIGHT. GND three lines finally enter HPH _ L and HPH _ R of the codec through a switch B, in the embodiment, the switch B and the switch A are placed together, the ground of the switch B and the MIC _ GND of the switch A are connected together, meanwhile, the MIC _ GND signal of the switch A is pulled back to the codec through the HPH _ REF, the ground reference signal of the earphone operational amplifier inside the codec is input, the operational amplifier taking the HPH _ REF as the reference is finally output to the HPH _ L, and the signal of the HPH _ R can form a reverse signal equal to the MIC _ GND in quantity, so that the interference of the earphone line in series can be counteracted.

Through the steps of S801-S803, the anti-interference effect of the Type-C analog earphone in the call process can be effectively realized.

In practical application, in hardware layout, the switch a and the switch B can be placed close together, and the ground pin of the switch B is connected to the GND output pin of the switch a, and the GND output signal needs to be fed back into the codec.

In the embodiment of the invention, the interference signal on the earphone microphone is eliminated in a differential signal cancellation mode, the output signal on the HPH _ L/HPH _ R sound channel is processed by taking the HPH _ REF reference signal as reference in a software mode to cancel the interference signal on the earphone channel, and the three aspects of earphone patch cord design, analog circuit design and software algorithm design are improved simultaneously, so that the audio performance index and the anti-interference capability of the Type-C analog earphone are improved to the maximum extent.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. An apparatus for resisting interference, the apparatus comprising: the earphone comprises a Type-C interface, a first switch for transmitting a microphone signal, a second switch for transmitting an earphone signal and a first processor;

2. The apparatus of claim 1, wherein the microphone signal pins of the Type-C interface comprise a first microphone signal pin and a second microphone signal pin; the first microphone signal pin is used for transmitting a microphone input signal, and the second microphone signal pin is used for transmitting a microphone ground signal;

the first microphone signal pin is connected with the first processor through the first switch;

the second microphone signal pin is connected with the ground output end of the first switch;

the ground output end of the first switch is connected with the first processor.

3. The apparatus of claim 2, wherein the first processor comprises a differential amplifier;

the first microphone signal pin is connected with the first input end of the differential amplifier through the first switch;

the ground output end of the first switch is connected with the second input end of the differential amplifier.

4. The apparatus of claim 2, wherein the headphone signal pin comprises a first channel pin and a second channel pin; the first processor comprises a first headphone amplifier and a second headphone amplifier;

the first channel pin is connected with the input end of the first earphone amplifier through the second switch;

and the second channel pin is connected with the input end of the second earphone amplifier through the second switch.

5. The apparatus of claim 4, wherein a ground output of the first switch is connected to a ground reference of the first headphone amplifier and a ground reference of the second headphone amplifier, respectively.

6. The apparatus of claim 4, further comprising a second processor, wherein a level detection pin of the Type-C interface is connected to the second processor, and wherein the level detection pin is used for triggering a headset insertion signal.

7. The apparatus of claim 1, further comprising: a second processor and a third switch for transmitting a USB signal;

the earphone receiver signal pin of the Type-C interface is connected with the second processor through the third switch; the ground of the third switch is connected with the common ground.

8. An anti-interference method applied to the anti-interference device according to any one of claims 1 to 7, the method comprising:

9. The method of claim 8, further comprising:

and taking a microphone ground signal in the microphone signals as a ground signal of the earphone signals.

10. The method of claim 9, further comprising:

respectively taking a mike input signal and the mike ground signal in the mike signals as input signals of a first differential amplifier in the first processor;

and carrying out differential amplification processing on the microphone input signal and the microphone ground signal through the differential amplifier.

11. The method of claim 9, wherein the headphone signal comprises a first channel signal and a second channel signal; the first processor comprises a first headphone amplifier and a second headphone amplifier, the method further comprising:

amplifying the first sound channel signal through the first headphone amplifier;

and amplifying the second channel signal by the second earphone amplifier.

12. The method of claim 11, wherein the amplifying the first channel signal by the first headphone amplifier and the amplifying the second channel signal by the second headphone amplifier comprise:

taking the mike ground signal as a ground reference signal of the first headphone amplifier to amplify the first channel signal;

and taking the mike ground signal as a ground reference signal of the second earphone amplifier to amplify the second channel signal.

13. The method of claim 8, further comprising:

when the level detection pin of the Type-C interface detects the level change, triggering an earphone insertion signal;

sending the headset insertion signal to a second processor.

14. An anti-jamming system, characterized in that the system comprises: a headset, a transducer and a terminal, the terminal comprising the tamper resistant arrangement of any one of claims 1 to 7.

15. The system of claim 14, wherein the earphone socket of the converter is provided with a first detection pin and a second detection pin;

the first detection pin is connected with a level detection pin of a Type-C interface of the converter;

the second detection pin is grounded.