CN108769872A - Earphone Dolby circuit - Google Patents

Abstract

The present invention provides a kind of earphone Dolby circuit, and signal receives transmitting module, including antenna and LC match circuits；Audio Input Modules, including audio input circuit and frequency switch circuit；Audio output module, including noise reduction control circuit and the audio output circuit with the electric connection of noise reduction control circuit；Voice input module includes the voice input signal for acquiring user；Noise measuring module, including feedforward input circuit and rear feed input circuit；Master control chip, signal receive transmitting module, voice input module and audio output module and are electrically connected with Master control chip；Noise reduction process chip, Master control chip, Audio Input Modules, audio output module and noise measuring module are electrically connected with noise reduction process chip, the present invention passes through the adaptability operation on Master control chip and noise reduction process chip, to control audio output module output and the noise opposite in phase Frequency rates sound wave identical with energy that noise measuring module detects, to achieve the purpose that eliminate noise.

Description

Earphone Dolby circuit

Technical field

The present invention relates to electronic circuit technology field, more particularly to a kind of earphone Dolby circuit.

Background technology

With the continuous development of electronic product consumption market, more and more people are listened to high using earphone in daily lifeThe music of quality.However, the noise pollution in city is increasingly severe, in outdoor application common headphones earplug, volume can only be improvedNoise was covered, beautiful music so cannot be not only enjoyed, also has a great impact to one's own listening, you are perhaps veryAuditory fatigue will be felt soon.At this point, if it is desired to the music world is quietly enjoyed, then noise cancelling headphone is likely to become best choosingIt selects.

In existing earphone production process, the noise cancellation generally used is passive type noise reduction, such as commercially available earPlug, earmuff etc..Its principle, to be isolated and absorb the principle of noise, is hindered using external hard plastic material and internal packing materialWhen extraneous noise enters ear, especially even more apparent to the noise reduction of high frequency noise, this is also that present noise suppression is most normalThe method used.Although Ran Er , this kind noise reduction modes realize be easy, for 800Hz or more low-frequency low frequency noises, ifThis passive type noise abatement is applied, needs to bear a large amount of equipment cost and material weight, passive type noise reduction mode is then at this timeActual benefit, and the mode of passive type noise reduction are lost, while inhibiting noise, can also obstruct user's talkSound, this is also one of major defect of passive type.

Invention content

Based on this, the purpose of the present invention is to provide a kind of earphone Dolby circuits using active noise reduction.

A kind of earphone Dolby circuit, including：

Signal receives transmitting module, including antenna and the LC match circuits with antenna electric connection, the signal connectTransmitting module is received to send and receive for signal in earphone communication process；

Audio Input Modules, including audio input circuit and the Audio conversion electricity with audio input circuit electric connectionRoad, acquisition of the Audio Input Modules for audio signal on the earphone；

Audio output module, including noise reduction control circuit and the audio output electricity with noise reduction control circuit electric connectionRoad, output of the audio output module for audio signal on the earphone；

Voice input module includes the voice input signal for acquiring user；

Noise measuring module, including feedforward input circuit and rear feed input circuit, the noise measuring module is for detectingAnd acquire the noise signal of the earphone local environment；

Master control chip, it is equal that the signal receives transmitting module, the voice input module and the audio output moduleIt being electrically connected with the Master control chip, the Master control chip is used for the on off state according to the noise reduction control circuit, withThe corresponding transmission for controlling signal in the voice input module and the audio output module；

Noise reduction process chip, the Master control chip, the Audio Input Modules, the audio output module and described makes an uproarSound detection module is electrically connected with the noise reduction process chip, and the noise reduction process chip is used for according to the noise measuring mouldThe testing result of block, to correspond to the opposite inhibition sound wave of output phase.

Above-mentioned earphone Dolby circuit, by the adaptability operation on the Master control chip and the noise reduction process chip,To control the noise opposite in phase , Frequency rates and energy phase that the audio output module output is detected with the noise measuring moduleSame sound wave, to achieve the purpose that eliminate noise.Above-mentioned earphone Dolby circuit is compared with passive type noise reduction mode, the earphoneDolby circuit is eliminated with the overlapping of waveform into Row noise by using active noise reduction, i.e., is combined with inhibition sound wave by noise.

Further, the Audio Input Modules include audio input port, it is electrical with the audio input port respectivelyIt is the first resistor of connection, the first zener diode and the second zener diode, concatenated with first zener diode respectivelyFirst capacitance and second resistance, respectively with concatenated second capacitance of second zener diode and 3rd resistor.

Further, the noise reduction control circuit includes the 4th resistance, the with the 4th resistance electric connection the 1stPole pipe, respectively with first triode be electrically connected the 5th resistance and the second triode and respectively with second triodeThe 6th resistance and the 7th resistance being electrically connected.

Further, the audio output circuit include loudspeaker output port, it is electrical with the loudspeaker output port respectivelyThe third zener diode and the 4th zener diode of connection, with the concatenated third capacitance of the third zener diode and with instituteState concatenated 4th capacitance of the 4th zener diode.

Further, the voice input module include MIC, respectively fiveth capacitance in parallel with the MIC, respectively with instituteState concatenated 6th capacitance of the 5th capacitance and the 8th resistance and with concatenated first inductance of the 6th capacitance.

Further, clock circuit and state of charge comparison circuit, the clock electricity are additionally provided on the Master control chipRoad provides clock signal for the Master control chip, and the state of charge comparison circuit is for detecting battery capacity.

Further, the state of charge comparison circuit include third transistor, with the third transistor concatenated theNine resistance, with concatenated tenth resistance of the 9th resistance and with concatenated 7th capacitance of the tenth resistance.

Further, signal amplification circuit, the letter are equipped between the Master control chip and the noise reduction process chipThe output end of number amplifying circuit is electrically connected with the input terminal of the frequency switch circuit.

Further, storage circuit is additionally provided on the Master control chip, the storage circuit includes storage unit and dividesEleventh resistor, twelfth resistor and the thirteenth resistor that do not connect with the storage unit.

Further, the Master control chip is made of CSR8635 chips, and the noise reduction process chip usesAMS3435 chips are made.

Description of the drawings

Fig. 1 is the modular structure schematic diagram for the earphone Dolby circuit that first embodiment of the invention provides；

Fig. 2 is the electrical block diagram between antenna, LC match circuits and bandpass filter in Fig. 1

Fig. 3 is the electrical block diagram between Mic circuits and Master control chip in Fig. 1；

Fig. 4 is the electrical block diagram between filtering & switch voltage-stabilizings output circuit and Master control chip in Fig. 1；

Fig. 5 is the electrical block diagram of L/R audio input circuits in Fig. 1；

Fig. 6 is the electrical block diagram of noise reduction control circuit in Fig. 1；

Fig. 7 is the electrical block diagram of L/R loudspeaker output circuits in Fig. 1；

Fig. 8 is the electrical block diagram of storage circuit in Fig. 1；

Fig. 9 is the structural schematic diagram of noise reduction process chip in Fig. 1；

Figure 10 is the modular structure schematic diagram for the earphone Dolby circuit that second embodiment of the invention provides；

Figure 11 is the electrical block diagram of state of charge comparison circuit in Figure 10；

Following specific implementation mode will be further illustrated the present invention in conjunction with above-mentioned attached drawing.

Specific implementation mode

In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, below in conjunction with the accompanying drawings to the present inventionSpecific implementation mode be described in detail.Several embodiments of the present invention are given in attached drawing.But the present invention can be to be permittedMostly different form is realized, however it is not limited to embodiment described herein.Make on the contrary, purpose of providing these embodiments isIt is more thorough and comprehensive to the disclosure.

It should be noted that when element is referred to as " being fixedly arranged on " another element, it can be directly on another elementOr there may also be elements placed in the middle.When an element is considered as " connection " another element, it can be directly connected toTo another element or it may be simultaneously present centering elements.Term as used herein " vertical ", " horizontal ", " left side "," right side ", "upper", "lower" and similar statement for illustrative purposes only, do not indicate or imply the indicated device or memberPart must have a particular orientation, with specific azimuth configuration and operation, therefore be not considered as limiting the invention.

In the present invention unless specifically defined or limited otherwise, term " installation ", " connected ", " connection ", " fixation " etc.Term shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected；It can be machineTool connects, and can also be electrical connection；It can be directly connected, can also can be indirectly connected through an intermediary two membersConnection inside part.For the ordinary skill in the art, above-mentioned term can be understood in this hair as the case may beConcrete meaning in bright.Term " and or " used herein include the arbitrary of one or more relevant Listed Items andAll combinations.

It please referring to Fig.1 to Fig. 2 and Fig. 9, first embodiment of the invention provides a kind of earphone Dolby circuit 100, including：

Signal receives transmitting module, including antenna 30 and the LC match circuits 31 with the electric connection of the antenna 30, describedSignal receives transmitting module and is sended and received for signal in earphone communication process；

Audio Input Modules, including audio input circuit and the Audio conversion electricity with audio input circuit electric connectionRoad 53, acquisition of the Audio Input Modules for audio signal on the earphone, the audio input circuit is in Fig. 1L/R audio input circuits 55；

Audio output module, including noise reduction control circuit 51 (ANC ON/OFF) and electrical with the noise reduction control circuit 51The audio output circuit 54 (output of L/R loudspeaker) of connection, the audio output module on the earphone audio signal it is defeatedGo out；

Voice input module 40 (Mic circuits), includes the voice input signal for acquiring user；

Noise measuring module, including feedforward input circuit 60 and rear feed input circuit 62, the noise measuring module are used forDetect and acquire the noise signal of the earphone local environment；

Master control chip 10, the Master control chip 10 are made of CSR8635 chips, and the signal receives transmitting mouldBlock, the voice input module 40 and the audio output module are electrically connected with the Master control chip 10, the master controlCoremaking 10 controls the voice input module 40 and institute for the on off state according to the noise reduction control circuit 51 with correspondingState the transmission of signal in audio output module；

Noise reduction process chip 50, the noise reduction process chip 50 are made of AMS3435 chips, the Master control chip10, the Audio Input Modules, the audio output module and the noise measuring module with the noise reduction process chip 50It is electrically connected, the noise reduction process chip 50 is used for the testing result according to the noise measuring module, to correspond to output phaseOpposite inhibition sound wave.

Specifically, referring to Fig. 3, the voice input module 40 include MIC, it is the in parallel with the MIC the 5th electric respectivelyHold C17, respectively with the concatenated 6th capacitance C16 and the 8th resistance R12 of the 5th capacitance C17 and with the 6th capacitance C16Concatenated first inductance L6, the MIC are microphone, and the MIC is used for the identification of the voice signal of front end user, and then effectivelyFacilitate in the follow-up earphone and send words step, it is preferred that the VCC pin of MIC described in the present embodiment and the described 8thResistance R12 is electrically connected, and the G pins of the MIC are connected in series with the 6th capacitance C16, the 5th capacitance C17 respectively,And the resistance value of the 8th resistance R12 is 2.2K, the capacity of the 5th capacitance C17 is 1uf, and the capacity of the 6th capacitance isThe value of 15p, the first inductance L6 are 15nH.

Fig. 4 to Fig. 5 is please referred to, filtering & switch voltage-stabilizing output circuits, the audio are additionally provided on the Master control chip 10Input module includes audio input port J17, the first resistor R60 being electrically connected respectively with the audio input port J17,One zener diode VR5 and the second zener diode VR6, respectively with the concatenated first capacitance C136 of first zener diodeAnd second resistance R4, respectively with the concatenated second capacitance C137 of second zener diode and 3rd resistor R3, described firstThe resistance value of resistance R60 is 100R, and the resistance value of the second resistance R4 is 150R, and the resistance value of the 3rd resistor R3 is 150R, instituteThe capacity for stating the first capacitance C136 and the second capacitance C137 is 33p, and the first zener diode VR5, describedTwo zener diode VR6, the first capacitance C136, the second capacitance C137, the second resistance R4 and third electricityThe output end of resistance R3 is connected to ground.

Referring to Fig. 6, the noise reduction control circuit 51 includes the 4th resistance R1, is electrically connected with the 4th resistance R4First triode Q3, respectively with the first triode Q3 be electrically connected the 5th resistance R2 and the second triode Q2 and respectively withThe resistance value of the 6th resistance R61 and the 7th resistance R13 that the second triode Q2 is electrically connected, the 4th resistance R1 are 10K,The resistance value of the 5th resistance R2 is 47K, and the resistance value of the 6th resistance R61 is 300K, and the resistance value of the 7th resistance R13 is100K。

Referring to Fig. 7, the audio output circuit include loudspeaker output port, it is electrical with the loudspeaker output port respectivelyThe third zener diode VR3 and the 4th zener diode VR4 of connection and the concatenated thirds of the third zener diode VR3Capacitance C24 and with the concatenated 4th capacitance C25 of the 4th zener diode VR4, the third capacitance C24 and it is described 4th electricityThe capacity of appearance is 10nF, specifically, loudspeaker output port described in the present embodiment include anode port J28 and cathode portJ19, output of the loudspeaker output port for voice on the earphone.

In addition, being equipped with signal amplification electricity between Master control chip 10 described in the present embodiment and the noise reduction process chip 50Road 52 (BT amplifying circuits), the output end of the signal amplification circuit 52 and the input terminal of the frequency switch circuit 53 electrically connectIt connects, the signal amplification circuit 52 is for amplifying the letter that the Master control chip 10 is sent towards the noise reduction process chip 50Number, to improve the stability of signal transmission.

Referring to Fig. 8, being additionally provided with storage circuit 41 on the Master control chip 10, the storage circuit 41 includes that storage is singleMember and eleventh resistor R5, the twelfth resistor R6 and thirteenth resistor R7 to connect respectively with the storage unit, the storageUnit is made of 24C512A chips, the eleventh resistor R5, the twelfth resistor R6 and the thirteenth resistor R7'sResistance value is 2.2K, and the eleventh resistor R5, the twelfth resistor R6 and the thirteenth resistor R7 are electric with the 8thHold C26 series connection, the capacity of the 8th capacitance C26 is 10nF.

Preferably, the WC pins of storage unit described in the present embodiment are connected in series with the eleventh resistor R5, describedThe SCL pins of storage unit are connected in series with the twelfth resistor R6, the SDA pins of the storage unit and the described 13rdResistance R7 is connected in series with

Specifically, the process for using of the present embodiment is, receive process of conversing：After the earphone booting, power supply is to main controlChip 10 is powered, after the interaction matching of terminal device & hosts, collect call terminal device, and signal is sent out, believedNumber receive transmitting module receive, through Master control chip 10 handle, if under noise reduction ANC OFF situations, signal by ESD protection electricityRoad is exported by loudspeaker.

If noise reduction ANC ON, signal amplifies by BT amplifying circuits 52, and noise reduction process is switched to by L/R Yin Pins &BTAfter the processing of device chip 50, parallel detects ambient external noise by the input circuit 60 that feedovers, and is transported to de-noising processorChip 50, after its internal inverting amplifier and the processing of different RC filter networks, by esd protection circuit, with requiredAudio signal be added to loudspeaker, to complete, to environmental noise phase cancellation, to realize the noise reduction process of feedforward.Meanwhile rear feedInput circuit 62 detect loudspeaker output noise in de-noising processor chip 50 inverting amplifier and different RC filterIt after network processes, by esd protection circuit, is mixed with required audio signal, be added to loudspeaker, and carrying out phase to noise supportsDisappear, to reach noise reduction purpose, this measure completes call and listens to process.

Words process is sent in call：After the earphone booting, power supply powers to Master control chip 10, sound pick-up MIC pickups to instituteAfter needing audio signal, after filtering and anti-jamming circuit, it is transported to Master control chip 10 and is handled, and pass through bandpass filteringDevice 32 is equipped with lattice network, and terminal device is arrived in antenna transmitting, and words process is sent in completion.

Hearing process：L/R voicefrequency circuit input audio signals are entered by switching circuit (L/R Yin Pins &BT switchings)De-noising processor chip, at this time if in the case that ANC is closed, audio signal exports after anti-jamming circuit from L/R loudspeaker.

If in the case of ANC ON, signal switches by L/R Yin Pins &BT, arrives after ESD anti-interference protective circuitsAfter de-noising processor chip processing, parallel rear feed module detects in the noise signal to de-noising processor chip of loudspeaker outputInverting amplifier carry out Phase Processing and signal amplification, and by different RC filter networks processing after, pass through ESD protection electricityRoad is added to loudspeaker with required audio signal, in this way, for noise and the antiphase that detects of rear feed module from signalThe mixing of noise signal, superposition, to reach noise reduction purpose, this measure completes audition and listens to process.

Preferably, the earphone Dolby circuit 100 further includes instruction control circuit 34, and described instruction control circuit 34 is used forWith software interact, by instruction arrive Master control chip 10, to for user realize volume+, volume-and switching on and shutting down, phoneIt answers, phone terminates, the functions such as music.

The earphone Dolby circuit 100 further includes LED circuit 22, is used under the action of software and Master control chip 10,To different instructions, state provides different dispaly states.

The earphone Dolby circuit 100 further includes power module 20, is filled to battery by Master control chip 10 for USBElectricity, and overvoltage protection is provided, when Master control chip 10 detects that voltage is full of, it will one signal of feedback stops to power circuitIt only charges, and 22 dispaly state of indication LED circuit is converted.Overshoot, if external voltage because certain factor increase, power unitOvervoltage protection will play the role of critical, to protected host, eliminate safe hidden trouble.

Above-mentioned earphone Dolby circuit 100 passes through the adaptation on the Master control chip 10 and the noise reduction process chip 50Property operation, to control the noise opposite in phase , Frequency rates that audio output module output is detected with the noise measuring moduleSound wave identical with energy, to achieve the purpose that eliminate noise.Above-mentioned earphone Dolby circuit 100 is compared with passive type noise reduction modeCompared with the earphone Dolby circuit 100 is eliminated with the overlapping of waveform into Row noise by using active noise reduction, i.e., by noise and inhibitionSound wave is combined, if inhibiting the waveform of wave identical as the sonic wave amplitude of desire noise reduction, frequency, and when reverse phase, then can obtain noise reduction effectFruit.

Referring to Fig. 10, the modular structure schematic diagram of the earphone Dolby circuit 100a provided for second embodiment of the invention,The structure of the second embodiment and first embodiment is more or less the same, and difference lies in Master control chip 10 described in the present embodimentOn be additionally provided with clock circuit 21 and state of charge comparison circuit 33, when the clock circuit 21 is that the Master control chip 10 providesClock signal, the state of charge comparison circuit 33 are used under the action of Master control chip 10, are detected to battery capacity, andThe state of LED is indicated, while Master control chip 10 sends out instruction, carries out state quotation.

It is the electrical block diagram of state of charge comparison circuit 33 in Figure 10, the electricity specifically, please referring to Fig.1 1Epidemic situation comparison circuit includes the third transistor Q1 and concatenated 9th resistance R10 of the third transistor Q1 and the 9th electricityHinder the concatenated tenth resistance R126 of R10 and with the concatenated 7th capacitance C149 of the tenth resistance R126, the third transistorThe resistance value of the model BCX51, the 9th resistance R10 of Q1 are 400mR, and the resistance value of the tenth resistance R126 is 200mR, instituteThe capacity for stating the 7th capacitance C149 is 15p, and the output end of the 7th capacitance C149 is connected to ground.

Above embodiment described the technical principles of the present invention, and the description is merely to explain the principles of the invention, andIt cannot be construed to the limitation of the scope of the present invention in any way.Based on the explanation herein, those skilled in the art is not required toOther specific implementation modes of the present invention can be associated by paying performing creative labour, these modes fall within the present invention'sIn protection domain.

Claims (10)

1. a kind of earphone Dolby circuit, which is characterized in that including：

Signal receives transmitting module, including antenna and the LC match circuits with antenna electric connection, the signal receive hairModule is penetrated to send and receive for signal in earphone communication process；

Audio Input Modules, including audio input circuit and the frequency switch circuit with audio input circuit electric connection,Acquisition of the Audio Input Modules for audio signal on the earphone；

Audio output module, including noise reduction control circuit and the audio output circuit with noise reduction control circuit electric connection,Output of the audio output module for audio signal on the earphone；

Voice input module includes the voice input signal for acquiring user；

Noise measuring module, including feedforward input circuit and rear feed input circuit, the noise measuring module is for detecting and adoptingCollect the noise signal of the earphone local environment；

Master control chip, the signal receive transmitting module, the voice input module and the audio output module and instituteMaster control chip electric connection is stated, the Master control chip is used for the on off state according to the noise reduction control circuit, with correspondenceControl the transmission of signal in the voice input module and the audio output module；

Noise reduction process chip, the Master control chip, the Audio Input Modules, the audio output module and noise inspectionIt surveys module to be electrically connected with the noise reduction process chip, the noise reduction process chip is used for according to the noise measuring moduleTesting result, to correspond to the opposite inhibition sound wave of output phase.

2. earphone Dolby circuit according to claim 1, which is characterized in that the Audio Input Modules include audio inputPort, respectively with the audio input port be electrically connected first resistor, the first zener diode and the second zener diode,It connects respectively with second zener diode with concatenated first capacitance of first zener diode and second resistance, respectivelyThe second capacitance and 3rd resistor.

3. earphone Dolby circuit according to claim 1, which is characterized in that the noise reduction control circuit includes the 4th electricityResistance, the first triode being electrically connected with the 4th resistance, the 5th resistance being electrically connected respectively with first triodeAnd second triode and respectively with second triode be electrically connected the 6th resistance and the 7th resistance.

4. earphone Dolby circuit according to claim 1, which is characterized in that the audio output circuit includes loudspeaker outputPort, the third zener diode being electrically connected respectively with the loudspeaker output port and the 4th zener diode, with described theThe concatenated third capacitance of three zener diodes and with concatenated 4th capacitance of the 4th zener diode.

5. earphone Dolby circuit according to claim 1, which is characterized in that the voice input module includes MIC, differenceFiveth capacitance in parallel with the MIC, respectively with concatenated 6th capacitance of the 5th capacitance and the 8th resistance and with describedConcatenated first inductance of six capacitances.

6. earphone Dolby circuit according to claim 1, which is characterized in that be additionally provided with clock electricity on the Master control chipRoad and state of charge comparison circuit, the clock circuit provide clock signal, the state of charge ratio for the Master control chipCompared with circuit for detecting battery capacity.

7. earphone Dolby circuit according to claim 6, which is characterized in that the state of charge comparison circuit includes thirdTriode, with concatenated 9th resistance of the third transistor, with concatenated tenth resistance of the 9th resistance and with described theConcatenated 7th capacitance of ten resistance.

8. earphone Dolby circuit according to claim 1, which is characterized in that the Master control chip and the noise reduction processSignal amplification circuit, the input terminal electricity of the output end of the signal amplification circuit and the frequency switch circuit are equipped between chipProperty connection.

9. earphone Dolby circuit according to claim 1, which is characterized in that be additionally provided with storage electricity on the Master control chipRoad, the storage circuit include storage unit and the eleventh resistor connected respectively with the storage unit, twelfth resistor andThirteenth resistor.

10. earphone Dolby circuit according to claim 1, which is characterized in that the Master control chip uses CSR8635 coresPiece is made, and the noise reduction process chip is made of AMS3435 chips.