CN105992098A - Audio input circuit and electronic terminal - Google Patents
Audio input circuit and electronic terminal Download PDFInfo
- Publication number
- CN105992098A CN105992098A CN201510050056.2A CN201510050056A CN105992098A CN 105992098 A CN105992098 A CN 105992098A CN 201510050056 A CN201510050056 A CN 201510050056A CN 105992098 A CN105992098 A CN 105992098A
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- China
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- audio
- outfan
- circuit
- bias voltage
- audio input
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Telephone Function (AREA)
- Filters And Equalizers (AREA)
- Amplifiers (AREA)
Abstract
The invention provides an audio input circuit and an electronic terminal. The audio input circuit comprises an audio collecting unit, an audio sampling unit and a bias voltage providing unit. The audio collecting unit is used for collecting an audio signal; the audio sampling unit is used for sampling the audio signal collected by the audio collecting unit, and includes a first audio input end and a second audio input end, wherein the audio collecting unit is connected with the first audio input end through a first line; and the bias voltage providing unit includes a bias voltage input end and a first output end and a second output end which are connected with the bias voltage input end, wherein the first output end is connected to the first line, the second output end is connected to the second audio input end through a second line, the voltage of the second output end is equal to a bias voltage input by the bias voltage input end, and the voltage of the first output end is equal to the difference between the bias voltage input by the bias voltage input end and the voltage of the audio signal. Through the scheme of the invention, the call quality of the electronic terminal is improved.
Description
Technical field
The present invention relates to communication technical field, particularly relate to a kind of audio input circuit and electric terminal.
Background technology
For mobile phone board, because layout is the best or routing problem during printing board PCB design so that
A constant impedance is after all there is, the open cnc of global system for mobile communications between ground reference plane zones of different
The high-power transmitting of system GSM PA produces the burst big current needs of Burst, and this big electric current must pass through
Ground reference plane (being equivalent to an impedance) is back to battery cathode, when this electric current flows through this impedance
A constant pressure drop will be produced.When audio frequency return flow path also uses this paths, this pressure drop will be superimposed upon
In audio signal, thus audio signal is produced Conduction Interference.If as it is shown in figure 1, voicefrequency circuit return
Flow through the return flow path that more GSM PA connects to battery, then audio signal produces Conduction Interference and causes noise.
Microphone input circuit has three kinds, and one is fully differential input circuit, and one is pseudo-differential input circuit,
One is single ended input circuit.Either as the mini microphone MEMS Microphone of hand-held call,
Or as the electret microphone ECM Microphone of earphone call, it is all Single-end output.In order to advise
The problem keeping away single-ended audio input circuit poor anti jamming capability, prior art is designed as pseudo-differential circuit, and
Circuit arranges the voltage regulator components being connected to ground, the problem solving common mode disturbances.But this voltage is adjusted
Joint parts are usually located at the GSM PA RF return path region to battery connector, in this case,
Ground noise, particularly Burst/TDMA/TDD Noise can be coupled to by this voltage regulator components
On voice-frequency channel, thus sampled by audio input port, to noise can be heard when causing conversing, affect sound
The transmission quality of frequency and satisfaction of users.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of audio input circuit and electric terminal, it is possible to solve
The at present audio input circuit of electric terminal, the problem that the transmission quality of audio frequency is the best.
In order to solve above-mentioned technical problem, a kind of audio input circuit of embodiments of the invention offer, wherein,
Including:
Audio collection unit, is used for gathering audio signal；
Audio sample unit, samples for the audio signal being gathered described audio collection unit, bag
Include the first audio input end and the second audio input end；Wherein, described audio collection unit passes through first line
It is connected with described first audio input end；
Bias voltage provides unit, including bias voltage input and connects with described bias voltage input respectively
The first outfan connect and the second outfan, wherein said first outfan is connected in described first line,
Described second outfan passes through the second connection to the second audio input end, and the electricity of described second outfan
The bias voltage that pressure is inputted equal to bias voltage input, the voltage of described first outfan is equal to biased electrical
The difference of the pressure bias voltage that inputted of input and audio signal voltage.
Wherein, described bias voltage provides unit also to include:
First resistance and the second resistance；
Wherein, described first outfan is connected to described bias voltage input by described first resistance；Institute
State the second outfan and be connected to described bias voltage input by described second resistance.
Wherein, described audio input circuit also includes:
First electric capacity, one end is connected in described first line, and the connection being connected with described first line
Hold between described first outfan and the connection end of described first line and described first audio input end,
Other end ground connection；
Second electric capacity, one end is connected on described second circuit, and the connection being connected with described second circuit
Hold between described second outfan and the connection end of described second circuit and described second audio output,
Other end ground connection；
3rd electric capacity, is connected across between described first line and described second circuit, and one end is connected to described
One electric capacity, the other end is connected to described second electric capacity.
Wherein, described first line includes:
4th electric capacity, one end is connected with described first electric capacity, and the other end is connected with described first audio input end.
Wherein, described second circuit includes:
5th electric capacity, one end is connected with described 3rd electric capacity, and the other end is connected with described second audio input end.
Wherein, described first line also includes:
Inductance element, one end is connected with described audio collection unit, and the other end is connected with described first outfan.
Wherein, described audio collection unit is connected to ground also by tertiary circuit.
In order to solve above-mentioned technical problem, embodiments of the invention also provide for a kind of electric terminal, wherein, bag
Include audio input circuit as above.
Having the beneficial effect that of the technique scheme of the present invention:
Second outfan, by being connected in first line by the first outfan, is connected to by the solution of the present invention
On second circuit so that the voltage of the second outfan provides the bias voltage of unit offer for bias voltage,
During call, the voltage of the first outfan is the difference of bias voltage and audio signal voltage.Due to the first output
The voltage of end and the voltage difference of the second outfan are audio signal voltage, unrelated with bias voltage.This audio frequency
Signal is reference voltage as useful signal by selecting bias voltage during audio sample unit sampling, thus avoids
The Conducted Radio Frequency interference introduced because of shared radio frequency return flow path, thus substantially increase the biography of audio signal
Transmission quality, improves the experience satisfaction of user.
Accompanying drawing explanation
Fig. 1 represents electric terminal interior section component placement figure；
Fig. 2 represents the electrical block diagram one of the audio input circuit of the present invention；
Fig. 3 represents the electrical block diagram two of the audio input circuit of the present invention；
Fig. 4 represents the electrical block diagram three of the audio input circuit of the present invention；
Fig. 5 represents the electrical block diagram four of the audio input circuit of the present invention；
Fig. 6 represents the electrical block diagram five of the audio input circuit of the present invention.
Detailed description of the invention
For making the technical problem to be solved in the present invention, technical scheme and advantage clearer, below in conjunction with attached
Figure and specific embodiment are described in detail.
The audio input circuit of the present invention, as in figure 2 it is shown, specifically include that audio collection unit, audio frequency is adopted
Sample unit, bias voltage provides unit, first line and the second circuit.
Wherein, this audio collection unit can be mike or earphone.
Below in conjunction with Fig. 3, the signal between each components and parts in this audio input circuit is transmitted and connects
Relation elaborates.
In first embodiment of the invention, this audio collection unit is a mike, but is not limited to this, it is also possible to
It it is an earphone.The function of this audio collection unit predominantly gathers audio signal；This audio sample unit
The audio signal that this audio collection unit is predominantly gathered by the function of MICAMP is sampled, including
First audio input end MicP and the second audio input end MicN；Wherein, this audio collection unit passes through
First line is connected with this first audio input end MicP.
Bias voltage in this audio input circuit provides unit, including bias voltage input, and with this
The first outfan that bias voltage input connects respectively and the second outfan；Wherein this first outfan connects
To this first line, and the connection end that this first outfan and this first line are connected to form is referred to as first
Connect end；This second outfan is by the second audio input end of the second circuit with this audio sample unit
MicN connects, and the connection end that this second outfan and this second circuit are connected to form is referred to as the second connection
End.In the present embodiment, this bias voltage provides unit also to include: the first resistance R1 and the second resistance R2.
This first outfan is connected with this bias voltage input by this first resistance R1, and this second outfan leads to
Cross this second resistance R2 to be connected with this bias voltage input.
In conjunction with Fig. 3, the voltage of the second outfan be a constant voltage value (be inclined in this embodiment of the invention
Put voltage), when call, owing to mike alternating current, i.e. audio frequency letter are flow through in acoustical signal fluctuating generation
Number electric current, due to the existence of the first resistance R1, produce audio signal voltage, therefore this first outfan
Voltage is one audio signal voltage of superposition in this constant voltage value.The voltage of this first outfan and this is second defeated
The voltage going out end does difference, is by the signal of this audio sample unit sampling, this signal of the solution of the present invention
Being audio signal, this audio signal is selected bias voltage as useful signal during audio sample unit sampling
For reference voltage, thus avoid the Conducted Radio Frequency interference introduced because of shared radio frequency return flow path.
Above-mentioned is to the company between the part components and parts of the audio input circuit in the first embodiment of the present invention
Connect the detailed description of relation, more complete of course for making this circuit, i.e. there are other in view of in circuit
Interference, the existence of the problems such as the most high-frequency common mode disturbances problem, high frequency differential mode interference problem, at this
In the second bright embodiment, the audio input circuit of the present invention as shown in Figure 4, also includes:
First electric capacity C1, the second electric capacity C2 and the 3rd electric capacity C3, these three electric capacity are combined filter electric capacity,
The noise of the high bands such as 900HZ or 2100HZ mainly filtering GSM.Wherein, these three electric capacity
Position relationship in this audio input circuit is described as follows:
This first electric capacity C1 is connected in this first line, and claims the connection being connected to form with this first line
End is the 3rd connection end.3rd connects end first connects between end and this MicP at this, this first electricity
Hold the other end ground connection of C1.
This second electric capacity C2 is connected on this second circuit, and claims the connection being connected to form with this second circuit
End is the 4th connection end.4th connects end second connects between end and this MicN at this, this second electricity
Hold the other end ground connection of C2.
The main function of this first electric capacity C1 and this second electric capacity C2 is the common mode disturbances filtering high band.
3rd electric capacity C3, is connected across between this first line and this second circuit, one end and this first electric capacity C1
Being connected, the other end is connected with this second electric capacity C2.Wherein, the main function of the 3rd electric capacity C3 is filter
Differential mode interference except high band.
Wherein, in order to isolate the direct current signal in audio signal path, prevent direct current signal from entering audio sample
Unit.In the third embodiment of the present invention, as it is shown in figure 5, the first of the audio input circuit of the present invention
Including on circuit: the 4th electric capacity C4, one end is connected with this first electric capacity C1, and the other end is with this MicP even
Connect.
Include on second circuit of the audio input circuit of the present invention: the 5th electric capacity C5, one end with this second
Electric capacity C2 connects, and the other end is connected with this MicN.
The main function of the 4th electric capacity C4 and the 5th electric capacity C5 is for being used for isolating audio signal path
Direct current signal, prevent direct current signal enter audio sample unit.
Wherein, in order to isolate DC influence and the noise in the external world, in the fourth embodiment of the present invention, such as figure
Shown in 6, this first line also including: inductance component L, one end is connected with this mike, the other end with
This first outfan connects.Certainly this mike is connected to ground also by tertiary circuit.
The above is the detailed description of the circuit structure of the audio input circuit to the present invention, below based on the present invention
Circuit structure being explained as follows the principle of the present invention of audio input circuit:
The cardinal principle of the circuit structure of the audio input circuit of the present invention is: the voltage of the first outfan and
The voltage difference of two outfans is audio signal voltage, unrelated with bias voltage.Audio frequency based on the present invention is defeated
The circuit structure entering circuit is as follows to the principle illustration of the present invention:
Mike is as a two-terminal devices, it is assumed that the electric current flow through is I=I0+i；Wherein, I0Permissible
It is not understood as DC bias current, or can be construed to, be to pass through wheat in the case of the peace and quiet not having sound
The electric current of gram wind, it is believed that be invariable.I is then that acoustical signal fluctuating causes stream when call
Cross the alternating current of mike.Ignore the PF level electric capacity and the impact of magnetic bead filtered in circuit, for wheat
The couple input of gram wind, it is believed that be the infinitely great input impedance of ideal amplifier, it is also possible to do not consider
Impact on circuit.As such, it is possible to obtain the first outfan and the voltage expression of the second outfan:
The voltage V of the first outfan+=Vmicbias-R1(I0+i)；
The voltage V of the second outfan-=Vmicbias；Wherein VmicbiasFor bias voltage.
Due to the 4th electric capacity C4 and the existence of the 5th electric capacity C5, finally by the electricity of audio sample unit sampling
Pressure is R1 × i, owing to the voltage of the second outfan is bias voltage, is i.e. a constant voltage value, the first output
The voltage of end is one audio signal voltage of superposition in this constant voltage value, and both differences are audio signal, this sound
Frequently signal is reference voltage as useful signal by selecting bias voltage during audio sample unit sampling, thus keeps away
Exempt from the Conducted Radio Frequency interference introduced because of shared radio frequency return flow path.Compared to prior art, it is not necessary to arrange
The voltage regulator components being connected to ground, it is to avoid ground noise is coupled to audio frequency by this voltage regulator components
On path.Simultaneously as there is ripple on bias voltage, if MicP end and MicN end are all deposited
In Ripple Noise, then, after this noise enters audio sample unit, difference amplifier outfan can deduct noise,
Thus improve signal to noise ratio.
To sum up, the solution of the present invention improves the speech quality of electric terminal.
Embodiments of the invention also provide for a kind of electric terminal, including audio input circuit as above.
It should be noted that this electric terminal is the electric terminal including above-mentioned audio input circuit, above-mentioned sound
Frequently the implementation of the embodiment of input circuit is be applicable to the embodiment of this electric terminal, also can reach identical
Technique effect.
The above is the preferred embodiment of the present invention, it is noted that for the common skill of the art
For art personnel, on the premise of without departing from principle of the present invention, it is also possible to make some improvements and modifications,
These improvements and modifications also should be regarded as protection scope of the present invention.
Claims (8)
1. an audio input circuit, it is characterised in that including:
Audio collection unit, is used for gathering audio signal；
Audio sample unit, samples for the audio signal being gathered described audio collection unit, bag
Include the first audio input end and the second audio input end；Wherein, described audio collection unit passes through first line
It is connected with described first audio input end；
Bias voltage provides unit, including bias voltage input and connects with described bias voltage input respectively
The first outfan connect and the second outfan, wherein said first outfan is connected in described first line,
Described second outfan passes through the second connection to the second audio input end, and the electricity of described second outfan
The bias voltage that pressure is inputted equal to bias voltage input, the voltage of described first outfan is equal to biased electrical
The difference of the pressure bias voltage that inputted of input and audio signal voltage.
Audio input circuit the most according to claim 1, it is characterised in that described bias voltage carries
Also include for unit:
First resistance and the second resistance；
Wherein, described first outfan is connected to described bias voltage input by described first resistance；Institute
State the second outfan and be connected to described bias voltage input by described second resistance.
Audio input circuit the most according to claim 1, it is characterised in that described audio frequency input electricity
Road also includes:
First electric capacity, one end is connected in described first line, and the connection being connected with described first line
Hold between described first outfan and the connection end of described first line and described first audio input end,
Other end ground connection；
Second electric capacity, one end is connected on described second circuit, and the connection being connected with described second circuit
Hold between described second outfan and the connection end of described second circuit and described second audio output,
Other end ground connection；
3rd electric capacity, is connected across between described first line and described second circuit, and one end is connected to described
One electric capacity, the other end is connected to described second electric capacity.
Audio input circuit the most according to claim 3, it is characterised in that in described first line
Including:
4th electric capacity, one end is connected with described first electric capacity, and the other end is connected with described first audio input end.
Audio input circuit the most according to claim 3, it is characterised in that on described second circuit
Including:
5th electric capacity, one end is connected with described second electric capacity, and the other end is connected with described second audio input end.
Audio input circuit the most according to claim 1, it is characterised in that in described first line
Also include:
Inductance element, one end is connected with described audio collection unit, and the other end is connected with described first outfan.
Audio input circuit the most according to claim 1, it is characterised in that described audio collection list
Unit is connected to ground also by tertiary circuit.
8. an electric terminal, it is characterised in that include the sound as described in any one of claim 1 to 7
Frequently input circuit.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510050056.2A CN105992098B (en) | 2015-01-30 | 2015-01-30 | Audio input circuit and electronic terminal |
| PCT/CN2015/091679 WO2016119487A1 (en) | 2015-01-30 | 2015-10-10 | Audio input circuit and electronic terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510050056.2A CN105992098B (en) | 2015-01-30 | 2015-01-30 | Audio input circuit and electronic terminal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105992098A true CN105992098A (en) | 2016-10-05 |
| CN105992098B CN105992098B (en) | 2020-03-10 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510050056.2A Active CN105992098B (en) | 2015-01-30 | 2015-01-30 | Audio input circuit and electronic terminal |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN105992098B (en) |
| WO (1) | WO2016119487A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112153182A (en) * | 2019-06-28 | 2020-12-29 | 西安中兴新软件有限责任公司 | Audio circuit and mobile terminal with same |
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| CN201307878Y (en) * | 2008-11-05 | 2009-09-09 | 宇龙计算机通信科技(深圳)有限公司 | Analog audio input circuit, mobile communication terminal and earphone |
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| US7882743B2 (en) * | 2005-12-20 | 2011-02-08 | Broadcom Corp. | Method and system for noise dosimeter |
| CN201479352U (en) * | 2009-07-29 | 2010-05-19 | 比亚迪股份有限公司 | Audio adjusting circuit of earphone sender |
| CN103731776A (en) * | 2012-10-15 | 2014-04-16 | 成都众易通科技有限公司 | Audio circuit used for GPS voice control system |
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2015
- 2015-01-30 CN CN201510050056.2A patent/CN105992098B/en active Active
- 2015-10-10 WO PCT/CN2015/091679 patent/WO2016119487A1/en active Application Filing
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101175101A (en) * | 2006-11-02 | 2008-05-07 | 联想移动通信科技有限公司 | Sound processing method and device for mobile phone microphone |
| CN201307878Y (en) * | 2008-11-05 | 2009-09-09 | 宇龙计算机通信科技(深圳)有限公司 | Analog audio input circuit, mobile communication terminal and earphone |
| US20110018616A1 (en) * | 2009-07-22 | 2011-01-27 | Kontel Data System Limited | Charge pump circuit |
| CN102026063A (en) * | 2010-11-26 | 2011-04-20 | 中兴通讯股份有限公司 | Pseudo differential audio input circuit and installation method thereof |
| CN203788450U (en) * | 2014-04-18 | 2014-08-20 | 青岛海信移动通信技术股份有限公司 | Current hum restraining circuit of mobile terminal and mobile terminal |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112153182A (en) * | 2019-06-28 | 2020-12-29 | 西安中兴新软件有限责任公司 | Audio circuit and mobile terminal with same |
| WO2020259143A1 (en) * | 2019-06-28 | 2020-12-30 | 西安中兴新软件有限责任公司 | Audio circuit and mobile terminal provided with audio circuit |
| CN112153182B (en) * | 2019-06-28 | 2022-04-19 | 西安中兴新软件有限责任公司 | Audio circuit and mobile terminal with same |
| US11895469B2 (en) | 2019-06-28 | 2024-02-06 | Xi'an Zhongxing New Software Co. Ltd. | Audio circuit and mobile terminal provided with audio circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2016119487A1 (en) | 2016-08-04 |
| CN105992098B (en) | 2020-03-10 |
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