CN105959876B - Microphone amplifier circuit - Google Patents
Microphone amplifier circuit Download PDFInfo
- Publication number
- CN105959876B CN105959876B CN201610388433.8A CN201610388433A CN105959876B CN 105959876 B CN105959876 B CN 105959876B CN 201610388433 A CN201610388433 A CN 201610388433A CN 105959876 B CN105959876 B CN 105959876B
- Authority
- CN
- China
- Prior art keywords
- transistor
- microphone amplifier
- amplifier circuit
- output end
- grid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
- 239000003990 capacitor Substances 0.000 claims abstract description 12
- 239000013078 crystal Substances 0.000 claims description 3
- 238000005516 engineering process Methods 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- 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
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/56—Modifications of input or output impedances, not otherwise provided for
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2420/00—Details of connection covered by H04R, not provided for in its groups
- H04R2420/01—Input selection or mixing for amplifiers or loudspeakers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Amplifiers (AREA)
Abstract
The present invention provides a kind of microphone amplifier circuits, including input, output end, the first transistor, second transistor, third transistor, the 4th transistor, the first current source, the second current source and capacitor.Compared with the relevant technologies, microphone amplifier circuit provided by the invention improves phase compensation by one the 4th transistor of setting, thus, even if load capacitance is larger, it could be used that lesser capacitor carries out phase compensation, so that microphone amplifier circuit has lower output impedance.Simultaneously by the 4th transistor of addition but also microphone amplifier circuit can export outward high current and inwardly receive high current, output push-pull type electric current is realized.
Description
[technical field]
The present invention relates to a kind of microphone circuit more particularly to a kind of microphone amplifier circuits.
[background technique]
Microphone amplifier circuit mainly includes MEMS sensor and ASIC (Application-Specific
Integrated Circuit, specific integrated circuit), the two be electrically connected with realize by voice signal be converted into electric signal to
Realize the function of microphone.
However, in the related art, the output end of microphone amplifier circuit is generally used for output high current, due to connection
The load of output end is variation, it is therefore desirable to which the output end can also receive inside high current.In the related art, it loads
Capacitor generally can not be excessive, and phase margin can be deteriorated, and to keep phase margin, when load capacitance is excessive, need one it is larger
Capacitor do phase compensation, this causes the output impedance of microphone amplifier circuit generally large again, influences microphone amplification
The size of the electric current of device circuit output.
Therefore, it is necessary to provide the novel microphone amplifier circuit of one kind to solve the above problems.
[summary of the invention]
The purpose of the present invention is to provide a kind of microphone amplifier circuit, can export outward high current and to
Interior reception high current, and output impedance is lower.
Technical scheme is as follows: a kind of microphone amplifier circuit, including input, output end, first crystal
Pipe, second transistor, third transistor, the 4th transistor, the first current source, the second current source and capacitor, described first is brilliant
The grid of body pipe connects the input terminal, and the source electrode of the first transistor connects the output end, the first transistor
Drain electrode is grounded by first current source, and the grid of the second transistor is connect with the drain electrode of the first transistor, institute
The drain electrode for stating second transistor is connected to operating voltage by second current source, and the source electrode of the second transistor is grounded,
The drain electrode of the third transistor is connected to operating voltage, and the source electrode of the third transistor connects the output end, and described the
The grid of three transistors is connect with the drain electrode of the second transistor, the grid and the second transistor of the 4th transistor
Grid connect and be connected to together the drain electrode of the first transistor, the source electrode of the 4th transistor is grounded, the 4th crystal
The drain electrode of pipe is connect with the output end, and the capacitance connection is in the source electrode of the second transistor and the grid of third transistor
Between.
Preferably, the first transistor is PMOS tube.
Preferably, the second transistor, third transistor and the 4th transistor use NMOS tube.
Compared with the relevant technologies, microphone amplifier circuit provided by the invention improves phase by the 4th transistor of setting
Position compensation, thus, even if load capacitance is larger, it could be used that lesser capacitor carries out phase compensation, so that microphone amplifier
Circuit has lower output impedance, while making microphone amplifier circuit that can export high current outward and to inscribed
High current is received, output push-pull type electric current is realized.
[Detailed description of the invention]
To describe the technical solutions in the embodiments of the present invention more clearly, make required in being described below to embodiment
Attached drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the invention, for
For those of ordinary skill in the art, without creative efforts, it can also be obtained according to these attached drawings other
Attached drawing, in which:
Fig. 1 is the circuit structure diagram of inventive microphone amplifier circuit, and in the circuit, the electric current of output end is to flow into
's；
Fig. 2 is the circuit structure diagram of inventive microphone amplifier circuit, and in the circuit, the electric current of output end is outflow
's.
[specific embodiment]
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that the described embodiments are merely a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts all other
Embodiment shall fall within the protection scope of the present invention.
Fig. 1 and Fig. 2 are please referred to, Fig. 1 is the circuit structure diagram of inventive microphone amplifier circuit, shows output end
Electric current is to flow into.Fig. 2 is the circuit structure diagram of inventive microphone amplifier circuit, and the electric current for showing output end is outflow
's.
In the present embodiment, microphone amplifier circuit includes input terminal Vin, output end Vout, the first transistor M1, second
Transistor M2, third transistor M3, the 4th transistor M4, for providing the first current source I of reference current1, for providing benchmark
Second current source I of electric current2And capacitor C1.The microphone amplifier circuit passes through the input terminal VinReceive extraneous telecommunications
Number, electric signal described in the microphone amplifier processing of circuit, and by the treated electric signal by the output end Vout
Output.Output end VoutOn be additionally provided with by load resistance RLWith load capacitance CLThe analogue load circuit of composition.Output end Vout
In driving load resistance RLWhen, the electric current for flowing through output end is recommended.As shown in Figure 1, output end VoutIt can receive by loading
Resistance RLThe high current I poured intoout, the high current is by the 4th transistor M4It receives.As shown in Fig. 2, third transistor M3It can mention
For high current IoutTo drive load resistance RL。
Specifically, the first transistor M1Grid connect the input terminal VinTo receive extraneous electric signal, described first is brilliant
Body pipe M1Source electrode connect the output end VoutTo export the extraneous electric signal by amplification, to realize microphone amplifier
Impedance transformation, i.e. input impedance is big, and output impedance is small, the first transistor M1Drain electrode pass through the first current source I1
Ground connection.
The second transistor M2Grid and the first transistor M1Drain electrode connection, the second transistor M2's
Drain electrode is through the second current source I2It is connected to operating voltage VDD, the second transistor M2Source electrode ground connection.
The third transistor M3Drain electrode be connected to operating voltage VDD, the third transistor M3Source electrode and described the
One transistor M1Source electrode connect and be connected to the output Vout, the third transistor M3Grid and the second transistor M2
Drain electrode connection.
The 4th transistor M4Grid and the second transistor M2Grid connection, the 4th transistor M4's
Source electrode and the second transistor M2Source electrode connect and ground, the 4th transistor M4Drain electrode and the output end VoutEven
It connects.
The capacitor C1One end is connected to the third transistor M3Grid, the other end is connected to the second transistor
M2Source electrode, and with second transistor M2Source electrode be grounded together.The capacitor C1For carrying out phase compensation.
The second transistor M2Drain electrode and the third transistor M3Grid tie point be the first tie point V1,
The second transistor M2Grid and the first transistor M1Drain electrode tie point be the second tie point V2, pass through setting
The 4th transistor M4, can provide from the second tie point V2, the 4th transistor M4To the output end Vout's
One negative-feedback, the negative-feedback are improved from the second tie point V2, second transistor M2, the first tie point V1To the output end
VoutThe phase compensation of this negative-feedback.Thus, even if the load capacitance CLIt is larger, such as 2nF, it still can be used smaller
Capacitor C1Carry out phase compensation.In addition, due to more from the second tie point V2, the 4th transistor M4To output end Vout's
Negative-feedback, so that the output impedance of the microphone amplifier circuit becomes lower.
Since PMOS tube has lower flicker noise with respect to NMOS tube, the first transistor M in the present embodiment1
Using PMOS tube.
The second transistor, third transistor and the 4th transistor use NMOS tube.
In the present embodiment, the first current source I1, the second current source I2For can provide needs current value device.
The second transistor M2Quiescent current ID2By the second current source I2Definition.The 4th transistor M4's
Quiescent current ID4By the second current source I2Pass through the second transistor M2With the 4th transistor M4The current mirror of composition
To define.As load resistance RLWhen variation, need to input biggish load current I to the microphone amplifier circuitoutWhen,
The first transistor M1Electric current it is constant, the electric current having more is by the 4th transistor M4It receives, is recommended to realize output
Formula electric current.
Compared with the relevant technologies, microphone amplifier circuit provided by the invention passes through the 4th transistor M of setting4To improve
Phase compensation, thus, even if load capacitance CLIt is larger, it could be used that lesser capacitor C1Phase compensation is carried out, so that microphone is put
Big device circuit has lower output impedance, at the same make microphone amplifier circuit can export outward high current and to
Interior reception high current realizes output push-pull type electric current.
Above-described is only embodiments of the present invention, it should be noted here that for those of ordinary skill in the art
For, without departing from the concept of the premise of the invention, improvement can also be made, but these belong to protection model of the invention
It encloses.
Claims (1)
1. a kind of microphone amplifier circuit, which is characterized in that including input, output end, the first transistor, the second crystal
Pipe, third transistor, the 4th transistor, the first current source, the second current source and capacitor；
The first transistor is PMOS tube, and the second transistor, third transistor and the 4th transistor use NMOS tube；
The grid of the first transistor connects the input terminal, and the source electrode of the first transistor connects the output end, institute
The drain electrode for stating the first transistor is grounded by first current source；
The grid of the second transistor is connect with the drain electrode of the first transistor, and the drain electrode of the second transistor passes through institute
It states the second current source and is connected to operating voltage, the source electrode ground connection of the second transistor；
The drain electrode of the third transistor is connected to operating voltage, and the source electrode of the third transistor connects the output end, institute
The grid for stating third transistor is connect with the drain electrode of the second transistor；
The grid of 4th transistor connect with the grid of the second transistor and is connected to the leakage of the first transistor together
Pole, the source electrode ground connection of the 4th transistor, the drain electrode of the 4th transistor are connect with the output end；
The capacitance connection is between the source electrode of the second transistor and the grid of third transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610388433.8A CN105959876B (en) | 2016-06-03 | 2016-06-03 | Microphone amplifier circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610388433.8A CN105959876B (en) | 2016-06-03 | 2016-06-03 | Microphone amplifier circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105959876A CN105959876A (en) | 2016-09-21 |
| CN105959876B true CN105959876B (en) | 2019-07-12 |
Family
ID=56907611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610388433.8A Active CN105959876B (en) | 2016-06-03 | 2016-06-03 | Microphone amplifier circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105959876B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7598814B1 (en) * | 2002-09-11 | 2009-10-06 | Marvell International Ltd. | Method and apparatus for an LNA with high linearity and improved gain control |
| CN102474224A (en) * | 2009-07-13 | 2012-05-23 | 索尼爱立信移动通讯有限公司 | Amplifier stage |
| CN105024653A (en) * | 2014-05-02 | 2015-11-04 | 思睿逻辑国际半导体有限公司 | Low noise amplifier for MEMS capacitive transducers |
| CN105515536A (en) * | 2015-12-03 | 2016-04-20 | 瑞声声学科技(深圳)有限公司 | Rail-to-rail amplifier |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITTO20090495A1 (en) * | 2009-06-30 | 2011-01-01 | St Microelectronics Srl | PREAMPLIFIER CIRCUIT FOR A CAPACITIVE MICRO-ELECTROMECHANICAL ACOUSTIC TRANSDUCER |
-
2016
- 2016-06-03 CN CN201610388433.8A patent/CN105959876B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7598814B1 (en) * | 2002-09-11 | 2009-10-06 | Marvell International Ltd. | Method and apparatus for an LNA with high linearity and improved gain control |
| CN102474224A (en) * | 2009-07-13 | 2012-05-23 | 索尼爱立信移动通讯有限公司 | Amplifier stage |
| CN105024653A (en) * | 2014-05-02 | 2015-11-04 | 思睿逻辑国际半导体有限公司 | Low noise amplifier for MEMS capacitive transducers |
| CN105515536A (en) * | 2015-12-03 | 2016-04-20 | 瑞声声学科技(深圳)有限公司 | Rail-to-rail amplifier |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105959876A (en) | 2016-09-21 |
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