CN201813527U - Capacitive microphone circuit - Google Patents
Capacitive microphone circuit Download PDFInfo
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- CN201813527U CN201813527U CN201020531396XU CN201020531396U CN201813527U CN 201813527 U CN201813527 U CN 201813527U CN 201020531396X U CN201020531396X U CN 201020531396XU CN 201020531396 U CN201020531396 U CN 201020531396U CN 201813527 U CN201813527 U CN 201813527U
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- decoupling capacitor
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Abstract
The utility model discloses a capacitive microphone circuit, which comprises a microphone for converting a sound signal into an electric signal, a bias voltage stabilized source for providing stable voltage for the microphone, a bias resistor (R1) of which one end is connected with the bias voltage stabilized source and the other end is connected with the microphone, a stopping condenser (C2) connected with an output end of the microphone, and a first decoupling capacitor (C1) of which one end is connected with an output end of the bias voltage stabilized source and the other end is grounded. The capacitive microphone circuit is characterized by also comprising a second decoupling capacitor (C3) and a third decoupling capacitor (C4), wherein one end of the second decoupling capacitor (C3) is connected to the output end of the bias voltage stabilized source and the other end of the second decoupling capacitor (C3) is grounded; and one end of the third decoupling capacitor (C4) is connected to an output end of the stopping condenser (C2) and the other end of the third decoupling capacitor (C4) is grounded. The capacitive microphone circuit can effectively inhibit 2.4GHz radio-frequency interference, has excellent effect of reducing the bottom noise, and is simple in structure.
Description
Technical field
The utility model relates to a kind of Electret Condencer Microphone circuit, specifically, relates to a kind of Electret Condencer Microphone circuit that can suppress the bluetooth earphone of 2.4Ghz radio frequency interference.
Background technology
Present bluetooth earphone generally uses electret condenser microphone, and its operating circuit as shown in Figure 1.The microphone operating circuit comprises microphone, the biasing stabilized voltage power supply, one end links to each other and biasing resistor R1 that the other end links to each other with microphone with the biasing stabilized voltage power supply, the capacitance C2 that is connected with the output of microphone, one end connects the output of biasing stabilized voltage power supply and the decoupling capacitor C1 of other end ground connection, wherein, microphone is converted to the signal of telecommunication with voice signal, the effect of biasing stabilized voltage power supply is to provide stable voltage to microphone, the biasing stabilized voltage power supply provides bias voltage by biasing resistor R1 to microphone, decoupling capacitor C1 is used to remove the interference noise of biasing output end of stabilized voltage supply, and capacitance C2 exports to Bluetooth chip after the flip-flop of microphone output voltage is isolated.
The signal of telecommunication of electret condenser microphone output is very faint, and voltage is the millivolt level, very easily is subjected to the interference of external environment.Though bluetooth earphone uses the radiofrequency signal of 2.4GHz, but because its distinctive frequency hopping characteristic, microphone and interlock circuit are easier to be subjected to the radio frequency interference of 2.4Ghz, the typical interference is exactly the signal of telecommunication that the microphone interlock circuit can be demodulated into radio frequency interference 800Hz, 1600Hz, because this signal is in the voice frequency range that people's ear can be heard, so the user is when using the bluetooth earphone conversation, microphone can be subjected to this radio frequency interference and make conversation the opposing party hear " " the end make an uproar, speech quality is descended.
Along with present bluetooth earphone be tending towards miniaturization gradually, the distance of its radio-frequency antenna and microphone is near more, radio frequency interference is obvious more.
Therefore, for the microphone of the bluetooth earphone that overcomes above-mentioned prior art in the problem that exists aspect the radio frequency interference, improve the interference free performance of microphone, be to be badly in need of the major issue that solves at present.
The utility model content
Based on above problem, the utility model provides a kind of Electret Condencer Microphone circuit, comprise the microphone that voice signal is converted to the signal of telecommunication, the biasing stabilized voltage power supply of burning voltage is provided for microphone, one end links to each other and biasing resistor (R1) that the other end links to each other with microphone with the biasing stabilized voltage power supply, the capacitance (C2) that is connected with the output of microphone, one end connects the output of biasing stabilized voltage power supply and first decoupling capacitor (C1) of other end ground connection, it is characterized in that, described microphone circuit also comprises: second decoupling capacitor (C3), one end of described second decoupling capacitor (C3) is connected to the output of described biasing stabilized voltage power supply, the other end ground connection of described second decoupling capacitor (C3); The 3rd decoupling capacitor (C4), an end of the 3rd decoupling capacitor (C4) is connected to the output of described capacitance (C2), the other end ground connection of described the 3rd decoupling capacitor (C4).
Preferably, described second decoupling capacitor (C3) and described the 3rd decoupling capacitor (C4) all adopt the ceramic condenser of pico farad level.
More preferably, the electric capacity of described second decoupling capacitor (C3) and described the 3rd decoupling capacitor (C4) is 8.2 pico farads.
Electret Condencer Microphone circuit of the present utility model is primarily aimed at the bluetooth earphone design, by in the bluetooth earphone microphone circuit, increasing the decoupling capacitor of two pico farad levels, output from the feeder ear of microphone to microphone all suppresses the radio frequency interference of 2.4Ghz, has the effect of making an uproar at the bottom of the excellent reduction, in addition, also has advantage simple in structure, that be easy to make.
Description of drawings
By below in conjunction with accompanying drawing embodiment being described, above-mentioned feature of the present utility model and technological merit will become apparent and understand easily.
Fig. 1 is the circuit diagram of the electret condenser microphone circuit of prior art; And
Fig. 2 is the circuit diagram of Electret Condencer Microphone circuit described in the utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done further detailed description.In the following embodiments, will be installed in the bluetooth earphone with Electret Condencer Microphone circuit described in the utility model is that example is described.
Fig. 2 is the circuit diagram of Electret Condencer Microphone circuit described in the utility model.As shown in Figure 2, the microphone of Electret Condencer Microphone circuit described in the utility model in the microphone circuit that comprises prior art shown in Figure 1, biasing stabilized voltage power supply, biasing resistor R1, capacitance C2 and the first decoupling capacitor C1, also comprise the second decoupling capacitor C3 and the 3rd decoupling capacitor C4.In order more clearly to describe the utility model, this omit to the description of the microphone circuit components identical of prior art.
As shown in Figure 2, the output of the bias supply of microphone circuit connects the first decoupling capacitor C1 and the second decoupling capacitor C2.Wherein, the first decoupling capacitor C1 is a microfarad range, can not play the effect that suppresses the radio frequency interference noise.Therefore, the improvements of Electret Condencer Microphone circuit of the present utility model are, increase by the second decoupling capacitor C3 between the output of biasing stabilized voltage power supply and ground, so that the radio frequency interference of filtering biasing stabilized voltage power supply output coupling; And between capacitance C2 output that is used to isolate the flip-flop that the microphone output voltage contained and ground, increase by one the 3rd decoupling capacitor C4, so that suppress the radio frequency interference that microphone picks up.
Two decoupling capacitor C3 that increased and C4 all adopt the ceramic condenser of pico farad level, in the circuit design of reality, can select according to the impedance frequency characteristic of electric capacity.In a preferred embodiment of the present utility model, use 8.2pF and the actual needs application microphone products to the model of two decoupling capacitors and parameter decoupling capacitor C3 and C4 can be bigger inhibition 2.4GHz radio frequency interference.
Electret Condencer Microphone circuit of the present utility model has increased the filter capacitor of two pico farad levels than traditional scheme, all the radio frequency interference of 2.4GHz is suppressed from the output that supplies power to microphone of microphone, reduce about 10dB but can make makes an uproar at the bottom of 800Hz, the 1600Hz of microphone voice signal, suppress effectively partner hear " " the radio frequency interference noise, in addition, also has the advantage that circuit is simple, be easy to make.Electret Condencer Microphone circuit of the present utility model is mainly used in the bluetooth earphone.
Under above-mentioned instruction of the present utility model; those skilled in the art can carry out various improvement and distortion on the basis of the foregoing description; and these improvement and distortion; all drop in the protection range of the present utility model; those skilled in the art should be understood that; above-mentioned specific descriptions are just better explained the purpose of this utility model, and protection range of the present utility model is limited by claim and equivalent thereof.
Claims (3)
1. Electret Condencer Microphone circuit, comprise with voice signal be converted to the signal of telecommunication microphone, microphone provide the biasing stabilized voltage power supply, an end of burning voltage and biasing stabilized voltage power supply the to link to each other biasing resistor (R1) that the other end links to each other with microphone, the capacitance (C2) that is connected with the output of microphone is provided, one end connects the output of biasing stabilized voltage power supply and first decoupling capacitor (C1) of other end ground connection, it is characterized in that described microphone circuit also comprises:
Second decoupling capacitor (C3), an end of described second decoupling capacitor (C3) is connected to the output of described biasing stabilized voltage power supply, the other end ground connection of described second decoupling capacitor (C3);
The 3rd decoupling capacitor (C4), an end of the 3rd decoupling capacitor (C4) is connected to the output of described capacitance (C2), the other end ground connection of described the 3rd decoupling capacitor (C4).
2. according to the described Electret Condencer Microphone circuit of claim 1, it is characterized in that described second decoupling capacitor (C3) and described the 3rd decoupling capacitor (C4) all adopt the ceramic condenser of pico farad level.
3. according to the described Electret Condencer Microphone circuit of claim 3, it is characterized in that the electric capacity of described second decoupling capacitor (C3) and described the 3rd decoupling capacitor (C4) is 8.2 pico farads.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020531396XU CN201813527U (en) | 2010-09-16 | 2010-09-16 | Capacitive microphone circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020531396XU CN201813527U (en) | 2010-09-16 | 2010-09-16 | Capacitive microphone circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201813527U true CN201813527U (en) | 2011-04-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201020531396XU Expired - Lifetime CN201813527U (en) | 2010-09-16 | 2010-09-16 | Capacitive microphone circuit |
Country Status (1)
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| CN (1) | CN201813527U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102333267A (en) * | 2011-06-29 | 2012-01-25 | 惠州Tcl移动通信有限公司 | Mobile phone and microphone circuit thereof |
| CN102917294A (en) * | 2011-08-01 | 2013-02-06 | 奥林巴斯映像株式会社 | Audio recording and playback device, and power feed method for audio recording and playback device |
| CN104469615A (en) * | 2014-12-15 | 2015-03-25 | 上海华勤通讯技术有限公司 | Terminal device and earphone circuit thereof |
| CN109155887A (en) * | 2016-05-24 | 2019-01-04 | 伯斯有限公司 | Reduce the radio frequency susceptible degree in earphone |
| CN110290447A (en) * | 2019-07-05 | 2019-09-27 | 深圳市中科蓝讯科技有限公司 | Direct current biasing unit, microphone works circuit and microphone control chip |
-
2010
- 2010-09-16 CN CN201020531396XU patent/CN201813527U/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102333267A (en) * | 2011-06-29 | 2012-01-25 | 惠州Tcl移动通信有限公司 | Mobile phone and microphone circuit thereof |
| CN102917294A (en) * | 2011-08-01 | 2013-02-06 | 奥林巴斯映像株式会社 | Audio recording and playback device, and power feed method for audio recording and playback device |
| CN102917294B (en) * | 2011-08-01 | 2016-01-13 | 奥林巴斯株式会社 | The method of supplying power to of sound recording reproducing device and sound recording reproducing device |
| CN104469615A (en) * | 2014-12-15 | 2015-03-25 | 上海华勤通讯技术有限公司 | Terminal device and earphone circuit thereof |
| CN109155887A (en) * | 2016-05-24 | 2019-01-04 | 伯斯有限公司 | Reduce the radio frequency susceptible degree in earphone |
| CN109155887B (en) * | 2016-05-24 | 2021-10-22 | 伯斯有限公司 | Earphone and circuit between microphone and audio processor of earphone |
| CN110290447A (en) * | 2019-07-05 | 2019-09-27 | 深圳市中科蓝讯科技有限公司 | Direct current biasing unit, microphone works circuit and microphone control chip |
| CN110290447B (en) * | 2019-07-05 | 2020-08-25 | 深圳市中科蓝讯科技股份有限公司 | Direct current bias unit, microphone working circuit and microphone control chip |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Weifang Goertek Electronics Co., Ltd. Assignor: Goertek Inc. Contract record no.: 2013370000052 Denomination of utility model: Capacitive microphone circuit Granted publication date: 20110427 License type: Exclusive License Record date: 20130322 |
|
| LICC | Enforcement, change and cancellation of record of contracts on the licence for exploitation of a patent or utility model | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 261031 Dongfang Road, Weifang high tech Industrial Development Zone, Shandong, China, No. 268 Patentee after: Goertek Inc. Address before: 261031 Dongfang Road, Weifang high tech Industrial Development Zone, Shandong, China, No. 268 Patentee before: Goertek Inc. |
|
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110427 |