CN201263215Y - Capacitor type microphone and circuit board assembly thereof - Google Patents
Capacitor type microphone and circuit board assembly thereof Download PDFInfo
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- CN201263215Y CN201263215Y CNU2008200946494U CN200820094649U CN201263215Y CN 201263215 Y CN201263215 Y CN 201263215Y CN U2008200946494 U CNU2008200946494 U CN U2008200946494U CN 200820094649 U CN200820094649 U CN 200820094649U CN 201263215 Y CN201263215 Y CN 201263215Y
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- effect transistor
- junction field
- circuit board
- electric capacity
- condenser microphone
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Abstract
The utility model discloses a condenser microphone and a circuit board component thereof. The condenser microphone comprises an acoustic-electric conversion component and the circuit board component. The circuit board component comprises a junction field-effect transistor, a transient suppression diode, an earth terminal and an output end; one end of the acoustic-electric conversion component is connected with a grid of the junction field-effect transistor and the other end thereof is connected with the earth terminal; a source electrode of the junction field-effect transistor is connected with the earth terminal; a drain electrode of the junction field-effect transistor is connected with the output end; and the transient suppression diode is connected between the drain electrode and the source electrode of the junction field-effect transistor. Owing to the selection of the transient suppression diode connected between the drain electrode and the source electrode of the junction field-effect transistor, the condenser microphone of the circuit board component of the technical scheme can provide effective protection for the junction field-effect transistor and effectively prevent over current generated by high pressure static electricity from damaging the junction field-effect transistor.
Description
Technical field
The utility model belongs to the electroacoustic techniques field, relates to condenser microphone, is specifically related to a kind of the have condenser microphone of protective circuit and the circuit board assemblies that this condenser microphone comprises.
Background technology
Along with developing rapidly of mechanics of communication, a large amount of condenser microphones are applied in the communication product.For each parts of communication product, all required accurate, reliable antistatic interference characteristic, thereby guaranteed the reliability of communication product.Concerning condenser microphone, accurately, reliable antistatic interference characteristic should refer to: when condenser microphone has produced the static discharge phenomenon of high pressure in because of external environment conditions such as air, perhaps work as condenser microphone and be connected directly to the terminal that has produced high-pressure electrostatic and produce the static discharge phenomenon, the internal circuit of condenser microphone still can not damage.Conventional condenser microphone can not satisfy such static discharge condition, so can not prevent because the damage of the junction field effect transistor that overcurrent caused that high-pressure electrostatic produces.
The technical scheme that existing condenser microphone uses has following selection: 1) connect an electric capacity between the source electrode of junction field effect transistor (JFET) and drain electrode, it can play the effect of filtering, simultaneously also can instantaneous charging and have certain anlistatig function, however this class component of ceramic capacitor is more weak to the holding capacity of high pressure.When impacting if any the transient voltage of 10kV, can cause about 60% damage to ceramic capacitor, the heat that is produced when transient voltage is attacked, ceramic capacitor also have no idea effectively it to be left, and make its as easy as rolling off a log damage, thereby generally can not adopt.2) connect a Zener diode between the source electrode of junction field effect transistor JFET and drain electrode connect, less because of the P/N junction area of Zener diode, this structure all is affected its ability of bearing high pressure and efficient.In addition, Zener diode also has the higher and slower shortcoming of radiating rate of the voltage of inhibition.3) between the source electrode of junction field effect transistor JFET and drain electrode, connect a piezo-resistance; the same existence suppressed voltage meeting problem of higher; what piezo-resistance adopted simultaneously is the Physical Absorption principle; therefore every through primary circuit protection running; material will be subjected to the certain physical infringement; the leak channel that formation can't recover constantly shortens its life-span.
In sum, existing condenser microphone all can not effectively prevent because the overcurrent that high-pressure electrostatic produced causes junction field effect transistor to damage.
Summary of the invention
The technical problems to be solved in the utility model provides a kind of circuit board assemblies of condenser microphone and comprises the condenser microphone of this circuit board assemblies, and it can effectively prevent because the overcurrent that high-pressure electrostatic produced causes the junction field effect transistor of condenser microphone to damage.
The key that addresses the above problem is to find a kind ofly can fall rapidly that high pressure, sustaining voltage are stable, the life-span is very long or without limits, the components and parts of practicality and high efficiency.In order to solve the problems of the technologies described above, the utility model adopts following technical scheme:
Condenser microphone comprises: acoustic-electric converting member and circuit board assemblies, and described circuit board assemblies comprises junction field effect transistor, Transient Suppression Diode and earth terminal and output; One end of described acoustic-electric converting member is connected with the grid of junction field effect transistor, and the other end is connected with earth terminal; The drain electrode of described junction field effect transistor is connected with described output, and source electrode is connected with earth terminal; Described Transient Suppression Diode is connected between the drain electrode and source electrode of junction field effect transistor.
In the optimized technical scheme, described circuit board assemblies also comprises first electric capacity and second electric capacity that is used for filtering characteristic frequency clutter, and described first electric capacity and second electric capacity all are connected between the drain electrode and source electrode of junction field effect transistor.
In the general technical scheme, the capacitance of described first electric capacity and second electric capacity between 33 pico farads, can certainly be selected certain capacitance for use: as 100 pico farads at 10 pico farads according to the actual needs.
In the optimized technical scheme, described Transient Suppression Diode also can be two-way Transient Suppression Diode.
Adopt the condenser microphone of technical solutions of the utility model circuit board assemblies, the beneficial effect that is compared with the prior art is:
Owing to select for use Transient Suppression Diode to be connected between the drain electrode and source electrode of junction field effect transistor; can can be good at effectively preventing because the overcurrent that high-pressure electrostatic produced causes junction field effect transistor to damage for junction field effect transistor provides effective protection.
Owing to further between the drain electrode of junction field effect transistor and source electrode, be connected first electric capacity and second electric capacity, the clutter of its filtering special frequency channel targetedly.
Since the capacitance of first electric capacity and second electric capacity at 10 pico farads between 33 pico farads, and generally using the frequency band of 1800MHZ or the frequency band of 900MHZ in the current mobile communication terminal, first electric capacity and second electric capacity is filtering 1800MHZ and near the clutter of 900MHZ effectively.
Owing to further adopt two-way Transient Suppression Diode, and two-way Transient Suppression Diode does not have direction, can better adapt to alternating current circuit.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model embodiment one condenser microphone;
Fig. 2 is another circuit theory diagrams of the utility model embodiment one condenser microphone;
Fig. 3 is another circuit theory diagrams of the utility model embodiment one condenser microphone;
Fig. 4 is the circuit theory diagrams of the utility model embodiment two condenser microphones.
Embodiment
Embodiment one
As shown in Figure 1, the condenser microphone of this embodiment comprises: the acoustic-electric converting member 1 that is used for voice signal is converted to the signal of telecommunication, and be electrically connected with described acoustic-electric converting member, the signal of telecommunication of described acoustic-electric converting member output is amplified the circuit board assemblies that waits processing.Circuit board assemblies comprises: be used for junction field effect transistor (JFET) 2 that the described signal of telecommunication is amplified, the Transient Suppression Diode that shields (TVS) 5, be used for first electric capacity 6, second electric capacity 7 of filtering clutter and output 3 and earth terminal 4.
Wherein an end of acoustic-electric converting member 1 connects earth terminal 4, and the other end connects the grid of junction field effect transistor 2.Need to prove that acoustic-electric converting member 1 herein is by vibrating diaphragm, fixed polar plate and other equivalent capacity that constitutes such as auxiliary components such as pads.When transfer voice when the vibrating diaphragm, cause vibration of diaphragm, thereby make the clearance distance between vibrating diaphragm and the fixed polar plate change that the capacitance of the equivalent capacity of being made up of vibrating diaphragm and fixed polar plate changes, thereby voice signal is converted to the signal of telecommunication.
The drain electrode of junction field effect transistor 2 connects output 3, and source electrode connects earth terminal 4.The described signal of telecommunication is applied to the grid of junction field effect transistor 2 and is amplified, and exports to subsequent conditioning circuit by output 3 then.Described Transient Suppression Diode 5 is connected between the source electrode and drain electrode of junction field effect transistor 2; it utilizes semi-conductive clamper principle; when standing instantaneous high pressure; can immediately energy be discharged by avalanche theory; device can not suffer damage during protecting other; can prevent effectively that especially the junction field effect transistor that overcurrent caused 2 that high-pressure electrostatic produces from damaging, so it makes condenser microphone integral body can bear very high electrostatic potential.And Transient Suppression Diode 5 do not have age limit basically, can more effectively guarantee the reliability of condenser microphone.
In addition, the condenser microphone of this concrete real-time mode also is being connected with first electric capacity 6 and second electric capacity 7 between the source electrode of junction field effect transistor 2 and drain electrode.First electric capacity 6 and second electric capacity 7 mainly play the filtering and eliminating noise sound, its capacitance at 10 pico farads between 33 pico farads, capacitance such as first electric capacity 6 is 10 pico farads, the capacitance of second electric capacity 7 is 33 pico farads, owing to generally use the frequency band of 1800MHZ or the frequency band of 900MHZ in the current mobile communication terminal, first electric capacity 6 and second electric capacity 7 is filtering 1800MHZ and near the clutter of 900MHZ effectively; It can certainly be the capacitance that specifically need select other for use.
Fig. 2 and the two kinds of execution modes in addition that Figure 3 shows that condenser microphone, the difference of itself and Fig. 1 is that Transient Suppression Diode 5 is positioned at first electric capacity 6 and second electric capacity 7, perhaps Transient Suppression Diode 5 is positioned at before first electric capacity 6 and second electric capacity 7, its effect is all similar, and just the simple equivalence of circuit is replaced.
Through experiment, Transient Suppression Diode 5 utilizes semi-conductive clamper principle, when standing instantaneous high pressure; immediately energy is discharged by avalanche theory; the effect that reaches protection junction field effect transistor 2 that can be very desirable, its volume is very little simultaneously, helps industrial production.
Condenser microphone of the present utility model adopts Transient Suppression Diode 5 to strengthen the tolerance performance of electrostatic potential that the outside is applied, protects junction field effect transistor 2.Compare and use the condenser microphone of ceramic capacitor as protection device, the voltage that can bear is higher, heat radiation is faster, and not fragile; Compare and use the condenser microphone of Zener diode as protection device, the voltage that can bear is higher, efficient is higher, inhibition voltage is lower and heat radiation is very fast; Compare and adopt the condenser microphone of piezo-resistance as protection device, the voltage that can bear is higher, and it is longer to have lower inhibition voltage and a life-span.
Embodiment two
The electret microphone of this embodiment is with the difference of embodiment one that as shown in Figure 4 what this place adopted is two-way Transient Suppression Diode 8.Unidirectional Transient Suppression Diode generally is applicable to DC circuit, and two-way Transient Suppression Diode 8 does not have directivity, the general use in the circuit that exchanges.
Above content be in conjunction with concrete preferred implementation to further describing that the utility model is done, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, under the prerequisite that does not break away from the utility model design, can also make some simple deduction or replace, all should be considered as belonging to protection range of the present utility model.
Claims (8)
1, condenser microphone comprises: acoustic-electric converting member and circuit board assemblies, described circuit board assemblies comprise junction field effect transistor and earth terminal and output; One end of described acoustic-electric converting member is connected with the grid of junction field effect transistor, and the other end is connected with earth terminal; The drain electrode of described junction field effect transistor is connected with described output, source electrode is connected with earth terminal, it is characterized in that described circuit board assemblies also comprises Transient Suppression Diode, described Transient Suppression Diode is connected between the drain electrode and source electrode of junction field effect transistor.
2, condenser microphone as claimed in claim 1, it is characterized in that, described circuit board assemblies also comprises first electric capacity and second electric capacity that is used for filtering characteristic frequency clutter, and described first electric capacity and second electric capacity all are connected between the drain electrode and source electrode of junction field effect transistor.
3, condenser microphone as claimed in claim 2 is characterized in that, the capacitance of described first electric capacity and second electric capacity at 10 pico farads between 33 pico farads.
4, as any described condenser microphone in the claim 1 to 3, it is characterized in that described Transient Suppression Diode is two-way Transient Suppression Diode.
5, circuit board assemblies, it is used for condenser microphone, comprises circuit board and installing junction field effect transistor and earth terminal and output thereon; The drain electrode of described junction field effect transistor is connected with described output, source electrode is connected with earth terminal, it is characterized in that the circuit board assemblies of described condenser microphone also comprises Transient Suppression Diode, described Transient Suppression Diode is connected between the drain electrode and source electrode of junction field effect transistor.
6, circuit board assemblies as claimed in claim 5, it is characterized in that, described circuit board assemblies also comprises first electric capacity and second electric capacity that is used for filtering characteristic frequency clutter, and described first electric capacity and second electric capacity all are connected between the drain electrode and source electrode of junction field effect transistor.
7, circuit board assemblies as claimed in claim 6 is characterized in that, the capacitance of described first electric capacity and second electric capacity at 10 pico farads between 33 pico farads.
8, as any described circuit board assemblies in the claim 5 to 7, it is characterized in that described Transient Suppression Diode is two-way Transient Suppression Diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200946494U CN201263215Y (en) | 2008-06-16 | 2008-06-16 | Capacitor type microphone and circuit board assembly thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200946494U CN201263215Y (en) | 2008-06-16 | 2008-06-16 | Capacitor type microphone and circuit board assembly thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201263215Y true CN201263215Y (en) | 2009-06-24 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008200946494U Expired - Fee Related CN201263215Y (en) | 2008-06-16 | 2008-06-16 | Capacitor type microphone and circuit board assembly thereof |
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| Country | Link |
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| CN (1) | CN201263215Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893477A (en) * | 2010-07-01 | 2010-11-24 | 北京航空航天大学 | Measuring microphone |
| CN102170176A (en) * | 2011-04-28 | 2011-08-31 | 华为终端有限公司 | Energy storage method and device |
| CN105633066A (en) * | 2016-03-23 | 2016-06-01 | 昆山永续智财技术服务有限公司 | High-voltage transistor structure |
-
2008
- 2008-06-16 CN CNU2008200946494U patent/CN201263215Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893477A (en) * | 2010-07-01 | 2010-11-24 | 北京航空航天大学 | Measuring microphone |
| CN101893477B (en) * | 2010-07-01 | 2012-07-04 | 北京航空航天大学 | Measuring microphone |
| CN102170176A (en) * | 2011-04-28 | 2011-08-31 | 华为终端有限公司 | Energy storage method and device |
| CN102170176B (en) * | 2011-04-28 | 2013-07-10 | 华为终端有限公司 | Energy storage method and device |
| CN105633066A (en) * | 2016-03-23 | 2016-06-01 | 昆山永续智财技术服务有限公司 | High-voltage transistor structure |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: SHENZHEN HORN ACOUSTICS CO., LTD. Free format text: FORMER NAME: SHENZHEN HORN ELECTROACOUSTIC TECHNOLOGY CO., LTD. |
|
| CP03 | Change of name, title or address |
Address after: Shenzhen, Guangdong, Baoan District, Longhua big wave with rich industrial park 17, zip code: 518109 Patentee after: Shenzhen Horn Audio Co., Ltd. Address before: Shenzhen, Guangdong, Baoan District, Longhua big wave with rich industrial park 17, zip code: 518109 Patentee before: Shenzhen Horn Electroacoustic Technology Co., Ltd. |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090624 Termination date: 20120616 |