CN201118787Y - Silence circuit - Google Patents
Silence circuit Download PDFInfo
- Publication number
- CN201118787Y CN201118787Y CNU2007201576663U CN200720157666U CN201118787Y CN 201118787 Y CN201118787 Y CN 201118787Y CN U2007201576663 U CNU2007201576663 U CN U2007201576663U CN 200720157666 U CN200720157666 U CN 200720157666U CN 201118787 Y CN201118787 Y CN 201118787Y
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- Prior art keywords
- mute circuit
- circuit
- mute
- power amplifier
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Abstract
The utility model discloses a silencing circuit comprising a power amplifying circuit as well as a software silencing circuit, an earphone silencing circuit, a start-up silencing circuit and a shutdown silencing circuit which are connected on silencing feet of the power amplifying circuit in parallel; wherein, the software silencing circuit receives a silencing instruction sent by a CPU and then generates a corresponding high/low level silencing signal which is output to the silencing feet of the power amplifying circuit; and the earphone silencing circuit detects the inserting state of earphones and then generates a corresponding high/low level silencing signal which is output to the silencing feet of the power amplifying circuit. The silencing circuit of the utility model has advantages of simple structure and high stability, and can respond to the silencing instruction of users and effectively solve the problem that an audio outlet device produces noise easily when in start-up and shutdown and when inserting the earphones, thereby helping to boost the audiovisual effects of television products and providing consumers with ideal audiovisual treatment.
Description
Technical field
The utility model belongs to the audio output apparatus technical field, specifically, relates to a kind of mute circuit design that is applied in the audio output apparatus.
Background technology
For present tv product, the design of mute circuit more and more receives vast television set developer's concern, and particularly for high-grade tv product, the appearance of noise can influence the complete machine quality of tv product undoubtedly.Liquid crystal TV set when bringing high-quality visual enjoyment to people, also is badly in need of high-quality audio frequency effect as one of high-grade tv product that gets consumer reception most at present.But the noise that television set is produced in switching on and shutting down or plug earphone is a very headachy problem.Mostly structure is complicated for present mute circuit, and quiet effect is not ideal enough, has had a strong impact on the complete machine performance quality of high-end TV product.
The utility model content
The utility model is in order to solve existing mute circuit complex structure, the unfavorable problem of quiet effect, a kind of novel mute circuit is provided, realized that with simple circuit configuration the software of audio output apparatus is quiet, switching on and shutting down are quiet and earphone inserts mute function, effectively avoided the appearance of noise.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of mute circuit comprises power amplifier and parallel software mute circuit, earphone mute circuit, turn-on muting circuit and the shutdown mute circuit that is connected on the quiet pin of described power amplifier; Wherein, described software mute circuit receives the quiet instruction that CPU sends, and then generates the quiet pin that corresponding high/low level mute signal exports described power amplifier to; Described earphone mute circuit detects the earphone inserting state, and then generates the quiet pin that corresponding high/low level mute signal exports described power amplifier to.
Further, the concrete structure of described turn-on muting circuit, shutdown mute circuit, earphone mute circuit and software mute circuit can adopt following form to realize:
Include a positive-negative-positive triode and a storage capacitor in described turn-on muting circuit, the base stage of described positive-negative-positive triode is by described storage capacitor ground connection, and emitter connects DC power supply, and collector electrode connects the quiet pin of described power amplifier.In system boot moment conducting in time, the speed that powers in the preferably employing system of described DC power supply DC power supply faster realizes in order to ensure described positive-negative-positive triode.
In described shutdown mute circuit, include a positive-negative-positive triode, DC power supply, potential-divider network and a storage capacitor, described DC power supply connects the base stage of positive-negative-positive triode on the one hand by potential-divider network, the positive pole that connects described storage capacitor on the other hand, the emitter of described positive-negative-positive triode connects the positive pole of described storage capacitor, and collector electrode connects the quiet pin of described power amplifier.In system closedown moment conducting in time, the fastest DC power supply of power down realizes in the preferably employing system of described DC power supply in order to ensure described positive-negative-positive triode.
In described earphone mute circuit, include a NPN type triode, its base stage connects earphone socket on the one hand, receive the detection signal of earphone inserting state, connect DC power supply by resistance on the other hand, its grounded emitter, collector electrode connects described DC power supply by another resistance on the one hand, connects the quiet pin of described power amplifier on the other hand.
In described software mute circuit, the quiet instruction output end of CPU connects the quiet pin of described power amplifier on the one hand, connect a direct current power supply by pull-up resistor on the other hand, CPU is by changing the high low-potential state of its quiet instruction output end, to realize exporting high/low level mute signal to the quiet pin of described power amplifier.
Further again, in order to prevent the phase mutual interference of signal between each mute circuit, described software mute circuit, earphone mute circuit, turn-on muting circuit and the output of shutdown mute circuit are connected the quiet pin of described power amplifier separately by a way switch diode, to realize the mutual isolation between four road mute signals.
Further again, the quiet pin high level of described power amplifier is effective.If the power amplifier that is adopted in the system is the effective power amplifier chip of quiet pin low level, then need between the output of the quiet pin of power amplifier and described software mute circuit, earphone mute circuit, turn-on muting circuit and shutdown mute circuit, be connected negative circuit, the signal of each mute circuit output is carried out exporting to after the anti-phase processing the quiet pin of described power amplifier, to realize accurate quiet control to power amplifier.
Compared with prior art, advantage of the present utility model and good effect are: mute circuit of the present utility model is simple in structure, stability is high, not only can respond user's quiet instruction, and efficiently solve audio output apparatus is easy to generate noise when switching on and shutting down and earphone insert problem, thereby help to promote the audio visual effect of tv product, give the consumer with desirable seeing and hearing enjoyment.
After reading the detailed description of the utility model execution mode in conjunction with the accompanying drawings, other characteristics of the present utility model and advantage will become clearer.
Description of drawings
Fig. 1 is the physical circuit schematic diagram of a kind of embodiment of the mute circuit that proposes of the utility model.
Embodiment
Below in conjunction with accompanying drawing embodiment of the present utility model is described in detail.
The utility model is by parallel software mute circuit, earphone mute circuit, turn-on muting circuit and the shutdown mute circuit of connecting on the quiet pin of power amplifier, and then system is carried out comprehensive noise elimination from many aspects, thereby effectively stopped the appearance of system exception noise, reached the purpose of design of improving the audio output apparatus auditory effect.
Embodiment one, and referring to shown in Figure 1, present embodiment has been enumerated wherein a kind of concrete syndeton of described mute circuit.Wherein, I partly is the software mute circuit, and II partly is the earphone mute circuit, and III partly is the turn-on muting circuit, and IV partly is the shutdown mute circuit, and it is that the effective power amplifier chip of high level is realized that power amplifier adopts quiet pin MUTE.
In the software mute circuit, the quiet instruction output end CPU_MUTE of system CPU connects the quiet pin MUTE of power amplifier on the one hand by resistance R 2, connect DC power supply VDD by pull-up resistor R1 on the other hand, described DC power supply VDD in can the employing system+the 5V DC power supply realizes, certainly, can select the DC power supply of other current potentials for use, present embodiment does not specifically limit this yet.
When system's operate as normal, the quiet instruction output end CPU_MUTE output low level signal of CPU, and then the quiet pin MUTE of power amplifier is set to electronegative potential, and the power amplifier operate as normal will receive audio signal and carry out power amplification and handle the back by its left and right acoustic channels audio signal output end.When the user sends quiet instruction or execution when changing the platform operation by remote controller or keypad, CPU calls corresponding software programs according to the command signal that receives, and then control its quiet instruction output end CPU_MUTE and export high level signal, the control power amplifier enters silent mode, block the output of its left and right acoustic channels audio signal output end, to realize that remote control is quiet and to change the platform mute function.
In the earphone mute circuit, the base stage of NPN type triode Q2 connects earphone socket by resistance R 8, receive the detection signal HPDET# of earphone inserting state, and by resistance R 7 connection DC power supply VCC, its grounded emitter, collector electrode connects DC power supply VCC by resistance R 6 on the one hand, connects the quiet pin MUTE of described power amplifier on the other hand.
When earphone did not insert, the HPDET# signal was a high level, and control triode Q2 conducting drags down its collector potential, and then to make the current potential of the quiet pin MUTE of power amplifier be low, the power amplifier operate as normal.When earphone inserted, the HPDET# signal was dragged down, thereby triode Q2 is ended; At this moment, DC power supply VCC controls it and enters silent mode by the quiet pin MUTE output high level mute signal of resistance R 6 to power amplifier, and sound is exported by earphone.
In the turn-on muting circuit, the base stage of positive-negative-positive triode Q3 is by the resistance R 11 and the storage capacitor C2 ground connection of series connection with it, and emitter connects DC power supply VCC by resistance R 10, and collector electrode connects the quiet pin MUTE of described power amplifier.Can be in time quiet in order to ensure system in start moment, described DC power supply VCC should select for use and power on DC power supply in the system fastest and realize, such as in the television system+the 12V DC power supply.
When television startup, DC power supply VCC is applied to the emitter of positive-negative-positive triode Q3 by resistance R 10, at this moment, triode Q3 is because its emitter voltage is higher than base voltage and conducting, and then by the quiet pin MUTE output high level mute signal of its collector electrode to power amplifier, quiet to realize system boot.In the process of triode Q3 conducting, along with the charging of its base current to capacitor C 2, the voltage on the capacitor C 2 constantly raises, and the difference that finally reaches emitter voltage and base voltage is less than its conduction voltage drop, thereby triode Q3 is ended.At this moment, machine system enters normal operating conditions from open state, and the turn-on muting circuit is to the quiet pin MUTE output low level signal of power amplifier, and control power amplifier operate as normal is exported sound accompaniment.
In the shutdown mute circuit, DC power supply VCC connects the base stage of positive-negative-positive triode Q1 on the one hand by the potential-divider network of being made up of resistance R 3, R4, connects the positive pole of storage capacitor C1 on the other hand, the minus earth of described storage capacitor C1.The emitter one tunnel of triode Q1 connects the positive pole of described storage capacitor C1, and another road is by resistance R 5 ground connection, and its collector electrode connects the quiet pin MUTE of described power amplifier.Can be in time quiet in order to ensure system in shutdown moment, described DC power supply VCC should select for use the fastest DC power supply of power down in the system to realize, such as in the television system+12V or+the 16V DC power supply.
When system's operate as normal, because DC power supply VCC charges to storage capacitor C1 by resistance R 3, make the emitter voltage of triode Q1 equal its base voltage and be in cut-off state, at this moment, the quiet pin MUTE of power amplifier is a low level, the power amplifier operate as normal.
When system closedown, the very fast power down of DC power supply VCC, because the voltage at capacitor C 1 two ends can not suddenly change, thereby make emitter voltage conducting of triode Q1 greater than its base voltage, the electric charge that stores in the capacitor C 1 is by triode Q1 bleed off, thereby, make power amplifier enter silent mode, the noise that produces during with the elimination system closedown by the quiet pin MUTE output high level mute signal of its collector electrode to power amplifier.
For the mute signal of above-mentioned four part mute circuits output is effectively isolated, disturb in case produce between the stop signal, present embodiment is connected a way switch diode D1～D4 respectively between the quiet pin MUTE of the output of four part mute circuits and power amplifier, described switching diode D1～D4 is conducting when this road mute circuit output high level mute signal only, thereby can realize the accurate control to power amplifier.
Certainly, described power amplifier also can adopt the effective power amplifier chip of quiet pin low level to realize, but in order to guarantee of the accurate control of above-mentioned mute circuit to power amplifier, need between the quiet pin MUTE of the negative electrode of switching diode D1～D4 and power amplifier, be connected negative circuit, mute signal current potential to mute circuit output carries out reverse process, to satisfy the normal quiet control to this power amplifier.
In addition, above-mentioned positive-negative-positive triode Q1, Q3 also can adopt the P channel MOS tube to realize, NPN type triode Q2 also can adopt other switch elements with on-off action such as N-channel MOS pipe to realize that present embodiment is not limited thereto.
Adopt above-mentioned simple and practical mute circuit, can allow tv product on performance and function, have competitiveness more, also allow the consumer can better experience the enjoyment that multimedia is lived simultaneously, for the user brings more perfectly seeing and hearing enjoyment.
Certainly, above-mentioned mute circuit also can be widely used in except that television set other to have in the electric equipment of audio output function, such as power amplifier, radio-cassette player etc., to reach the ideal effect of thorough noise elimination.
Should be noted that; the above only is a kind of preferred implementation of the present utility model; for those skilled in the art; under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.
Claims (10)
1, a kind of mute circuit comprises power amplifier, it is characterized in that: parallel software mute circuit, earphone mute circuit, turn-on muting circuit and the shutdown mute circuit of being connected with on the quiet pin of described power amplifier; Wherein, described software mute circuit receives the quiet instruction that CPU sends, and then generates the quiet pin that corresponding high/low level mute signal exports described power amplifier to; Described earphone mute circuit detects the earphone inserting state, and then generates the quiet pin that corresponding high/low level mute signal exports described power amplifier to.
2, mute circuit according to claim 1, it is characterized in that: in described turn-on muting circuit, include a positive-negative-positive triode and a storage capacitor, the base stage of described positive-negative-positive triode is by described storage capacitor ground connection, emitter connects DC power supply, and collector electrode connects the quiet pin of described power amplifier.
3, mute circuit according to claim 2 is characterized in that: described DC power supply is the speed of powering on DC power supply faster.
4, mute circuit according to claim 1, it is characterized in that: in described shutdown mute circuit, include a positive-negative-positive triode, DC power supply, potential-divider network and a storage capacitor, described DC power supply connects the base stage of positive-negative-positive triode on the one hand by potential-divider network, the positive pole that connects described storage capacitor on the other hand, the emitter of described positive-negative-positive triode connects the positive pole of described storage capacitor, and collector electrode connects the quiet pin of described power amplifier.
5, mute circuit according to claim 4 is characterized in that: described DC power supply is a power down speed DC power supply faster.
6, mute circuit according to claim 1, it is characterized in that: in described earphone mute circuit, include a NPN type triode, its base stage connects earphone socket on the one hand, connect DC power supply by resistance on the other hand, its grounded emitter, collector electrode connects described DC power supply by another resistance on the one hand, connects the quiet pin of described power amplifier on the other hand.
7, mute circuit according to claim 1 is characterized in that: in described software mute circuit, the quiet instruction output end of CPU connects the quiet pin of described power amplifier on the one hand, connects a direct current power supply by pull-up resistor on the other hand.
8, according to each described mute circuit in the claim 1 to 7, it is characterized in that: described software mute circuit, earphone mute circuit, turn-on muting circuit and the output of shutdown mute circuit are connected the quiet pin of described power amplifier separately by a way switch diode.
9, mute circuit according to claim 8 is characterized in that: the quiet pin high level of described power amplifier is effective.
10, mute circuit according to claim 8 is characterized in that: the quiet pin low level of described power amplifier is effective, connects described software mute circuit, earphone mute circuit, turn-on muting circuit and shutdown mute circuit by negative circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201576663U CN201118787Y (en) | 2007-11-23 | 2007-11-23 | Silence circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201576663U CN201118787Y (en) | 2007-11-23 | 2007-11-23 | Silence circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201118787Y true CN201118787Y (en) | 2008-09-17 |
Family
ID=39993388
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201576663U Expired - Fee Related CN201118787Y (en) | 2007-11-23 | 2007-11-23 | Silence circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201118787Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768558A (en) * | 2011-05-05 | 2012-11-07 | 鸿富锦精密工业（深圳）有限公司 | All-in-one computer having function of muting loudspeaker |
| CN103458342A (en) * | 2013-09-18 | 2013-12-18 | 上海贝岭股份有限公司 | Circuit eliminating shutdown POP sound of audio power amplifier |
| CN110381409A (en) * | 2019-08-13 | 2019-10-25 | 京东方科技集团股份有限公司 | A kind of control panel of display, its driving method and display |
-
2007
- 2007-11-23 CN CNU2007201576663U patent/CN201118787Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768558A (en) * | 2011-05-05 | 2012-11-07 | 鸿富锦精密工业（深圳）有限公司 | All-in-one computer having function of muting loudspeaker |
| CN103458342A (en) * | 2013-09-18 | 2013-12-18 | 上海贝岭股份有限公司 | Circuit eliminating shutdown POP sound of audio power amplifier |
| CN103458342B (en) * | 2013-09-18 | 2016-08-17 | 上海贝岭股份有限公司 | A kind of circuit eliminating shutdown POP sound of audio power amplifier |
| CN110381409A (en) * | 2019-08-13 | 2019-10-25 | 京东方科技集团股份有限公司 | A kind of control panel of display, its driving method and display |
| CN110381409B (en) * | 2019-08-13 | 2021-11-26 | 高创(苏州)电子有限公司 | Control panel of display, driving method thereof and display |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080917 Termination date: 20111123 |