CN203661276U - A mute control circuit - Google Patents
A mute control circuit Download PDFInfo
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- CN203661276U CN203661276U CN201320860887.2U CN201320860887U CN203661276U CN 203661276 U CN203661276 U CN 203661276U CN 201320860887 U CN201320860887 U CN 201320860887U CN 203661276 U CN203661276 U CN 203661276U
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- 239000003990 capacitor Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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- 238000012938 design process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
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Abstract
The utility model discloses a mute control circuit comprising a power amplifier chip AMP IC, a first resistor RA3, a second resistor RA18, a third resistor RA7, a fourth resistor RA8, a fifth resistor RA9, a sixth resistor RA10, a seventh resistor RA11, a first triode QA2, a second triode QA3, a capacitor EA5 and an AMP-STB interface. Pins of the power amplifier chip AMP IC include a MUTE pin, a power supply pin and a GND pin. One end of the first resistor RA3 is connected with a power supply of 12V. The other end of the first resistor RA3 is connected with the MUTE pin. One end of the third resistor RA7 is connected to a base electrode of the first triode QA2. The other end of the third resistor RA7 is connected to the AMP-STB interface. Through the adoption of the mute control circuit of the utility model, a power amplifier portion of an electronic product can be controlled to be in a mute state in electrified and power failure states.
Description
Technical field
The utility model relates to electronic technology field, relates in particular to a kind of muting control circuit.
Background technology
In the design process of consumer electronics product (as television set, Set Top Box etc.), mute circuit is an important part.The effect of described mute circuit is, when described electronic product is during because of just start or shutdown, its power amplifier part is due to the sudden change (as voltage is risen to 5V or dropped to 0V by 5V by 0V) of input signal, can produce sudden change to the output signal of power amplifier, the sudden change of this output signal will produce the abnormal sound in loudspeaker, thereby forms noise.In addition, this abnormal sound is larger on the impact of electronic product, not only can impact the quality of electronic product, even can damage described electronic product when serious, as excessive electric current may damage loudspeaker or as described in the miscellaneous part of electronic product.
At present, the mute circuit form of use has multiple.As shown in Figure 1, be a kind of mute circuit, the quiet principle of this circuit is as follows:
In the time of 12V power supply power-fail, electric capacity EA5 electric discharge, makes triode QA2 conducting, drags down MUTE pin, thus make power amplifier chips AMP IC in power down process in mute state; In the time of 12V power supply electrifying, the base voltage of triode QA2 is pulled to 3V3_STB power supply by resistance R A17, makes the conducting of QA2 triode, drags down MUTE pin, thus make power amplifier chips AMP IC in power up in mute state.
But in said method, in the time of 12V power supply electrifying, 3V3_STB power supply can not be power-up to the magnitude of voltage that makes triode QA2 conducting at once, now, chip is not in mute state, and power amplifier may make a noise and allow loudspeaker send the sound.
Summary of the invention
Technical problem to be solved in the utility model is, a kind of muting control circuit is provided, the power amplifier part that can control electronic product powering on, when power down in mute state.
For solving above technical problem, the utility model embodiment provides a kind of muting control circuit, comprises power amplifier chips AMP IC, the first resistance R A3, the second resistance R A18, the 3rd resistance R A7, the 4th resistance R A8, the 5th resistance R A9, the 6th resistance R A10, the 7th resistance R A11, the first triode QA2, the second triode QA3, electric capacity EA5 and AMP_STB interface; The pin of described power amplifier chips AMP IC comprises MUTE pin, power pins and GND pin;
Described first resistance R A3 one end connects 12V power supply, and the other end of described the first resistance R A3 is connected with described MUTE pin;
The collector electrode of described the first triode QA2 is connected with described MUTE pin, and the base stage of described the first triode QA2 is connected with one end of described the 4th resistance R A8, and the other end of described the 4th resistance R A8 is connected with the collector electrode of described the second triode QA3; The grounded emitter of described the first triode QA2;
One end of described the second resistance R A18 connects 12V power supply, and the other end of described the second resistance R A18 is connected with the base stage of described the first triode QA2; One end of described the 3rd resistance R A7 is connected with the base stage of described the first triode QA2, and the other end of described the 3rd resistance R A7 is connected with described AMP_STB interface;
The emitter of described the second triode QA3 is connected with described the 5th resistance R A9, and the other end of described the 5th resistance R A9 connects 12V power supply; The base stage of described the second triode QA3 is connected with one end of described the 7th resistance R A11, and the other end of described the 7th resistance R A11 connects 12V power supply;
The positive pole of described electric capacity EA5 is connected with the emitter of described the second triode QA3, the minus earth of described electric capacity EA5; One end of described the 6th resistance R A10 is connected with the emitter of described the second triode QA3, the other end ground connection of described the 6th resistance R A10;
Described power pins connects 12V power supply, described GND pin ground connection.
The muting control circuit that the utility model embodiment provides, by the base voltage of the first triode QA2 is pulled to 12V, the power amplifier part that makes electronic product can, with the fastest speed in mute state, be avoided power amplifier to make a noise and be caused loudspeaker to send the sound powering on, in power down process.
Brief description of the drawings
Fig. 1 is the structural representation of muting control circuit of the prior art;
Fig. 2 is the structural representation of an embodiment of the muting control circuit that provides of the utility model.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described.
Referring to Fig. 2, it is the structural representation of an embodiment of the muting control circuit that provides of the utility model.
The present embodiment provides a kind of muting control circuit, comprises power amplifier chips AMP IC, the first resistance R A3, the second resistance R A18, the 3rd resistance R A7, the 4th resistance R A8, the 5th resistance R A9, the 6th resistance R A10, the 7th resistance R A11, the first triode QA2, the second triode QA3, electric capacity EA5 and AMP_STB interface; The pin of power amplifier chips AMP IC comprises MUTE pin, power pins and GND pin;
First resistance R A3 one end connects 12V power supply, and the other end of the first resistance R A3 is connected with MUTE pin;
The collector electrode of the first triode QA2 is connected with MUTE pin, and the base stage of the first triode QA2 is connected with one end of the 4th resistance R A8, and the other end of the 4th resistance R A8 is connected with the collector electrode of the second triode QA3; The grounded emitter of the first triode QA2;
One end of the second resistance R A18 connects 12V power supply, and the other end of the second resistance R A18 is connected with the base stage of the first triode QA2; One end of the 3rd resistance R A7 is connected with the base stage of the first triode QA2, and the other end of the 3rd resistance R A7 is connected with AMP_STB interface;
The emitter of the second triode QA3 is connected with the 5th resistance R A9, and the other end of the 5th resistance R A9 connects 12V power supply; The base stage of the second triode QA3 is connected with one end of the 7th resistance R A11, and the other end of the 7th resistance R A11 connects 12V power supply;
The positive pole of electric capacity EA5 is connected with the emitter of the second triode QA3, the minus earth of electric capacity EA5; One end of the 6th resistance R A10 is connected with the emitter of the second triode QA3, the other end ground connection of the 6th resistance R A10;
Power pins connects 12V power supply, GND pin ground connection.
The operation principle of the muting control circuit below the utility model being provided is elaborated.
In the time of 12V power supply electrifying, at 12V power supply electrifying, to being greater than after 0.7V, the base potential of the first triode QA2 is high level, makes the first triode QA2 conducting, and MUTE pin is dragged down, thereby makes power amplifier chips AMP IC in mute state.In the time that 12V power supply continues to be power-up to system works voltage, AMP_STB interface is controlled, AMP_STB interface input high level, and the first triode QA2 conducting, MUTE pin is dragged down, and power amplifier chips AMP IC is in mute state.In the time that 12V power supply electrifying completes, AMP_STB interface input low level, MUTE pin is removed.Therefore, power amplifier chips AMP IC in power up completely in mute state.
In the time of 12V power supply power-fail, electric capacity EA5 starts electric discharge, after the base voltage of the second triode QA3 is lower than emitting stage voltage 0.7V, the second triode QA3 conducting, thereby the base potential of the first triode QA2 is high level, the first triode QA2 conducting, MUTE pin is dragged down, thereby makes power amplifier chips AMPIC in mute state.
Compared with prior art, the utility model embodiment is pulled to 12V the base voltage of the first triode QA2 by 3V3_STB, 12V voltage prior to 3V3_STB voltage power on, power down, and 12V voltage powers on, power down fastest, thereby the power amplifier part that makes electronic product powering on, in power down process with prestissimo in mute state, avoid power amplifier to make a noise and cause loudspeaker to send the sound.
The above is preferred implementation of the present utility model; it should be pointed out that for those skilled in the art, do not departing under the prerequisite of the utility model principle; can also make some improvements and modifications, these improvements and modifications are also considered as protection range of the present utility model.
Claims (1)
1. a muting control circuit, it is characterized in that, comprise power amplifier chips AMP IC, the first resistance R A3, the second resistance R A18, the 3rd resistance R A7, the 4th resistance R A8, the 5th resistance R A9, the 6th resistance R A10, the 7th resistance R A11, the first triode QA2, the second triode QA3, electric capacity EA5 and AMP_STB interface; The pin of described power amplifier chips AMP IC comprises MUTE pin, power pins and GND pin;
Described first resistance R A3 one end connects 12V power supply, and the other end of described the first resistance R A3 is connected with described MUTE pin;
The collector electrode of described the first triode QA2 is connected with described MUTE pin, and the base stage of described the first triode QA2 is connected with one end of described the 4th resistance R A8, and the other end of described the 4th resistance R A8 is connected with the collector electrode of described the second triode QA3; The grounded emitter of described the first triode QA2;
One end of described the second resistance R A18 connects 12V power supply, and the other end of described the second resistance R A18 is connected with the base stage of described the first triode QA2; One end of described the 3rd resistance R A7 is connected with the base stage of described the first triode QA2, and the other end of described the 3rd resistance R A7 is connected with described AMP_STB interface;
The emitter of described the second triode QA3 is connected with described the 5th resistance R A9, and the other end of described the 5th resistance R A9 connects 12V power supply; The base stage of described the second triode QA3 is connected with one end of described the 7th resistance R A11, and the other end of described the 7th resistance R A11 connects 12V power supply;
The positive pole of described electric capacity EA5 is connected with the emitter of described the second triode QA3, the minus earth of described electric capacity EA5; One end of described the 6th resistance R A10 is connected with the emitter of described the second triode QA3, the other end ground connection of described the 6th resistance R A10;
Described power pins connects 12V power supply, described GND pin ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320860887.2U CN203661276U (en) | 2013-12-24 | 2013-12-24 | A mute control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320860887.2U CN203661276U (en) | 2013-12-24 | 2013-12-24 | A mute control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203661276U true CN203661276U (en) | 2014-06-18 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320860887.2U Expired - Lifetime CN203661276U (en) | 2013-12-24 | 2013-12-24 | A mute control circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203661276U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110856079A (en) * | 2019-11-15 | 2020-02-28 | Tcl华星光电技术有限公司 | Audio system and method for eliminating noise at power-on moment |
| CN112954546A (en) * | 2021-02-01 | 2021-06-11 | 广州朗国电子科技有限公司 | Control circuit, module and terminal equipment for removing plosive by electrifying and powering off |
-
2013
- 2013-12-24 CN CN201320860887.2U patent/CN203661276U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110856079A (en) * | 2019-11-15 | 2020-02-28 | Tcl华星光电技术有限公司 | Audio system and method for eliminating noise at power-on moment |
| CN112954546A (en) * | 2021-02-01 | 2021-06-11 | 广州朗国电子科技有限公司 | Control circuit, module and terminal equipment for removing plosive by electrifying and powering off |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140618 |