CN203015094U - Audio frequency amplification circuit - Google Patents
Audio frequency amplification circuit Download PDFInfo
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- CN203015094U CN203015094U CN 201220729434 CN201220729434U CN203015094U CN 203015094 U CN203015094 U CN 203015094U CN 201220729434 CN201220729434 CN 201220729434 CN 201220729434 U CN201220729434 U CN 201220729434U CN 203015094 U CN203015094 U CN 203015094U
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Abstract
The utility model relates to the field of electronics and provides an audio frequency amplification circuit which is simple in structure, low in power dissipation, good in stability, high in fidelity, good in sound play effect and accurate in sound wave and is applied to a GPS system. The audio frequency amplification circuit comprises a high frequency filter circuit, an audio frequency demodulation circuit, an audio frequency power amplifier, a singlechip, a filter circuit and an audio frequency output interface, wherein the high frequency filter circuit is connect with positive and negative audio frequency outputs of an SIM300C, the audio frequency power amplifier is an LM4890, outputs of the high frequency filter circuit are connected with input ends of a third pin and a fourth pin of the LM4890 through the audio frequency demodulation circuit, an enable control end of a first pin of the LM4890 is connected with and controlled by the singlechip, a feedback resistor R1 is serially connected between the fourth pin and a fifth pin of the LM4890, and output ends of the fifth pin and an eighth pin of the LM4890 are filtered by the filter circuit and then connected with the a loudspeaker through the audio frequency output interface.
Description
Technical field
The utility model relates to electronic applications, particularly a kind of audio amplifier circuit.
Background technology
Audio amplifier circuit is to realize function of voice communication part circuit in gps system, when the user makes a phone call to the GPS terminal, after phone rings 3 times, GPS terminal automatic call answering, at this moment, the user side word, from loudspeaker, sound is released to audio amplifier circuit by the SIM300C module output audio signal on the GPS terminal, reach the effect of loud speaker, but the power consumption of existing audio amplifier circuit is large, often exist noise in sound, poor stability has affected the result of use of gps system to signal meeting moulding partial distortion.
Summary of the invention
Therefore, for above-mentioned problem, the utility model proposes a kind of simple in structure, low in energy consumption, good stability, fidelity is high, the sound result of broadcast is good, sound wave is accurate is applied to audio amplifier circuit in gps system.
for solving this technical problem, the utility model is taked following scheme: a kind of audio amplifier circuit, comprise with the SIM300C module just, the high-frequency filter circuit that negative audio frequency output is connected, the audio frequency demodulator circuit, audio-frequency power amplifier, single-chip microcomputer, filter circuit and audio output interface, described audio-frequency power amplifier is LM4890, described high-frequency filter circuit output is through audio frequency demodulator circuit and LM4890 the 3rd, the 4th pin input is connected, the control end that enables of described LM4890 the 1st pin connects and is controlled by single-chip microcomputer, also be connected in series a feedback resistance R1 between the 4th pin of described LM4890 and the 5th pin, described LM4890 the 5th, the 8th pin output is connected with loudspeaker by audio output interface after filter circuit filtering.
Further, also comprise Transient Suppression Diode, described transient voltage suppressor paralleling is connected in audio output the 5th, the 8th pin of LM4890.
By adopting the aforementioned techniques scheme; the beneficial effects of the utility model are: by adopting LM4890 as the audio-frequency power amplifier of voice communication in gps system; make the advantages such as this novel audio amplifier circuit has simple in structure, low in energy consumption, good stability, fidelity is high, the sound result of broadcast is good, sound wave is accurate; by Transient Suppression Diode further is set, make that LM4890's be subject to effective electrostatic discharge protection.
Description of drawings
Fig. 1 is the circuit diagram of the utility model embodiment.
Embodiment
Now with embodiment, the utility model is further illustrated by reference to the accompanying drawings.
with reference to figure 1, preferred a kind of audio amplifier circuit of the present utility model, comprise with SIM300C module 1 just, negative audio frequency output SPK1P, the high-frequency filter circuit 2 that SPK1N is connected, audio frequency demodulator circuit 3, audio-frequency power amplifier 4, single-chip microcomputer 5, filter circuit 6, audio output interface 7 and Transient Suppression Diode EL61, described audio-frequency power amplifier 4 is LM4890, described high-frequency filter circuit 2 outputs are through audio frequency demodulator circuit 3 and LM4890 the 3rd, the 4th pin input is connected, described LM4890 the 1st pin enable the MCU_GPRS_AUDIO pin that control end connects and be controlled by single-chip microcomputer 5, also be connected in series a feedback resistance R1 between the 4th pin of described LM4890 and the 5th pin, described LM4890 the 5th, the 8th pin output is connected with loudspeaker by audio output interface 7 after filter circuit 6 filtering, described LM4890 the 6th pin meets power vd D through a filter capacitor C11, described LM4890 the 7th pin ground connection, described Transient Suppression Diode EL61(is called for short TVS) be connected in parallel in the audio output the 5th of LM4890, the 8th pin, described high-frequency filter circuit 2 is by filter capacitor C1, C2, C3, C4 consists of, and this high-frequency filter circuit 2 filters the high frequency of 900MHz and 1800MHz, and described filter circuit 6 comprises high-frequency filter capacitor C12, C13, C14, C15.
The utility model is by adopting LM4890 as the audio-frequency power amplifier of voice communication in gps system; make the advantages such as this novel audio amplifier circuit has simple in structure, low in energy consumption, good stability, fidelity is high, the sound result of broadcast is good, sound wave is accurate; by Transient Suppression Diode further is set, make that LM4890's be subject to effective electrostatic discharge protection.
Although specifically show and introduced the utility model in conjunction with preferred embodiment; but the those skilled in the art should be understood that; within not breaking away from the spirit and scope of the present utility model that appended claims limits; can make a variety of changes the utility model in the form and details, be protection range of the present utility model.
Claims (2)
1. audio amplifier circuit, comprise with the SIM300C module just, the high-frequency filter circuit that negative audio frequency output is connected, the audio frequency demodulator circuit, audio-frequency power amplifier, single-chip microcomputer, filter circuit and audio output interface, it is characterized in that: described audio-frequency power amplifier is LM4890, described high-frequency filter circuit output is through audio frequency demodulator circuit and LM4890 the 3rd, the 4th pin input is connected, the control end that enables of described LM4890 the 1st pin connects and is controlled by single-chip microcomputer, also be connected in series a feedback resistance R1 between the 4th pin of described LM4890 and the 5th pin, described LM4890 the 5th, the 8th pin output is connected with loudspeaker by audio output interface after filter circuit filtering.
2. audio amplifier circuit according to claim 1, it is characterized in that: also comprise Transient Suppression Diode, described transient voltage suppressor paralleling is connected in audio output the 5th, the 8th pin of LM4890.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220729434 CN203015094U (en) | 2012-12-26 | 2012-12-26 | Audio frequency amplification circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220729434 CN203015094U (en) | 2012-12-26 | 2012-12-26 | Audio frequency amplification circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203015094U true CN203015094U (en) | 2013-06-19 |
Family
ID=48606647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220729434 Expired - Fee Related CN203015094U (en) | 2012-12-26 | 2012-12-26 | Audio frequency amplification circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203015094U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110719547A (en) * | 2018-07-13 | 2020-01-21 | 鸿富锦精密工业(武汉)有限公司 | Audio circuit assembly |
-
2012
- 2012-12-26 CN CN 201220729434 patent/CN203015094U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110719547A (en) * | 2018-07-13 | 2020-01-21 | 鸿富锦精密工业(武汉)有限公司 | Audio circuit assembly |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130619 Termination date: 20151226 |
|
| EXPY | Termination of patent right or utility model |