CN217770324U - Ear discharge circuit using discrete elements - Google Patents
Ear discharge circuit using discrete elements Download PDFInfo
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- CN217770324U CN217770324U CN202221607850.4U CN202221607850U CN217770324U CN 217770324 U CN217770324 U CN 217770324U CN 202221607850 U CN202221607850 U CN 202221607850U CN 217770324 U CN217770324 U CN 217770324U
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Abstract
The utility model provides an ear discharge circuit using discrete components, which comprises a power supply control circuit, a player front end, a discrete earphone amplifying circuit and a mute control circuit, wherein a volume control circuit is connected between the discrete earphone amplifying circuit and the player front end, and the discrete earphone amplifying circuit outputs a power output signal to the earphone output end through the mute control circuit; the discrete earphone amplifying circuit is of a three-stage amplifying circuit structure and comprises a differential output input stage, a main voltage amplifying stage and a power amplifying output stage, wherein the differential output input stage is used for providing a first amplifying signal, the main voltage amplifying stage is used for providing a second amplifying signal, the power amplifying output stage is used for providing a third amplifying signal, and a voltage negative feedback circuit is connected between the differential output input stage and the power amplifying output stage. The utility model discloses can obtain required performance and timbre listening according to the nimble adjusting circuit operating condition of product demand, tone quality has had more obvious promotion.
Description
Technical Field
The utility model relates to a portable music player technical field, concretely relates to use discrete component's ear circuit of putting.
Background
At present, when HIFI audio source products such as high-fidelity CD players, music players, digital audio decoders and the like are designed, an audio output circuit is mostly built by a high-level operational amplifier IC (integrated circuit), although the conventional technical indexes can be well exerted, the cost is high, the current driving force is relatively insufficient, the subjective auditory sense harmonic overtone is less, the subjective auditory sense harmonic overtone is drier, and the 'digital taste' is stronger; the audio output circuit is built by adopting discrete elements, and the audio output circuit has the advantages of low cost, but the audio output circuit is more complicated than a high-level operational amplifier IC in the aspects of circuit architecture, element selection, parameter selection and the like, and all indexes are difficult to meet the requirements at the same time.
The existing discrete amplifying circuit is not flexible enough, and the working state of the circuit can not be flexibly adjusted according to the product requirement to obtain the required performance and the tone perception. And, instantaneous pop noise may be caused at the time of power switching and gain switching.
Therefore, the design of an earphone amplifying circuit based on discrete components enables the comprehensive sound output index of the product to reach the leading level of the industry, and is a problem which needs to be solved urgently at present.
SUMMERY OF THE UTILITY MODEL
The utility model provides a pair of use discrete component's ear is put circuit, it has mainly solved the problem that complicated problems such as circuit framework, component lectotype, parameter selection and circuit can not dispose in a flexible way, can obtain required performance and timbre listening according to the nimble adjusting circuit operating condition of product demand, and tone quality has had more obvious promotion.
The utility model discloses a following technical scheme realizes above-mentioned purpose:
an ear discharge circuit using discrete elements, comprising: the device comprises a power supply control circuit, a player front end, a discrete earphone amplifying circuit and a mute control circuit, wherein the input end of the power supply control circuit is connected with a power supply, the first output end of the power supply control circuit outputs a first controllable power supply to the discrete earphone amplifying circuit under the control of an MCU circuit, the second output end of the power supply control circuit outputs a second controllable power supply to the player front end under the control of the MCU circuit, a volume control circuit is connected between the discrete earphone amplifying circuit and the player front end, and the discrete earphone amplifying circuit outputs a power output signal to the earphone output end through the mute control circuit; the discrete earphone amplifying circuit is of a three-stage amplifying circuit structure and comprises a differential output input stage, a main voltage amplifying stage and a power amplifying output stage, wherein the differential output input stage is used for providing a first amplifying signal, the main voltage amplifying stage is used for providing a second amplifying signal, the power amplifying output stage is used for providing a third amplifying signal, the differential output input stage is connected with the main voltage amplifying stage, the main voltage amplifying stage is connected with the power amplifying output stage, and a voltage negative feedback circuit is connected between the differential output input stage and the power amplifying output stage.
The front end of the player is used for decoding a music playing signal and then outputting an analog line audio signal to the volume control circuit, and the volume control circuit outputs a preceding stage audio signal to the discrete earphone amplifying circuit for power amplification, so that a power output signal is formed.
In a further aspect, the circuitry further includes a user interface configured to display a menu system and receive input, the user interface coupled to the player front end.
In a further aspect, the power control circuit includes a DC/DC converter chip, a first resistor is connected across a pin VPOS and a pin FBP of the DC/DC converter chip, and a second resistor is connected across a pin VNEG and a pin FBN of the DC/DC converter chip.
The differential output input stage comprises a first constant current source, a first field effect tube and a second field effect tube, wherein the grid electrode of the first field effect tube is connected to the preceding stage audio signal, the source electrode of the first field effect tube is connected with the first constant current source, the grid electrode of the second field effect tube is connected to the voltage negative feedback circuit, the source electrode of the second field effect tube is connected with the first constant current source, and the drain electrodes of the first field effect tube and the second field effect tube are further connected with a first power type double triode.
The main voltage amplifying stage comprises a first triode, a bias circuit and a second constant current source, wherein the base electrode of the first triode is connected to the drain electrode of the first field effect transistor, the collector electrode of the first triode is connected with the bias circuit, and the bias circuit is connected with the second constant current source.
According to a further scheme, the power amplification output stage comprises a second triode and a third triode, the second triode and the third triode are both power type double triodes with twin structures, and the second triode and the third triode are connected in parallel to output.
The second triode is a second power type triode, the third triode is a third power type triode, the bases of the two triodes of the second power type triode are connected to the voltage negative feedback circuit, the emitting electrodes of the two triodes of the second power type triode are respectively connected to the nodes A and B, the bases of the two triodes of the third power type triode are connected to the voltage negative feedback circuit, and the emitting electrodes of the two triodes of the third power type triode are respectively connected to the nodes A and B.
According to a further scheme, the voltage negative feedback circuit comprises a first switch, a second switch, a third resistor, a fourth resistor and a fifth resistor, a first end of the first switch is connected with a second end of the third resistor, a first end of the second switch is connected with a second end of the fourth resistor, a second end of the first switch and a second end of the second switch are respectively connected with the power supply control circuit, a first end of the third resistor and a first end of the fourth resistor are connected to a grid electrode of the second field-effect tube, a first end of the fourth resistor is connected with a second end of the fifth resistor, and a first end of the fifth resistor is connected to a power output end of the power amplification output stage.
Further, the first switch and the second switch are analog switches FSA2275.
Therefore, the utility model provides an use discrete component's ear discharge circuit, its earphone amplifier circuit is tertiary amplifier circuit structure, wherein, constitute differential output by field effect transistor and first constant current source and go into the level, by the triode, bias circuit and second constant current source constitute main voltage amplifier stage, constitute power amplification (current amplification) output stage by two power type double triodes, with the improvement current output driving force, constitute ear discharge circuit's voltage negative feedback circuit by switch and resistance, be used for feeding back audio signal, make the audio frequency noise of output few, sound quality is good. Therefore, the utility model discloses can obtain required performance and tone quality listening according to the nimble adjusting circuit operating condition of product demand for tone quality has had more obvious promotion.
Further, the utility model discloses a discrete components such as field effect transistor utilize field effect transistor input impedance height, small in noise, characteristics that dynamic range is big as core component, have both improved the technical indicator of circuit, make it accord with relevant national standard and industry standard, have improved subjective sense of hearing again, make the sound evaluation index reach the requirement of HIFI class product. In addition, because the circuit design is carried out by adopting the conventional discrete components, compared with a circuit built by a high-grade operational amplifier IC, the product cost is greatly reduced.
Further, the utility model discloses use high performance analog switch to realize power output channel's silence control, the instantaneous popping that arouses when eliminating power switching and gain switching.
Furthermore, the power control, gain control, volume control, mute control and other functions are all controlled by the MCU at the front end of the player.
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Drawings
Fig. 1 is a schematic diagram of an embodiment of an ear discharge circuit using discrete components according to the present invention.
Fig. 2 is a schematic diagram of a power control circuit in an embodiment of an ear discharge circuit using discrete components according to the present invention.
Fig. 3 is a schematic circuit diagram of a discrete earphone amplifier circuit in an embodiment of an ear discharge circuit using discrete components according to the present invention.
Detailed Description
In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined below to clearly and completely describe the technical solution of the embodiments of the present invention. It is to be understood that the embodiments described are some, not all embodiments of the invention. Based on the described embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
Referring to fig. 1 to 3, the present invention relates to an ear discharge circuit using discrete components, including: the power supply control circuit 2, the player front end 3, the discrete earphone amplifying circuit 4, the mute control circuit 5, the input end of the power supply control circuit 2 is connected to the power supply 1, the first output end of the power supply control circuit 2 outputs the first controllable power supply to the discrete earphone amplifying circuit 4 under the control of the MCU circuit, the second output end of the power supply control circuit 2 outputs the second controllable power supply to the player front end 3 under the control of the MCU circuit, a volume control circuit 6 is connected between the discrete earphone amplifying circuit 4 and the player front end 3, and the discrete earphone amplifying circuit 4 outputs a power output signal to the earphone output end 7 through the mute control circuit 5.
The front end 3 of the player is used for decoding the music playing signal and then outputting an analog line audio signal to the volume control circuit 6, and the volume control circuit 6 outputs a preceding stage audio signal to the discrete earphone amplifying circuit 4 for power amplification, so that a power output signal is formed.
Specifically, the power supply 1 of this embodiment may be a lithium ion polymer battery, the lithium ion polymer battery supplies power to the power supply control circuit 2, the power supply control circuit 2 outputs a controllable power supply to the discrete earphone amplification circuit 4 under the control of the MCU, the player front end 3 is responsible for decoding music and outputting an analog line audio signal to the volume control circuit 6 (NJW 1195A), a level-controlled preceding-stage audio signal is output to the discrete earphone amplification circuit for power amplification, the power output signal drives the earphone to make a sound after transient noise switching is eliminated by the mute control circuit (FSA 2275), and the MCU receives a user instruction through the user interface UI and controls other circuits to cooperatively realize all functions of the player.
It can be seen that, in order to satisfy the portability of the product, the present embodiment uses a lithium ion polymer battery, which supports charging of the battery through a USB universal interface.
Further, the present embodiment uses a high-performance volume control chip (NJW 1195A) to control the earphone volume to obtain lower background noise and better audio index.
In this embodiment, the discrete earphone amplifying circuit 4 is a three-stage amplifying circuit structure, and includes a differential output input stage for providing a first amplified signal, a main voltage amplifying stage for providing a second amplified signal, and a power amplifying output stage for providing a third amplified signal, where the differential output input stage is connected to the main voltage amplifying stage, the main voltage amplifying stage is connected to the power amplifying output stage, and a voltage negative feedback circuit is connected between the differential output input stage and the power amplifying output stage.
In this embodiment the circuit further comprises a user interface 8 configured to display a menu system and to receive input, the user interface 8 being connected to the player front end 3. It can be seen that the user interface 8 is a display screen, and the user interface 8 of the display screen is provided with a power mode switching button, or a product is provided with a physical key, which is convenient for the user to operate.
As shown in fig. 2, the power supply control circuit 2 includes a DC/DC converter chip U1, a resistor R20, a resistor R21, and a resistor R22 are connected across between the positive voltage power supply output pin VPOS and the FBP pin of the DC/DC converter chip U1, switches are connected to the resistor R21 and the resistor R22, respectively, a resistor R23, a resistor R24, and a resistor R25 are connected across between the negative voltage power supply output pin VNEG and the FBN pin of the DC/DC converter chip U1, and switches are connected to the resistor R24 and the resistor R25, respectively. The switch of the present embodiment is an analog switch FSA2275. It can be seen that, in the embodiment, a high-efficiency high-performance DC/DC power supply chip (e.g., LT 8582) is used to provide a voltage-controllable working power supply for the ear discharge circuit, and a high-performance analog switch (FSA 2275) is used to switch a voltage setting resistor of the DC/DC circuit to obtain a required output voltage.
As shown in fig. 3, the differential input/output stage includes a constant current source I1, a field effect transistor Q1 and a field effect transistor Q2, a gate of the field effect transistor Q1 is connected to a preceding stage audio signal, a source of the field effect transistor Q1 is connected to the constant current source I1, a gate of the field effect transistor Q2 is connected to the voltage negative feedback circuit, a source of the field effect transistor Q2 is connected to the constant current source I1, and drains of the field effect transistor Q1 and the field effect transistor Q2 are further connected to a first power type double triode, such as a triode Q3-a and a triode Q3-B.
In the present embodiment, the main voltage amplifier stage includes a transistor Q5, a bias circuit 10, and a constant current source I2, a base of the transistor Q5 is connected to a drain of the field effect transistor Q1, a collector of the transistor Q5 is connected to the bias circuit 10, and the bias circuit 10 is connected to the constant current source I2.
In this embodiment, the power amplification output stage includes a second triode and a third triode, both of which are power type dual triodes with twin structure, and the second triode and the third triode are output in parallel.
Wherein the second triode is a second power type double triode, such as a triode Q7-A and a triode Q7-B, the third triode is a third power type double triode, such as a triode Q9-A and a triode Q9-B, bases of the two triodes of the second power type double triode are connected to a voltage negative feedback circuit, such as bases of the triode Q7-A and the triode Q7-B are connected between a collector of the triode Q5 and the bias circuit 10, emitters of the two triodes of the second power type double triode are respectively connected to the nodes A and B, an emitter of the triode Q7-A is connected to the node A, an emitter of the triode Q7-B is connected to the node B, such as bases of the two triodes of the third power type double triode are connected to the voltage negative feedback circuit, such as bases of the triode Q9-A and the triode Q9-B are connected between the bias circuit 10 and the constant current source I2, emitters of the two triodes of the third power type double triode are respectively connected to the nodes A and B, such as an emitter of the triode Q9-A is connected to the node A, and an emitter of the triode Q9-B is connected to the node B.
In this embodiment, the voltage negative feedback circuit includes a switch S1, a switch S2, a resistor R28, a resistor R29, and a resistor 18, a first end of the switch S1 is connected to the second end of the resistor R28, a first end of the switch S2 is connected to the second end of the resistor R29, a second end of the switch S1 and a second end of the switch S2 are respectively connected to the power control circuit 2, a first end of the resistor R28 and a first end of the resistor R29 are connected to the gate of the fet Q2, a first end of the resistor R29 is connected to the second end of the resistor 18, and a first end of the resistor 18 is connected to the power output terminal of the power amplification output stage.
From this, the utility model provides an use discrete component's ear discharge circuit, its earphone amplifier circuit is tertiary amplifier circuit structure, wherein, constitute differential output by field effect transistor and constant current source I1 and go into the level, by the triode, bias circuit 10 and constant current source I2 constitute main voltage amplifier stage, constitute power amplification (current amplification) output stage by two power type double triodes, with the improvement current output driving force, constitute ear discharge circuit's voltage negative feedback circuit by switch and resistance, be used for feeding back audio signal, make the audio frequency noise of output few, sound quality is good. Therefore, the utility model discloses can obtain required performance and timbre listening according to the nimble adjusting circuit operating condition of product demand for tone quality has had more obvious promotion.
Further, the utility model discloses a discrete components such as field effect transistor utilize field effect transistor input impedance height, small in noise, characteristics that dynamic range is big as core component, have both improved the technical indicator of circuit, make it accord with relevant national standard and industry standard, have improved subjective sense of hearing again, make the sound evaluation index reach the requirement of HIFI class product. In addition, because the circuit design is carried out by adopting the conventional discrete components, compared with a circuit built by a high-grade operational amplifier IC, the product cost is greatly reduced.
Further, the utility model discloses use high performance analog switch to realize power output channel's silence control, eliminate the instantaneous popping that arouses when power 1 switches and the gain switches.
Furthermore, the power control, gain control, volume control, mute control and other functions are all controlled by the MCU at the front end of the player.
The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.
Claims (10)
1. An earamp circuit using discrete components, comprising:
the device comprises a power supply control circuit, a player front end, a discrete earphone amplifying circuit and a mute control circuit, wherein the input end of the power supply control circuit is connected with a power supply, the first output end of the power supply control circuit outputs a first controllable power supply to the discrete earphone amplifying circuit under the control of an MCU circuit, the second output end of the power supply control circuit outputs a second controllable power supply to the player front end under the control of the MCU circuit, a volume control circuit is connected between the discrete earphone amplifying circuit and the player front end, and the discrete earphone amplifying circuit outputs a power output signal to the earphone output end through the mute control circuit;
the discrete earphone amplifying circuit is of a three-stage amplifying circuit structure and comprises a differential output input stage, a main voltage amplifying stage and a power amplifying output stage, wherein the differential output input stage is used for providing a first amplifying signal, the main voltage amplifying stage is used for providing a second amplifying signal, the power amplifying output stage is used for providing a third amplifying signal, the differential output input stage is connected with the main voltage amplifying stage, the main voltage amplifying stage is connected with the power amplifying output stage, and a voltage negative feedback circuit is connected between the differential output input stage and the power amplifying output stage.
2. The ear amplifier circuit of claim 1, wherein:
the front end of the player is used for decoding music playing signals and then outputting analog circuit audio signals to the volume control circuit, and the volume control circuit outputs preceding stage audio signals to the discrete earphone amplifying circuit for power amplification, so that a power output signal is formed.
3. The ear amplifier circuit of claim 1, wherein:
the circuitry also includes a user interface configured to display a menu system and receive input, the user interface being coupled to the player front end.
4. The ear amplifier circuit of claim 1, wherein:
the power supply control circuit comprises a DC/DC conversion chip, a first resistor is connected between a positive voltage power supply output pin VPOS and an FBP pin of the DC/DC conversion chip in a bridging mode, and a second resistor is connected between a negative voltage power supply output pin VNEG and an FBN pin of the DC/DC conversion chip in a bridging mode.
5. The ear amplifier circuit of claim 2, wherein:
the differential output input stage comprises a first constant current source, a first field effect tube and a second field effect tube, a grid electrode of the first field effect tube is connected to the preceding stage audio signal, a source electrode of the first field effect tube is connected with the first constant current source, a grid electrode of the second field effect tube is connected to the voltage negative feedback circuit, a source electrode of the second field effect tube is connected with the first constant current source, and drain electrodes of the first field effect tube and the second field effect tube are further connected with a first power type double triode.
6. The ear amplifier circuit of claim 5, wherein:
the main voltage amplification stage comprises a first triode, a bias circuit and a second constant current source, wherein the base electrode of the first triode is connected to the drain electrode of the first field effect transistor, the collector electrode of the first triode is connected with the bias circuit, and the bias circuit is connected with the second constant current source.
7. The ear amplifier circuit of claim 6, wherein:
the power amplification output stage comprises a second triode and a third triode, the second triode and the third triode are power type double triodes with twin structures, and the second triode and the third triode are connected in parallel to output.
8. The ear amplifier circuit of claim 7, wherein:
the second triode is a second power type triode, the third triode is a third power type triode, the bases of the two triodes of the second power type triode are connected to the voltage negative feedback circuit, the emitting electrodes of the two triodes of the second power type triode are respectively connected to the nodes A and B, the bases of the two triodes of the third power type triode are connected to the voltage negative feedback circuit, and the emitting electrodes of the two triodes of the third power type triode are respectively connected to the nodes A and B.
9. The ear amplifier circuit of claim 7, wherein:
the voltage negative feedback circuit comprises a first switch, a second switch, a third resistor, a fourth resistor and a fifth resistor, wherein the first end of the first switch is connected with the second end of the third resistor, the first end of the second switch is connected with the second end of the fourth resistor, the second end of the first switch and the second end of the second switch are respectively connected with the power supply control circuit, the first end of the third resistor is connected with the gate of the second field-effect tube, the first end of the fourth resistor is connected with the second end of the fifth resistor, and the first end of the fifth resistor is connected with the power output end of the power amplification output stage.
10. The ear amplifier circuit of claim 9, wherein:
the first switch and the second switch are analog switches FSA2275.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221607850.4U CN217770324U (en) | 2022-06-23 | 2022-06-23 | Ear discharge circuit using discrete elements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221607850.4U CN217770324U (en) | 2022-06-23 | 2022-06-23 | Ear discharge circuit using discrete elements |
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| Publication Number | Publication Date |
|---|---|
| CN217770324U true CN217770324U (en) | 2022-11-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221607850.4U Active CN217770324U (en) | 2022-06-23 | 2022-06-23 | Ear discharge circuit using discrete elements |
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| CN (1) | CN217770324U (en) |
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- 2022-06-23 CN CN202221607850.4U patent/CN217770324U/en active Active
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