CN203574819U - Earphone circuit and earphone - Google Patents

Abstract

The embodiment of the utility model discloses an earphone circuit and earphone, wherein the circuit is composed of discrete components. By adopting the utility model, the earphone circuit can filter the noise of the audio signal, so that the earphone of mobile terminals such as mobile phones and tablet computers has good anti-interference performance, improves the practicality of the earphone in an environment with interference signals and improves the user experience.

Description

A kind of earphone circuit and earphone

technical field

The utility model relates to the field of electronic technology, in particular to an earphone circuit and an earphone.

Background technique

When mobile terminals such as mobile phones and tablet computers are in the conduction or radiation interference signals loaded by the outside world, the signal output by the mobile phone earphones often appears noise due to the interference of the external interference signals, which affects the audio quality and reduces the user experience effect. Moreover, due to the low anti-interference ability of the earphones of mobile terminals such as mobile phones and tablet computers, they cannot meet the international standard EMC certification, making mobile terminals such as mobile phones and tablet computers unable to obtain the qualifications for international market access, thereby limiting the sales market of manufacturers and reducing producer's economic interests.

Utility model content

The embodiment of the utility model provides an earphone circuit and an earphone, which can improve the anti-interference performance of an earphone end of a mobile terminal and improve user experience.

An earphone circuit provided by an embodiment of the present invention, the circuit includes a microphone internal circuit, a microphone external circuit, a ground terminal, an earphone signal output circuit, a first filter circuit, and a second filter circuit;

One end of the first filter circuit is connected to one end of the internal circuit of the microphone, the other end of the first filter circuit is connected to one end of the external circuit of the microphone, another end of the first filter circuit is connected to the microphone The other end of the internal circuit is respectively connected to the ground terminal;

One end of the second filter circuit is connected to the signal end of the earphone signal output circuit, the other end of the second filter circuit is connected to the other end of the microphone external circuit, and the ground end of the earphone signal output circuit is connected to the The ground terminal is connected.

An earphone provided by an embodiment of the utility model includes the earphone circuit and an earphone housing according to the above objective, and the earphone circuit is built in the earphone housing.

Embodiments of the utility model have the following beneficial effects:

The earphone circuit of the embodiment of the utility model improves the resistance of the earphone circuit by adding a first filter circuit between the microphone internal circuit and the microphone external circuit, and adding a second filter circuit between the microphone external circuit and the earphone input/output circuit. Interference capability; In addition, the earphone circuit has a simple structure, is safe and reliable, and improves user experience.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative work.

Fig. 1 is a circuit schematic diagram of an earphone circuit provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of an earphone provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. . Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to FIG. 1 , which is an earphone circuit provided by an embodiment of the present invention. As shown in FIG. 1 , the circuit 10 includes a microphone (MIC) internal circuit 100 , a microphone external circuit 200 , a ground terminal 300 , an earphone signal output circuit 400 , a first filter circuit 500 and a second filter circuit 600 .

One end of the first filter circuit 500 is connected to one end of the microphone internal circuit 100, the other end of the first filter circuit 500 is connected to one end of the microphone external circuit 200, and the first filter circuit 500 and the microphone external circuit 200 are connected. The other end of the internal circuit of the microphone is connected to the ground terminal 300 respectively;

One end of the second filter circuit 600 is connected to the signal end of the earphone signal output circuit 400, the other end of the second filter circuit 600 is connected to the other end of the microphone external circuit 200, and the earphone signal output circuit The ground end of 400 is connected to the ground end 300 .

Further, it also includes:

Left channel circuit 700 and right channel circuit 800;

One end of the left channel circuit 700 is connected to the left channel end of the earphone signal output circuit 400, one end of the right channel circuit 800 is connected to the right channel end of the earphone signal output circuit 400, the The other end of the left channel circuit 700 and the other end of the right channel circuit 800 are respectively connected to the ground terminal.

Further, the first filtering circuit 500 includes:

Resistor R2 and capacitor C1;

One end of the resistor R2 is connected to one end of the microphone internal circuit 100, and the other end of the resistor R2 is connected to one end of the microphone external circuit 200;

One end of the capacitor C1 is connected to the other end of the resistor R2 , and the other end of the capacitor C1 is connected to the ground terminal 300 .

Further, in the embodiment of the present invention, the second filter circuit 600 includes:

Bead B1 and resistor R1;

One end of the resistor R1 is connected to the signal end of the earphone signal output circuit 400, the other end of the resistor R1 is connected to one end of the magnetic bead B1, and the other end of the magnetic bead B1 is connected to the microphone external circuit 200 connections. Wherein, the resistance value of the resistor R1 ranges from 470Ω to 2000Ω. The resistance value of the magnetic bead B1 at 100MHz can be 1kΩ, 1.8kΩ or 2.5kΩ.

Further, the second filter circuit 700 also includes:

Inductor L and resistor R1;

One end of the resistor R1 is connected to the signal end of the earphone signal output circuit 400, the other end of the resistor R1 is connected to one end of the inductor L, and the other end of the inductor L is connected to the microphone external circuit 200 . Wherein, the inductance value of the inductor L may be 0˜100 nH. The resistance value of the resistor R1 ranges from 470Ω to 2000Ω.

The internal circuit 100 of the microphone may include a power supply, a field effect tube, a sound-to-electricity converter, and the like.

The working principle of the earphone circuit 10 will be described in detail below with reference to FIG. 1 .

When the earphone connected to the terminal device is in the conduction or radiation interference signal loaded by the outside world, the interference signal may be conducted from the microphone of the earphone into the earphone circuit and the ground terminal in the form of current or voltage. This interference may be common The mode may also be a differential mode. If there is no filter circuit in the earphone circuit to filter out the interference signal, the interference signal will enter the earphone circuit, which will affect the quality of the audio signal carried by the earphone circuit, causing the audio signal to fluctuate and carry noise. Therefore, in order to obtain a high-quality audio signal, it is necessary to filter the interference signal conducted into the microphone of the earphone.

In the earphone circuit 10, the first filter circuit 500 filters out the high-frequency pulse interference signal conducted from the microphone of the earphone, wherein, the resistor R2 and the capacitor C1 of the first filter circuit 500 form an RC filter circuit, and the audio signal Carried noise is filtered out. This enables the earphone of the mobile terminal to have an anti-interference capability and ensures audio quality.

Furthermore, under external radiation interference, most of the interference signals are high-frequency pulse interference signals of certain specific frequencies. If only the first filter circuit 500 filters the high-frequency pulse interference signal, it may not be able to completely filter out or filter out most of the interference signals, so in order to improve the anti-interference performance of the circuit, it is necessary The frequency band at the place is used for targeted filtering. In the earphone circuit, the second filter circuit 600 can purposely filter out certain high-frequency pulse interference signals of specific frequencies, so as to better filter out the interference signals. For example: under external radiation interference, most of the interference signals entering the earphone microphone are interference signals of about 100 MHz, and the second filter circuit 600 can filter out the interference signals of about 100 MHz. When the interference signal enters the earphone microphone and passes into the anti-interference circuit, in the process of the interference signal passing through the second filter circuit 600, the interference signal of about 100 MHz will be filtered out by the second filter circuit, and the remaining other frequency bands will be filtered out by the second filter circuit. The interference signal will be filtered by the first filter circuit 500 . Through the combined circuit of the first filter circuit 500 and the second filter circuit 600, the anti-interference ability of the earphone can be effectively improved.

Wherein, the second filter circuit 600 may be a filter circuit composed of a magnetic bead B1 and a resistor R1. Wherein, the magnetic bead B1 converts the high-frequency interference signal carried by the audio signal into heat energy so as to filter out the high-frequency interference signal. Further, the resistor R1 can change the impedance of the circuit, reduce the interference current and share the voltage, so that the second filter circuit 600 can play a better filtering role in low frequency filtering. Among them, the resistance value of the magnetic bead at 100MHz can be: 1kΩ, 1.8kΩ or 2.5kΩ, and the resistance value of the resistor can be 470Ω～2000Ω. Specifically, 500Ω, 800Ω, 1000Ω, 1500Ω or 1800Ω can be selected according to the filtering needs.

Further, the second filter circuit 600 may also be a second filter circuit 600 composed of an inductor L and a resistor R1. Wherein, the inductance value of the inductor L may be 100NH.

Further, the audio signal output by the earphone signal output circuit 400 can output the left channel audio or the right channel audio through the left channel circuit 700 or the right channel circuit 800, so that the user listens through the left and right earpieces of the earphone.

The working principle of the earphone circuit 10 will be described in detail below with reference to FIG. 1 .

When the mobile terminal is in the conduction or radiation interference signal loaded by the outside, the interference signal may affect the stability of the current or voltage in the PCB board of the terminal, causing it to fluctuate and generate noise. The audio signal output from the mobile terminal to the earphone may also carry interference signals due to current or voltage instability in the PCB board of the mobile terminal. Then, when the earphone signal output circuit 400 of the earphone circuit 10 receives the audio signal input by the mobile terminal, in order to obtain a high-quality audio signal, it needs to filter the audio signal output by the earphone signal output circuit 400 . When the headphone signal output circuit 400 outputs the audio signal to the first filter circuit 500, the first filter circuit 500 filters out the high-frequency pulse interference signal carried by the audio signal to reduce the noise of the audio signal.

Furthermore, the audio signal input by the mobile terminal to the earphone may also be interfered by a specific interference line and thus carry interference signals of certain specific frequencies. Therefore, it is necessary to filter out interference signals of certain specific frequencies for the audio signal, so as to better to improve audio quality. For example: the audio signal is affected by external interference so that the audio signal carries a 100MHz interference signal. When the audio signal is filtered by the first filter circuit 500 and output by the microphone external circuit 200 , the audio signal passes through the second filter circuit 600 to filter out the interference signal of a specific frequency carried by the audio signal.

Wherein, the resistor R2 and the capacitor C1 of the first filter circuit 500 form an RC filter circuit to filter out the noise carried by the audio signal. This enables the earphone of the mobile terminal to have an anti-interference capability and ensures audio quality.

Wherein, the second filter circuit 600 may be a filter circuit composed of a magnetic bead B1 and a resistor R1. Wherein, the magnetic bead B1 converts the high-frequency interference signal carried by the audio signal into heat energy so as to filter out the high-frequency interference signal. Further, the resistor R1 can change the impedance of the circuit, reduce the interference current and share the voltage, so that the second filter circuit 600 can play a better filtering role in low frequency filtering. Among them, the resistance value of the magnetic bead at 100MHz can be: 1kΩ, 1.8kΩ or 2.5kΩ, and the resistance value of the resistor can be 470Ω～2000Ω. Specifically, 500Ω, 800Ω, 1000Ω, 1500Ω or 1800Ω can be selected according to the filtering needs.

Further, the second filter circuit 600 may also be a second filter circuit 600 composed of an inductor L and a resistor R1. Wherein, the inductance value of the inductor L may be 100NH.

Further, the audio signal output by the earphone signal output circuit 400 can output the left channel audio or the right channel audio through the left channel circuit 700 or the right channel circuit 800, so that the user can Right earpiece to listen.

From the above, we can understand that by adding the first filter circuit between the microphone internal circuit and the microphone external circuit, and adding the second filter circuit between the microphone external circuit and the earphone input/output circuit, the performance of the earphone circuit 10 is improved. Anti-interference ability, so that the product can pass the CS and RS tests of international EMS certification.

The modules or units described in the embodiments of the present invention can be realized by a general-purpose integrated circuit, such as a CPU (Central Processing Unit, central processing unit), or by an ASIC (Application Specific Integrated Circuit, application-specific integrated circuit).

Please refer to FIG. 2 , which is a schematic structural diagram of an earphone provided by an embodiment of the present invention, which includes an earphone housing 20 and an earphone circuit. The earphone circuit here can be the earphone circuit 10 of the above embodiment, and the earphone circuit 10 has on the earphone housing 20 .

To sum up, the headphone circuit 10 and the headphone of the present invention have a simple structure, and are safe and reliable. By adding a first filter circuit between the microphone internal circuit and the microphone external circuit of the earphone circuit 10, and adding a second filter circuit between the microphone external circuit and the earphone input/output circuit, the anti-interference ability of the earphone circuit 10 is improved, The earphone can filter the noise of the audio signal and have good anti-interference performance, which improves the practicability of the earphone in the environment with interference signals and improves the user experience, thus gaining market recognition. At the same time, redundant circuit devices are removed, thereby reducing production costs.

The modules or units described in the embodiments of the present utility model can be integrated, further divided or deleted according to actual needs.

What is disclosed above is only a preferred embodiment of the utility model, and of course it cannot limit the scope of rights of the utility model. Therefore, equivalent changes made according to the claims of the utility model still fall within the scope of the utility model.

Claims (10)

1. An earphone circuit, characterized in that, the circuit comprises a microphone internal circuit, a microphone external circuit, a ground terminal, an earphone signal output circuit, a first filter circuit and a second filter circuit; One end of the first filter circuit is connected to one end of the internal circuit of the microphone, the other end of the first filter circuit is connected to one end of the external circuit of the microphone, another end of the first filter circuit is connected to the microphone The other end of the internal circuit is respectively connected to the ground terminal; One end of the second filter circuit is connected to the signal end of the earphone signal output circuit, the other end of the second filter circuit is connected to the other end of the microphone external circuit, and the ground end of the earphone signal output circuit is connected to the The ground terminal is connected. the 2. The earphone circuit according to claim 1, further comprising a left channel circuit and a right channel circuit; One end of the left channel circuit is connected to the left channel end of the earphone signal output circuit, one end of the right channel circuit is connected to the right channel end of the earphone signal output circuit, and the left channel circuit The other end of the right channel circuit and the other end of the right channel circuit are respectively connected to the ground. the 3. The earphone circuit according to claim 2, wherein the first filtering circuit comprises: Resistor R2 and capacitor C1; One end of the resistor R2 is connected to one end of the internal circuit of the microphone, and the other end of the resistor R2 is connected to one end of the external circuit of the microphone; One end of the capacitor C1 is connected to the other end of the resistor R2, and the other end of the capacitor C1 is connected to the ground. the 4. The earphone circuit according to claim 3, wherein the second filtering circuit comprises: Bead B1 and resistor R1; One end of the resistor R1 is connected to the signal end of the earphone signal output circuit, the other end of the resistor R1 is connected to one end of the magnetic bead B1, and the other end of the magnetic bead B1 is connected to the external circuit of the microphone . the 5 . The earphone circuit according to claim 4 , wherein the resistance value of the magnetic bead B1 at 100 MHz is 1 kΩ, 1.8 kΩ or 2.5 kΩ. the 6. The earphone circuit according to claim 4, characterized in that, the resistance range of the resistor R1 is between 470Ω-2000Ω. the 7. earphone circuit as claimed in claim 3, is characterized in that, described second filtering circuit also comprises: Inductor L and resistor R1; One end of the resistor R1 is connected to the signal end of the earphone signal output circuit, the other end of the resistor R1 is connected to one end of the inductor L, and the other end of the inductor L is connected to the external circuit of the microphone. the 8. The earphone circuit according to claim 7, wherein the inductance of the inductor L is 100nH. the 9. The earphone circuit according to claim 7, wherein the resistance value of the resistor R1 ranges from 470Ω to 2000Ω. the 10. An earphone, characterized in that it comprises the earphone circuit according to any one of claims 1 to 8 and an earphone housing, wherein the earphone circuit is built in the earphone housing. the

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