阅读说明：本技术 音频信号混合输入电路、耳机及蓝牙音响 (Audio signal mixing input circuit, earphone and Bluetooth sound equipment ) 是由 易振强 王丽 于 2021-09-17 设计创作，主要内容包括：本发明公开了一种音频混合输入电路、耳机及蓝牙音响,涉及音频设备技术领域,其中音频混合输入电路包括耳放IC芯片、蓝牙IC芯片和Line输入接口。耳放IC芯片的第一输出端设置有第一喇叭,耳放IC芯片的第二输出端设置有第二喇叭；且蓝牙IC芯片的多个输出端分别通过不同的第一阻容输入耦合电路模块连接对应的耳放IC芯片的输入端,且在第一阻容输入耦合电路模块的输入端设置有接地负载电阻；Line输入接口的第一输出端和第二端分别通过不同的第二阻容输入耦合电路模块连接耳放IC芯片的第二输入端,且在第二阻容输入耦合电路模块的输入端设置有接地负载电阻。音频混合输入电路能够有效解决蓝牙音频信号和Line音频信号相互干扰的问题。(The invention discloses an audio mixing input circuit, an earphone and a Bluetooth sound box, and relates to the technical field of audio equipment. A first loudspeaker is arranged at the first output end of the ear-placing IC chip, and a second loudspeaker is arranged at the second output end of the ear-placing IC chip; a plurality of output ends of the Bluetooth IC chip are respectively connected with the input ends of the corresponding ear-discharge IC chips through different first resistance-capacitance input coupling circuit modules, and the input ends of the first resistance-capacitance input coupling circuit modules are provided with grounding load resistors; the first output end and the second end of the Line input interface are connected with the second input end of the ear-discharge IC chip through different second resistance-capacitance input coupling circuit modules respectively, and the input end of each second resistance-capacitance input coupling circuit module is provided with a grounding load resistor. The audio mixing input circuit can effectively solve the problem that the Bluetooth audio signal and the Line audio signal are mutually interfered.)

1. An audio signal mixing input circuit, comprising:

the ear-playing IC chip comprises a first input end, a second input end, a third input end and a fourth input end, wherein a first loudspeaker is arranged at a first output end of the ear-playing IC chip;

the Bluetooth IC chip is used for outputting a plurality of paths of Bluetooth audio signals, a plurality of output ends of the Bluetooth IC chip are respectively connected with a first input end, a second input end, a third input end and a fourth input end of the corresponding ear amplifier IC chip through different first resistance-capacitance input coupling circuit modules, and the input ends of the first resistance-capacitance input coupling circuit modules are provided with grounding load resistors;

the Line input interface is used for accessing a Line audio signal, a first output end of the Line input interface is connected with a second input end of the ear amplifier IC chip through a second resistance-capacitance input coupling circuit module, a second output end of the Line input interface is connected with a third input end of the ear amplifier IC chip through another second resistance-capacitance input coupling circuit module, and an input end of the second resistance-capacitance input coupling circuit module is provided with a grounding load resistor.

2. The audio signal mixing input circuit of claim 1, wherein the first rc input coupling circuit module and the second rc input coupling circuit module each comprise an input coupling capacitor and an input resistor connected in series in sequence, and the input resistor is further connected to the input terminal of the ear discharge IC chip.

3. The audio signal mixing input circuit according to claim 1, wherein a first feedback resistor is provided between the first input terminal and the first output terminal of the ear discharge IC chip.

4. The audio signal mixing input circuit according to claim 1, wherein a second feedback resistor is provided between the fourth input terminal and the second output terminal of the ear-discharge IC chip.

5. The audio signal mixing input circuit of claim 1, wherein a first input terminal of the first speaker is connected to a first output terminal of the ear-play IC chip, and a second input terminal of the first speaker is connected to the ear-play IC chip through a filtering module.

6. The audio signal mixing input circuit of claim 5, wherein the filtering module comprises a plurality of filtering capacitors connected in parallel.

7. An earphone characterized by comprising the audio signal mixing input circuit according to any one of claims 1 to 6.

8. A Bluetooth speaker comprising the audio signal mixing input circuit as claimed in any one of claims 1 to 6.

Technical Field

The invention relates to the field of audio equipment, in particular to an audio mixing input circuit, an earphone and a Bluetooth sound box.

Background

Currently, audio output of a bluetooth IC (Integrated Circuit) chip applied in the market is differential balanced output, while a Line audio signal of a 3.5mm earphone seat of a mobile phone or a PC (Personal Computer) is single-ended output, and in the related art, a bluetooth audio signal is generally converted into single-ended output, so that the Line audio signal and the bluetooth audio signal are compatible, but the adopted Circuit design is relatively complex and high in cost, noise is easily generated when the bluetooth differential balanced output is converted into the single-ended output, a speaker output signal-to-noise ratio is low, and mutual interference is easily generated when the bluetooth audio signal and the Line audio signal are mixed and input.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides an audio mixing input circuit, an earphone and a Bluetooth sound box, which can effectively solve the problem of mutual interference of Bluetooth audio signals and Line audio signals.

The audio hybrid input circuit according to the embodiment of the first aspect of the invention comprises an ear-playing IC chip, a Bluetooth IC chip for outputting multiple Bluetooth audio signals and a Line input interface for accessing Line audio signals. A first loudspeaker is arranged at a first output end of the ear amplifier IC chip, a second loudspeaker is arranged at a second output end of the ear amplifier IC chip, and the ear amplifier IC chip comprises a first input end, a second input end, a third input end and a fourth input end; a plurality of output ends of the Bluetooth IC chip are respectively connected with a first input end, a second input end, a third input end and a fourth input end of the corresponding ear-discharge IC chip through different first resistance-capacitance input coupling circuit modules, and the input ends of the first resistance-capacitance input coupling circuit modules are provided with grounding load resistors; the first output end of the Line input interface is connected with the second input end of the ear amplifier IC chip through a second resistance-capacitance input coupling circuit module, the second output end of the Line input interface is connected with the third input end of the ear amplifier IC chip through another second resistance-capacitance input coupling circuit module, and the input end of the second resistance-capacitance input coupling circuit module is provided with a grounding load resistor.

The audio mixing input circuit according to the embodiment of the invention has at least the following beneficial effects: through the grounding load resistor, the first resistance-capacitance input coupling circuit module and the second resistance-capacitance input coupling circuit module, the audio hybrid input circuit can effectively reduce the interference between the Bluetooth audio signal and the Line audio signal, so that the circuit can effectively output the Bluetooth audio signal and the Line audio signal, the user experience can be improved, and the audio hybrid input circuit is simple in structure and can effectively reduce the cost.

According to some embodiments of the present invention, the first rc input coupling circuit module and the second rc input coupling circuit module each include an input coupling capacitor and an input resistor connected in series in sequence, and the input resistor is further connected to an input terminal of the ear amplifier IC chip.

According to some embodiments of the present invention, a first feedback resistor is disposed between the first input terminal and the first output terminal of the ear discharge IC chip.

According to some embodiments of the invention, a second feedback resistor is disposed between the fourth input terminal and the second output terminal of the ear discharge IC chip.

According to some embodiments of the present invention, the first input terminal of the first speaker is connected to the first output terminal of the ear-drop IC chip, and the second input terminal of the first speaker is connected to the ear-drop IC chip through the filtering module.

According to some embodiments of the invention, the filter module comprises a plurality of filter capacitors connected in parallel.

A headset according to an embodiment of the second aspect of the invention comprises an audio mixing input circuit as described in the embodiment of the first aspect.

The earphone according to the embodiment of the invention has at least the following beneficial effects: the earphone can be compatible with Bluetooth audio signals and Line audio signals, can effectively reduce mutual interference between the Bluetooth audio signals and the Line audio signals, and improves the use experience of users.

The bluetooth sound equipment according to the third aspect of the present invention includes the audio mixing input circuit as described in the first aspect of the present invention.

The Bluetooth sound box provided by the embodiment of the invention at least has the following beneficial effects: the Bluetooth sound box can be compatible with Bluetooth audio signals and Line audio signals, meets the requirements of users, reduces mutual interference between the Bluetooth audio signals and the Line audio signals, and improves the use experience of the users.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic block diagram of an audio signal mixing input circuit according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an audio signal mixing input circuit according to an embodiment of the invention.

Reference numerals:

the earphone amplifier comprises an earphone amplifier IC chip 110, a Bluetooth IC chip 120, a Line input interface 130, a first loudspeaker 140 and a second loudspeaker 150; a first rc input coupling circuit module 210, a second rc input coupling circuit module 220, and a filtering module 230.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and more than, less than, more than, etc. are understood as excluding the present number, and more than, less than, etc. are understood as including the present number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Referring to fig. 1, in some embodiments of the present invention, an audio signal mixing input circuit is provided, which includes an ear-play IC chip 110, a bluetooth IC chip 120, and a Line input interface 130. A first output of the ear play IC chip 110 is provided with a first speaker 140 and a second output of the ear play IC chip 110 is provided with a second speaker 150, it being contemplated that the first speaker 140 and the second speaker 150 are used for playback of left channel and right channel audio, e.g., the first speaker 140 plays left channel audio and the second speaker 150 plays right channel audio. The ear drop IC chip 110 may be a CS4418 chip, a TD a1308 chip, or the like.

The bluetooth IC chip 120 outputs multiple bluetooth audio signals, that is, the bluetooth IC chip 120 has multiple output terminals, and each output terminal is connected to the input terminal of the ear amplifier IC chip 110 through the first rc input coupling circuit module 210, it can be understood that there are four input terminals of the ear amplifier IC chip 110, that is, a first input terminal, a second input terminal, a third input terminal and a fourth input terminal, the first output terminal of the bluetooth IC chip 120 is connected to the first input terminal of the ear amplifier IC chip 110 through the first rc input coupling circuit module 210, and similarly, other output terminals of the bluetooth IC chip 120 are connected to different input terminals of the ear amplifier IC chip 110 through different first rc input coupling circuit modules 210.

The Line input interface 130 is configured to access a Line audio signal, wherein a first output end of the Line input interface 130 is connected to a second input end of the ear-play IC chip 110 through a second rc input coupling circuit module 220, a second output end of the Line input interface 130 is connected to a third input end of the ear-play IC chip 110 through another second rc input coupling circuit module 220, it should be understood that both the second output end of the bluetooth IC chip 120 and the first output end of the Line input interface 130 are connected to the second input end of the ear-play IC chip 110, and both the third output end of the bluetooth IC chip 120 and the second output end of the Line input interface 130 are connected to the third input end of the ear-play IC chip 110. It should be noted that the Line input interface 130 is an interface for accessing Line audio signals, such as a 3.5mm Line input female socket.

And the input ends of each first rc input coupling circuit module 210 and each second rc input coupling circuit module 220 are connected with a grounding load resistor, it can be understood that a grounding load resistor is connected to each branch of the bluetooth IC chip 120 that outputs a bluetooth audio signal, and similarly, a grounding load resistor is provided to each branch of the Line input interface 130 that outputs a Line audio signal.

Through the grounding load resistor, the first resistance-capacitance input coupling circuit module 210 and the second resistance-capacitance input coupling circuit module 220, the audio hybrid input circuit can effectively reduce the interference between the Bluetooth audio signal and the Line audio signal, so that the circuit can effectively output the Bluetooth audio signal and the Line audio signal, the user experience can be improved, the audio hybrid input circuit is simple in structure, and the cost can be effectively reduced.

In some embodiments of the present invention, the first rc input coupling circuit module 210 and the second rc input coupling circuit module 220 each include an input coupling capacitor and an input resistor connected in series. One end of the input coupling capacitor in the first rc input coupling circuit module 210 is connected to the output end of the bluetooth IC chip 120, and one end of the input resistor is connected to the ear-play IC chip 110, that is, the bluetooth audio signal output by the bluetooth IC chip 120 enters the ear-play IC chip 110 through the input coupling capacitor and the input resistor. The input coupling capacitor in the second rc input coupling circuit module 220 is connected to the output terminal of the Line input interface 130, and the input resistor is connected to the input terminal of the ear-play IC chip 110, that is, the Line audio signal passes through the coupling capacitor and then enters the ear-play IC chip 110 through the input resistor.

In some embodiments of the present invention, a first feedback resistor is disposed between the first input terminal and the first output terminal of the ear-amplifying IC chip 110, that is, a first end of the first feedback resistor is connected to the first input terminal of the ear-amplifying IC chip 110, and a second end of the first feedback resistor is connected to the first output terminal of the ear-amplifying IC chip 110, and it is contemplated that the first end of the first feedback resistor is connected to the output terminal of the first rc input-coupled circuit module 210.

In some embodiments of the present invention, a second feedback resistor is disposed between the fourth input terminal and the second output terminal of the ear-amplifying IC chip 110, that is, a first terminal of the second feedback resistor is connected to the fourth input terminal of the ear-amplifying IC chip 110, and a second terminal of the first feedback resistor is connected to the second output terminal of the ear-amplifying IC chip 110, and it is contemplated that the first terminal of the first feedback resistor is connected to the output terminal of the first rc input-coupled circuit module 210.

In some embodiments of the present invention, the input terminal of the first speaker 140 is connected to the first output of the ear-play IC chip 110, and the output terminal of the first speaker 140 is connected to the ear-play IC chip 110 through the filtering module 230. The filtering module 230 filters the power end of the ear-play IC chip 110, that is, after the power end of the ear-play IC chip 110 is connected to the power end of the ear-play IC chip 110, the power end of the filtering module 230 is connected to the power end of the ear-play IC chip 110, and the second end of the filtering module 230 is connected to the ground protection end of the ear-play IC chip 110 and the output end of the first speaker 140.

In some embodiments of the present invention, the filtering module 230 includes a plurality of filtering capacitors connected in parallel, for example, three filtering capacitors are disposed in the filtering module 230 and connected in parallel, a first end of each filtering capacitor is connected to the power supply and the power supply terminal of the ear-amp IC chip 110, and a second end of each filtering capacitor is connected to the output terminal of the first speaker 140 and the protection ground terminal of the ear-amp IC chip 110. It should be noted that the number of the filter capacitors connected in parallel in the filter module 230 may be set according to the filtering requirement of the circuit.

In some embodiments of the present invention, the audio signal mixing input circuit includes an ear-play IC chip 110, a bluetooth IC chip 120, a Line input interface 130, a first speaker 140, and a second speaker 150.

Specifically, referring to fig. 2, the bluetooth IC chip U2 outputs four bluetooth audio signals including a left channel signal including BT _ LN and BT _ LP and a right channel signal including BT _ RN and BT _ RP. The BT _ LN signal is connected with a first input end of an ear discharge IC chip U1 through an input coupling capacitor C5 and an input resistor R1, and a grounding load resistor R11 is connected in front of the input coupling capacitor C5; the BT _ LP signal is connected with a second input end of the ear discharge IC chip U1 through an input coupling capacitor C6 and an input resistor R2, and a grounding load resistor R10 is connected in front of the input coupling capacitor C6; the BT _ RN signal is connected to the third input terminal of the ear discharge IC chip U1 through an input coupling capacitor C10 and an input resistor R6, and a ground load resistor R13 is connected in front of the input coupling capacitor C10; the BT _ RP signal is connected to the fourth input terminal of the ear-discharge IC chip U1 through the input coupling capacitor C11 and the input resistor R7, and the ground load resistor R12 is connected in front of the input coupling capacitor C11.

For the Line input interface JK1, after a Line audio signal is accessed, the Line input interface JK1 outputs Line _ LIN and Line _ RIN signals, the Line _ LIN signal is connected with a second input end of the ear-discharge IC chip U1 through an input coupling capacitor C7 and an input resistor R3, and a grounding load resistor R16 is connected in front of the input coupling capacitor C7; the INE _ RIN signal input coupling capacitor C9 and the input resistor R5 are connected to the second input terminal of the ear discharge IC chip U1, and a ground load resistor R17 is connected in front of the input coupling capacitor C9.

A first feedback resistor R4 is connected between a first input end and a first output end of the ear-discharge IC chip U1, and a second feedback resistor R20 is connected between a fourth input end and a second output end of the ear-discharge IC chip U1. The first input and the fourth input of the ear amplifier IC chip U1 are negative inputs, which are equivalent to inverting inputs in the operational amplifier, and the second input and the third input of the ear amplifier IC chip U1 are positive inputs, which are equivalent to non-inverting inputs in the operational amplifier.

The first output end of the ear playing IC chip U1 is connected with a first loudspeaker SPKL, the first loudspeaker SPKL is used for playing left channel audio, the second output end of the ear playing IC chip U1 is connected with a second loudspeaker SPKR, and the second loudspeaker SPKR is used for playing right channel audio. The input end of the first loudspeaker SPKL is connected to the first output end of the ear-play IC chip U1, the output end of the first loudspeaker SPKL is connected to the protection ground end of the ear-play IC chip U1, wherein the power supply end and the protection ground end of the ear-play IC chip U1 are connected to the filter module 230 formed by connecting the filter capacitor C1, the filter capacitor C2 and the filter capacitor C3 in parallel, that is, the power supply PVDD is connected to the first end of the filter module 230, and the first loudspeaker SPKL is connected to the second end of the filter module 230.

It can be understood that, a left channel signal in the bluetooth audio signal is input to the ear-play IC chip U1 through the coupling input capacitor C5, the input resistor R1, the coupling input capacitor C6, and the input resistor R2, amplified by the ear-play IC chip U1, and output to the first speaker SPKL; the right channel signal in the bluetooth audio signal is respectively input to the ear-playing IC chip U1 through the coupling input capacitor C10, the input resistor R6, the coupling input capacitor C11 and the input resistor R7, and is amplified by the ear-playing IC chip U1 and then output to the second speaker SPKR.

A left channel signal of a Line audio signal is input into an ear-playing IC chip U1 through a coupling input capacitor C7 and an input resistor R3, amplified through an ear-playing IC chip U1 and then output to a first loudspeaker SPKL; the right channel signal of the Line audio signal is input to the ear-play IC chip U1 through the coupling input capacitor C9 and the input resistor R5, amplified by the ear-play IC chip U1, and output to the second speaker SPKR.

When the Bluetooth is not connected or the Bluetooth is connected and stops playing audio, the Bluetooth audio signal is disconnected, which affects the signal size of the Line audio signal input to the ear-play IC chip U1, i.e. interference is formed, while the circuit design in the invention can input the left channel signal of the Line audio signal to the ear-play IC chip U1 under the voltage division effect of the input resistor R3, the input resistor R2 and the grounding load resistor R10, and the right channel signal of the Line audio signal can be input to the ear-play IC chip U1 under the voltage division effect of the input resistor R5, the input resistor R6 and the grounding load resistor R13, so that the interference effect of the Bluetooth audio signal on the Line audio signal is reduced.

When the Line audio signal is not input, the left channel signal of the bluetooth audio signal can be input into the ear-play IC chip U1 under the voltage division effect of the input resistor R2, the input resistor R3 and the ground load resistor R16, and the right channel signal of the bluetooth audio signal can be input into the ear-play IC chip U1 under the voltage division effect of the input resistor R6, the input resistor R5 and the ground load resistor R17, so that the interference influence of the Line audio signal on the bluetooth audio signal is reduced.

In some embodiments of the present invention, an earphone is provided, where the earphone includes the audio mixing input circuit described in the above embodiments, and the earphone is capable of being compatible with a bluetooth audio signal and a Line audio signal, and is capable of effectively reducing mutual interference between the bluetooth audio signal and the Line audio signal, that is, capable of effectively reducing interference influence of bluetooth audio signal input on Line audio signal input and interference influence of Line audio signal input on bluetooth audio signal input, and improving user experience.

In some embodiments of the present invention, a bluetooth sound device is provided, where the bluetooth sound device includes the audio mixing input circuit as described in the above embodiments, and it is contemplated that the bluetooth sound device can also be compatible with a bluetooth audio signal and a Line audio signal, so as to adapt to user requirements, reduce mutual interference between the bluetooth audio signal and the Line audio signal, and improve user experience.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.