Audio circuit, chip and electronic equipment

Abstract

The invention provides an audio circuit, a chip and electronic equipment, and relates to the technical field of audio. The circuit works in an environment with radio frequency radiation of at least two frequency bands and comprises an audio power amplifier and two audio transmission circuits, each audio transmission circuit comprises a wire, an inductor, a capacitor and a diode, the first end of each diode is connected with the output end of the audio power amplifier, and the second end of each diode is grounded. The first end of the capacitor is connected with the first end of the diode, the second end of the capacitor is grounded, the first end of the inductor is connected with the first end of the capacitor, and the second end of the inductor is connected with the first end of the wire; the diode and the capacitor carry out noise suppression and electrostatic protection on the original signal to obtain an audio signal which is output by a wire; the inductor blocks a part of radio frequency energy, and the inductor and the capacitor form a low-pass filter to block the residual radio frequency energy, so that the radio frequency energy cannot be transmitted to the diode. Therefore, the performance of the audio circuit and the performance of the radio frequency module are ensured, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the field of audio technology, and in particular to an audio circuit, a chip and an electronic device. Background Art

[0002] With the development of science and technology, the functions that electronic products can achieve are becoming more and more complex, and the internal structure is also becoming more and more complex. Taking mobile phones as an example, the audio module is an electronic component integrated inside the mobile phone that is responsible for audio signal processing, transmission and playback, and can meet users' needs for music, communication and other aspects.

[0003] Currently, in order to provide electrostatic protection for an audio power amplifier (Audio PA) in an audio module and suppress the working noise of the Audio PA, devices such as magnetic beads, capacitors, and diodes are usually added to the circuit of the audio module.

[0004] However, multiple modules in mobile phones, such as RF modules and audio modules, often need to work at the same time. In a complex working environment, the wires used to connect the speakers in the audio module will be affected by RF radiation. If there are two RF energies of different frequency bands transmitted to the diode along the wires, due to the nonlinear characteristics of the diode, the two RF energies of different frequency bands will generate intermodulation noise in the diode. The intermodulation noise will be radiated along the wires and received by the RF module, thereby affecting the performance of the RF module, resulting in a decline in device performance and a poor user experience. Summary of the invention

[0005] The present application provides an audio circuit, chip and electronic device to solve the problem that if there are two radio frequency energies of different frequency bands transmitted to the diode along the wire, due to the nonlinear characteristics of the diode, the radio frequency energies of the two different frequency bands will generate intermodulation noise in the diode, and the intermodulation noise will be radiated along the wire and received by the radio frequency module, thereby affecting the performance of the radio frequency module, resulting in a decline in device performance and a poor user experience. Thus, on the basis of ensuring the performance of the audio module, the coexistence of the audio module and the radio frequency module is achieved, the influence of the audio module on the performance of the radio frequency module is avoided, the device performance is improved, and the user experience is improved.

[0006] In a first aspect, the present application provides an audio circuit, wherein the audio circuit operates in a first environment, wherein there is radio frequency radiation of at least two frequency bands in the first environment, and the audio circuit comprises: an audio power amplifier and two audio transmission circuits, wherein the audio power amplifier comprises two output terminals, wherein the two output terminals respectively output original signals, the audio transmission circuit is connected to the output terminals, and the audio transmission circuit comprises a wire, an inductor, a capacitor, and a diode, wherein a first end of the diode is connected to the output terminal, a second end of the diode is grounded, a first end of the capacitor is connected to a first end of the diode, a second end of the capacitor is grounded, a first end of the inductor is connected to a first end of the capacitor, and a second end of the inductor is connected to a first end of the wire;

[0007] The diode and the capacitor are used to perform noise suppression and electrostatic protection processing on the original signal to obtain the audio signal;

[0008] The inductor is used to block a first portion of the radio frequency energy. The inductor and the capacitor form a low-pass filter to block a second portion of the radio frequency energy so that the radio frequency energy cannot be transmitted to the diode. The radio frequency energy is energy generated by the radio frequency radiation of the at least two frequency bands received by the conductor when working in the first environment.

[0009] The wire is used to output the audio signal.

[0010] The audio circuit provided by the first aspect works in a first environment, and there is radio frequency radiation of at least two frequency bands in the first environment. The audio circuit includes: an audio power amplifier and two audio transmission circuits. The audio power amplifier includes two output terminals, and the two output terminals respectively output original signals. The audio transmission circuit is connected to the output terminals. The audio transmission circuit includes a wire, an inductor, a capacitor and a diode. The first end of the diode is connected to the output terminal, the second end of the diode is grounded, the first end of the capacitor is connected to the first end of the diode, the second end of the capacitor is grounded, the first end of the inductor is connected to the first end of the capacitor, and the second end of the inductor is connected to the first end of the wire, so that the original signal can be subjected to noise suppression and electrostatic protection processing through the diode and the capacitor to obtain an audio signal, and the audio signal is output from the wire, thereby realizing the audio output function. By adding inductance near the conductor of the audio circuit, the first part of the radio frequency energy generated by radio frequency radiation of at least two frequency bands is blocked. By exchanging the positions of the original capacitors, the newly added inductance and the original capacitors form a low-pass filter, which blocks the second part of the radio frequency energy generated by radio frequency radiation of at least two frequency bands. As a result, the radio frequency energy generated by radio frequency radiation of at least two frequency bands cannot be transmitted to the diode, thereby preventing the radio frequency energy from reaching the diode in the audio transmission circuit, thereby preventing the diode from generating intermodulation noise, and further avoiding affecting the radio frequency module. While ensuring the performance of the audio transmission circuit, the performance of the radio frequency module is also guaranteed, thereby improving the performance of the device and the user experience.

[0011] In a possible design, the audio transmission circuit further includes: magnetic beads, and the magnetic beads are used to suppress low-frequency noise of the original signal.

[0012] In one possible design, the first end of the magnetic bead is connected to the output end, and the second end of the magnetic bead is connected to the first end of the diode; or, the first end of the magnetic bead is connected to the first end of the diode, and the second end of the magnetic bead is connected to the first end of the capacitor.

[0013] In one possible design, the diode is a transient voltage suppressor diode.

[0014] In one possible design, the capacitance of the capacitor is 100 pico-farads.

[0015] In a possible design, the index of the inductance is:

[0016] The reference DC resistance value is less than or equal to 0.2 ohms;

[0017] The sensitivity value is greater than or equal to 30 nanohenries and less than or equal to 160 nanohenries;

[0018] The rated current is greater than or equal to 800 mA.

[0019] In a possible design, the inductance of the inductor is 110 nanohenries.

[0020] In a second aspect, the present application provides an audio module, comprising: a speaker and an audio circuit in the first aspect and any possible design of the first aspect, wherein the speaker comprises two input terminals;

[0021] The second end of the wire in the audio transmission circuit is connected to the input end.

[0022] The beneficial effects of the audio module provided in the second aspect and each possible design of the second aspect can be referred to the beneficial effects brought about by the first aspect and each possible implementation method of the first aspect, and will not be repeated here.

[0023] In a third aspect, the present application provides a chip, comprising: the audio circuit in the first aspect and any possible design of the first aspect.

[0024] In a fourth aspect, the present application provides an electronic device, comprising: at least one radio frequency module and an audio module in the second aspect and any possible design of the second aspect.

[0025] In a fifth aspect, the present application provides an electronic device, comprising: at least one radio frequency module and a chip in the third aspect and any possible design of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the structure of an audio module provided in one embodiment of the present application.

[0028] Figure 2 A schematic diagram of the structure of an audio circuit provided in one embodiment of the present application.

[0029] Figure 3 A schematic diagram of the structure of an audio circuit provided in one embodiment of the present application.

[0030] Figure 4 A schematic diagram of the structure of an audio circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0031] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0033] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In related technologies, such as Figure 1 As shown, there are two audio transmission circuits between the audio power amplifier Audio PA in the audio module and the speaker, one of which is connected to the positive output terminal VOP of the audio power amplifier Audio PA, and the other is connected to the negative output terminal VON of the audio power amplifier Audio PA. The audio output circuit connected to the positive output terminal VOP includes: a magnetic bead B1, a capacitor C1, a diode T1 and a wire D1, and the audio output circuit connected to the negative output terminal VON includes: a magnetic bead B2, a capacitor C2, a diode T2 and a wire D2.

[0035] The audio power amplifier Audio PA outputs audio signals through the positive output terminal VOP and the negative output terminal VON, the magnetic bead B1 / magnetic bead B2 and the capacitor C1 / capacitor C2 can suppress the noise generated when the audio power amplifier Audio PA is working, the diode T1 / diode T2 can provide electrostatic protection for the circuit, and the audio signal is transmitted to the speaker via the wire.

[0036] exist Figure 1 In the figure, the portion framed by the dotted line is usually integrated on the main board, and the wire D1 / wire D2 is connected to one end of the diode T1 / diode T2 on the main board. In order to ensure that the speaker can be connected, the length of the wire D1 / wire D2 is usually longer.

[0037] However, the working environment of the audio module is relatively complex, and there are usually multiple modules working together. For example, in mobile phones, computers and other devices, RF modules such as Bluetooth (BT) modules, wireless local area networks (WLAN) modules, near field communication (NFC) modules, and wireless wide area network (WWAN) modules work simultaneously with audio modules. Figure 1 In the example, RF module 1 and RF module 2 work simultaneously with the audio module, and the receiving frequency bands of RF module 1 and RF module 2 are different. If there are two RF radiations of different frequency bands, wire D1 / wire D2 will be affected by the RF radiations of two different frequency bands, and the RF energy generated by the RF radiations of two different frequency bands will be transmitted to diode T1 / diode T2 along wire D1 / wire D2. Due to the nonlinear characteristics of the diode, the RF energy generated by the RF radiations of two different frequency bands will generate intermodulation noise in diode T1 / diode T2, and the intermodulation noise will be radiated along the wire. When RF module 1 and RF module 2 perform receiving operations, if the frequency of the intermodulation noise falls within the receiving frequency range of RF module 1 or RF module 2, it will affect the receiving sensitivity of the RF module, thereby affecting the performance of the RF module, resulting in a decline in device performance and a poor user experience.

[0038] Based on this, the present application provides an audio circuit, an audio module, a chip and an electronic device. By adding an inductor near the conductor of the audio transmission circuit and changing the position of the capacitor, the capacitor and the inductor form a low-pass filter, so that the inductor and the low-pass filter block the radio frequency energy, preventing the radio frequency energy from reaching the diode in the audio transmission circuit, thereby preventing the diode from generating intermodulation noise, and then avoiding affecting the radio frequency module, while ensuring the performance of the audio transmission circuit, the performance of the radio frequency module is also guaranteed, the equipment performance is improved, and the user experience is improved.

[0039] The audio circuit provided in the present application can be applied to electronic devices with audio modules and radio frequency modules, such as mobile phones, tablet computers, desktop computers, laptop computers and speakers.

[0040] Below, an audio circuit provided by the present application is introduced with reference to specific examples.

[0041] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of an audio circuit provided by an embodiment of the present application. Figure 2 As shown, the audio circuit includes: an audio power amplifier 10 and two audio transmission circuits.

[0042] Wherein, the audio circuit works in the first environment, and there are at least two frequency bands of radio frequency radiation in the first environment. Wherein, the frequency band refers to the receiving frequency band of the radio frequency module, and the radio frequency module can use the receiving frequency band to perform a receiving operation. The radio frequency radiation of at least two frequency bands can be generated by a radio frequency module using at least two different frequency bands for receiving and sending operations, or it can be generated by multiple different radio frequency modules using at least two different frequency bands for receiving and sending operations. For example, in an environment where radio frequency module 1 and radio frequency module 2 work simultaneously with the audio module, when radio frequency module 1 works in one frequency band, radio frequency radiation of the frequency band will be generated, and when radio frequency module 2 works in another frequency band, radio frequency radiation of the other frequency band will be generated. Such as in the above-mentioned mobile phones, computers and other devices. It should be noted that the number of radio frequency modules in the first environment can be one or more, and this application does not limit this.

[0043] The radio frequency module may be, for example, a BT module, a WLAN module, an NFC module or a WWAN module.

[0044] The model of the audio power amplifier 10 may be LM386, STA510F or TDA2050.

[0045] The audio power amplifier 10 includes two output terminals, and the two output terminals output original signals respectively.

[0046] Among them, one output end of the audio power amplifier 10 is a negative output end, and the other output end is a positive output end. The negative output end outputs a negative-phase original signal, and the positive output end outputs a positive-phase original signal. For ease of explanation, the negative output end is recorded as output end VON, and the positive output end is recorded as output end VOP. The audio transmission circuit connected to the output end VON is recorded as audio transmission circuit 20, and the audio transmission circuit connected to the output end VOP is recorded as audio transmission circuit 30. The original signal input to the audio transmission circuit 20 is recorded as a first original signal, and the original signal input to the audio transmission circuit 30 is recorded as a second original signal.

[0047] Among them, the original signal is the original audio signal amplified by the audio power amplifier 10, and the original audio signal can be a signal generated by a processor. For example, in a mobile phone, the processor can process the audio file to obtain the original audio signal and input it into the audio power amplifier 10.

[0048] The audio transmission circuit 20 and the audio transmission circuit 30 have the same structure, thereby ensuring that the original signal of the negative phase and the original signal of the positive phase can be processed simultaneously.

[0049] Next, the structure of the audio transmission circuit 20 / audio transmission circuit 30 will be described in detail.

[0050] The audio transmission circuit includes a conductor, an inductor, a capacitor, and a diode. For ease of explanation, the conductor in the audio transmission circuit 20 is recorded as a first conductor 21, the inductor is recorded as a first inductor 22, the capacitor is recorded as a first capacitor 23, and the diode is recorded as a first diode 24. The conductor in the audio transmission circuit 30 is recorded as a second conductor 31, the inductor is recorded as a second inductor 32, the capacitor is recorded as a second capacitor 33, and the diode is recorded as a second diode 34. The audio signal output by the audio transmission circuit 20 is recorded as a first audio signal, and the audio signal output by the audio transmission circuit 30 is recorded as a second audio signal.

[0051] The first end of the first diode 24 is connected to the output terminal VON, the second end of the first diode 24 is grounded, the first end of the first capacitor 23 is connected to the first end of the first diode 24, the second end of the first capacitor 23 is grounded, the first end of the first inductor 22 is connected to the first end of the first capacitor 23, and the second end of the first inductor 22 is connected to the first end of the first wire 21. The first end of the second diode 34 is connected to the output terminal VOP, the second end of the second diode 34 is grounded, the first end of the second capacitor 33 is connected to the first end of the second diode 34, the second end of the second capacitor 33 is grounded, the first end of the second inductor 32 is connected to the first end of the second capacitor 33, and the second end of the second inductor 32 is connected to the first end of the second wire 31.

[0052] Among them, the audio power amplifier 10, the first inductor 22, the first capacitor 23, the first diode 24, the second inductor 32, the second capacitor 23, and the second diode 34 in the audio circuit can be integrated on the main board of the device, and the first wire 21 / the second wire 31 is connected to the second end of the first inductor 22 / the second inductor 32 integrated on the main board of the device.

[0053] The first diode 24 and the first capacitor 23 are used to perform noise suppression and electrostatic protection processing on the first original signal to obtain a first audio signal. The second diode 34 and the second capacitor 33 are used to perform noise suppression and electrostatic protection processing on the second original signal to obtain a second audio signal.

[0054] When the first original signal / the second original signal flows through the first diode 24 / the second diode 34, if there is a surge pulse voltage or the surge pulse voltage is greater than the breakdown voltage of the first diode 24 / the second diode 34, the first diode 24 / the second diode 34 can reversely break down, thereby achieving electrostatic protection.

[0055] In some examples, the first diode 24 and the second diode 34 are transient voltage suppressor diodes (TVS). TVS is an overvoltage protection device with bidirectional voltage stabilization characteristics and bidirectional negative resistance characteristics, which can suppress instantaneous overvoltage. When a surge pulse voltage appears in the audio transmission circuit, the surge pulse voltage is greater than the breakdown voltage of the TVS, so that the TVS can be Zener-broken, changing from a high-resistance state to a low-resistance state, shunting and clamping the surge voltage, thereby protecting the components in the audio output circuit from being damaged by the surge pulse voltage, thereby achieving electrostatic protection.

[0056] When the first diode 24 and the second diode 34 are TVS, the first end of the first diode 24 is the anode of the TVS, and the second end of the first diode 24 is the cathode of the TVS. The first end of the second diode 34 is the anode of the TVS, and the second end of the second diode 34 is the cathode of the TVS.

[0057] When the first original signal / the second original signal flows through the first capacitor 23 / the second capacitor 33, the first capacitor 23 / the second capacitor 33 can suppress high-frequency noise in the first original signal / the second original signal.

[0058] In some examples, the capacitance of the first capacitor 23 is 100 pF, and the capacitance of the second capacitor 33 is 100 pF.

[0059] Based on this, the first diode 24 / the second diode 34, and the first capacitor 23 / the second capacitor 33 can process the first original signal / the second original signal, filter out the high-frequency noise in the original signal, and perform electrostatic protection on the audio transmission circuit 20 / the audio transmission circuit 30, thereby obtaining the first audio signal / the second audio signal, which is output through the first wire 21 / the second wire 31.

[0060] The second end of the first wire 21 / the second wire 31 can be connected to a speaker ( Figure 2 The audio signal is converted into sound that can be received by the user.

[0061] Since there is at least two frequency bands of radio frequency radiation in the first environment, the first wire 21 / second wire 31 working in the first environment receives at least two frequency bands of radio frequency radiation and generates at least two frequency bands of radio frequency energy, that is, the first wire 21 / second wire 31 receives at least two frequency bands of radio frequency energy.

[0062] For example, taking the case where the RF module 1 and the RF module 2 and the audio circuit work simultaneously in the first environment, the RF module 1 transmits RF energy with a frequency of F1, and the RF module 2 transmits RF energy with a frequency of F2. After being received by the first wire 21 / the second wire 31, they are transmitted to the first diode 24 / the second diode 34. Based on the nonlinear characteristics of the diode, an intermodulation component with a frequency of F=mF1±nF2 will be generated on the first diode 24 / the second diode 34. The intermodulation component will be radiated along the first wire 21 / the second wire 31, and will be received by the antennas on the RF module 1 and the RF module 2. If the frequency F of the intermodulation component falls within the receiving frequency band of the RF module 1 or the receiving frequency band of the RF module 2, it will affect the sensitivity of the RF module 1 or the RF module 2.

[0063] For example, the receiving frequency band of the RF module 1 is 746 MHz-756 MHz. If the frequency F of the intermodulation component is 750 MHz, the RF module 1 will receive the intermodulation component, thereby affecting the operation of the RF module 1 and interfering with the sensitivity of the RF module 1.

[0064] Based on this, by adding an inductor to the audio circuit and changing the position of the capacitor, the RF energy is blocked. Specifically, the RF energy received by the first wire 21 flows through the first inductor 22, and the first inductor 22 can block the first part of the RF energy received by the first wire 21. The first inductor 22 and the first capacitor 23 form a low-pass filter, which can block the second part of the RF energy, that is, the remaining RF energy after being blocked by the first inductor 22. Therefore, the RF energy cannot be transmitted to the first diode 24.

[0065] Similarly, the RF energy received by the second wire 31 flows through the second inductor 32, and the second inductor 32 can block the first part of the RF energy received by the second wire 31. The low-pass filter formed by the second inductor 32 and the second capacitor 33 can block the second part of the RF energy, that is, the remaining RF energy after being blocked by the second inductor 32. Therefore, the RF energy cannot be transmitted to the second diode 34.

[0066] Based on this, by using the characteristics of inductance blocking high frequencies and passing low frequencies, the inductance is directly connected in series with the wire, which can block part of the RF energy received by the wire. By changing the original capacitor position, the capacitor and inductance form a low-pass filter to block the remaining RF energy, so that the RF energy cannot be transmitted to the diode, and the capacitor of the audio circuit can be reused to further block the RF energy through the capacitor, without adding more additional devices, thus saving costs.

[0067] The first wire 21 is used to output a first audio signal, and the second wire 31 is used to output a second audio signal.

[0068] Since the frequency of the audio signal is generally low, and the inductor has the characteristic of blocking high frequencies and passing low frequencies, the first inductor 22 / the second inductor 32 will not affect the first audio signal / the second audio signal, so that the first audio signal / the second audio signal can be output by the first wire 21 / the second wire 31, while blocking the radio frequency energy and ensuring the performance of the audio circuit.

[0069] In an embodiment of the present application, the audio circuit operates in a first environment, and there is radio frequency radiation of at least two frequency bands in the first environment. The audio circuit includes: an audio power amplifier and two audio transmission circuits. The audio power amplifier includes two output ends, and the two output ends respectively output original signals. The audio transmission circuit is connected to the output end. The audio transmission circuit includes a wire, an inductor, a capacitor and a diode. The first end of the diode is connected to the output end, the second end of the diode is grounded, the first end of the capacitor is connected to the first end of the diode, the second end of the capacitor is grounded, the first end of the inductor is connected to the first end of the capacitor, and the second end of the inductor is connected to the first end of the wire, so that the original signal can be subjected to noise suppression and electrostatic protection processing through the diode and the capacitor to obtain an audio signal, and the audio signal is output from the wire, thereby realizing the audio output function. By adding inductance near the conductor of the audio circuit, the first part of the radio frequency energy generated by radio frequency radiation of at least two frequency bands is blocked. By exchanging the positions of the original capacitors, the newly added inductance and the original capacitors form a low-pass filter, which blocks the second part of the radio frequency energy generated by radio frequency radiation of at least two frequency bands. As a result, the radio frequency energy generated by radio frequency radiation of at least two frequency bands cannot be transmitted to the diode, thereby preventing the radio frequency energy from reaching the diode in the audio transmission circuit, thereby preventing the diode from generating intermodulation noise, and further avoiding affecting the radio frequency module. While ensuring the performance of the audio transmission circuit, the performance of the radio frequency module is also guaranteed, thereby improving the performance of the device and the user experience.

[0070] Based on the above exemplary description, Figure 2On the basis of , the audio transmission circuit further includes: magnetic beads. For the convenience of description, the magnetic beads in the audio transmission circuit 20 are recorded as first magnetic beads 25, and the magnetic beads in the audio transmission circuit 30 are recorded as second magnetic beads 35.

[0071] The first magnetic bead 25 is used to suppress the low-frequency noise of the first original signal, and the second magnetic bead 35 is used to suppress the low-frequency noise of the second original signal.

[0072] Magnetic beads are a type of device made of magnetic material that has the characteristics of high resistance and low inductance. When a signal passes through a magnetic bead, it will produce a hysteresis effect, thereby achieving filtering. Magnetic beads with high magnetic permeability and high magnetic resistance have a better filtering effect on low-frequency noise.

[0073] Based on this, adding magnetic beads to the audio transmission circuit can further suppress the low-frequency noise of the original signal, thereby improving the quality of the obtained audio signal, ensuring the performance of the audio circuit, and further improving the user experience.

[0074] Based on the above exemplary description, the following Figure 3 and Figure 4 , introduces various connection methods of magnetic beads in audio transmission circuits.

[0075] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of an audio circuit provided by an embodiment of the present application. Figure 3 As shown:

[0076] A first end of the first magnetic bead 25 is connected to the output end VON, and a second end of the first magnetic bead 25 is connected to a first end of the first diode 24 .

[0077] A first end of the second magnetic bead 35 is connected to the output end VOP, and a second end of the second magnetic bead 35 is connected to a first end of the second diode 34 .

[0078] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an audio circuit provided by an embodiment of the present application. Figure 4 As shown:

[0079] A first end of the first magnetic bead 25 is connected to a first end of the first diode 24 , and a second end of the first magnetic bead 25 is connected to a first end of the first capacitor 23 .

[0080] A first end of the second magnetic bead 35 is connected to a first end of the second diode 34 , and a second end of the second magnetic bead 35 is connected to a first end of the second capacitor 33 .

[0081] Based on this, the capacitor and the magnetic bead can jointly suppress the noise of the original signal, thereby improving the quality of the obtained audio signal and ensuring the performance of the audio circuit. The magnetic bead is set between the diode and the capacitor, which can further suppress the RF energy from reaching the diode, thereby further blocking the RF energy, which is beneficial to improving the performance of the device.

[0082] Based on the above exemplary description, the indicators of the first inductor 22 and the second inductor 32 meet the following specifications:

[0083] 1. The reference DC resistance value is less than or equal to 0.2 ohms;

[0084] 2. The sensitivity value is greater than or equal to 30 nanohenries and less than or equal to 160 nanohenries;

[0085] 3. The rated current is greater than or equal to 800 mA.

[0086] Based on this, the first inductor 22 and the second inductor 32 meet the requirements of blocking radio frequency energy without affecting the performance of the audio circuit, thereby ensuring the accuracy of blocking radio frequency energy and further improving the performance of the device.

[0087] In some examples, the first inductor 22 and the second inductor 32 may be selected to have an inductance of 110 nanohenry, which further improves the accuracy of blocking radio frequency energy.

[0088] Next, the effect of the above audio circuit is explained through an experiment in a Universal Mobile Telecommunications System Terrestrial Radio Access Network New Radio Dual Connectivity (EN-DC) combined downlink EN-DC configuration: DC_13A_n77A.

[0089] The transmitting and receiving bands of the frequency band B13 of the 4th generation mobile communication technology (4G) are:

[0090] TX: 777MHz-787 MHz;

[0091] RX:746MHz-756 MHz.

[0092] The transmitting and receiving frequency bands of the fifth-generation mobile communication technology (5G) frequency band n77 are:

[0093] TX: 3300MHz-4200 MHz;

[0094] RX: 3300MHz-4200 MHz.

[0095] The sensitivity of RF module A when working in band B13 alone was -91.2dBm. When RF module A was working in band B13, RF module B was working in band n77, and the existing audio module was working at the same time, the sensitivity of RF module A was -78.2dBm, and the sensitivity was deteriorated by 13.6dB.

[0096] According to the receiving frequency band of band B13 and the transmitting frequency band of band n77 and band B13, we can know that:

[0097] 746MHz=3854MHz-777MHz*4;

[0098] 756MHz=3864MHz-777MHz*4;

[0099] That is, the intermodulation components generated by the fourth harmonic of the fundamental wave of frequency band B13 on the diode and the fundamental wave of frequency band n77 on the diode fall into the receiving frequency band of frequency band B13, thereby interfering with the sensitivity of RF module A when working in frequency band B13.

[0100] Through the audio circuit provided by this application, the RF module A is tested using the frequency band B13 and the RF module B is tested using the frequency band n77. When working simultaneously with the audio circuit provided by this application, the sensitivity of the RF module A is -91.5dBm. It can be seen that the difference in sensitivity when the RF module A is tested alone using the frequency band B13 is small, and the sensitivity error is within an acceptable range, thereby avoiding affecting the performance of the RF module, and ensuring the performance of the RF module while ensuring the performance of the audio transmission circuit, thereby improving the performance of the device and the user experience.

[0101] Illustratively, the present application also provides an audio module, which includes: a speaker and an audio circuit provided in any of the above embodiments.

[0102] The speaker includes two input terminals, including a negative input terminal and a positive input terminal, wherein the negative input terminal is used to receive the first audio signal, and the positive input terminal is used to receive the second audio signal.

[0103] The second end of the first wire 21 in the audio transmission circuit 20 is connected to the negative input terminal, and the second end of the second wire 22 in the audio transmission circuit 30 is connected to the positive input terminal.

[0104] It should be noted that the audio module of the embodiment of the present application can be used to implement the technical solution of the above-mentioned audio circuit embodiment. Its implementation principle and technical effect are similar and will not be repeated here.

[0105] Illustratively, the present application also provides a chip that integrates the audio circuit provided by any of the above embodiments.

[0106] Illustratively, an embodiment of the present application further provides an electronic device, comprising: at least one radio frequency module and the chip provided by the aforementioned embodiment.

[0107] Illustratively, an embodiment of the present application further provides an electronic device, comprising: at least one radio frequency module and the audio module provided by the aforementioned embodiment.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed circuits, modules, and devices can be implemented in other ways. For example, the circuit embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0109] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0110] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An audio circuit, characterized in that: The audio circuit works in a first environment, and there is radio frequency radiation of at least two frequency bands in the first environment. The audio circuit comprises: an audio power amplifier and two audio transmission circuits, the audio power amplifier comprises two output terminals, and the two output terminals respectively output original signals, the audio transmission circuit is connected to the output terminals, and the audio transmission circuit comprises a wire, an inductor, a capacitor and a diode, the first terminal of the diode is connected to the output terminal, the second terminal of the diode is grounded, the first terminal of the capacitor is connected to the first terminal of the diode, the second terminal of the capacitor is grounded, the first terminal of the inductor is connected to the first terminal of the capacitor, and the second terminal of the inductor is connected to the first terminal of the wire; The diode and the capacitor are used to perform noise suppression and electrostatic protection processing on the original signal to obtain the audio signal; The inductor is used to block a first portion of the radio frequency energy. The inductor and the capacitor form a low-pass filter to block a second portion of the radio frequency energy so that the radio frequency energy cannot be transmitted to the diode. The radio frequency energy is energy generated by the radio frequency radiation of the at least two frequency bands received by the conductor when working in the first environment. The wire is used to output the audio signal.

2. The circuit according to claim 1, characterized in that The audio transmission circuit further includes: magnetic beads, and the magnetic beads are used to suppress low-frequency noise of the original signal.

3. The circuit according to claim 2, characterized in that The first end of the magnetic bead is connected to the output end, and the second end of the magnetic bead is connected to the first end of the diode; or, the first end of the magnetic bead is connected to the first end of the diode, and the second end of the magnetic bead is connected to the first end of the capacitor.

4. The circuit according to any one of claims 1 to 3, characterized in that: The diode is a transient voltage suppressor diode.

5. The circuit according to any one of claims 1 to 3, characterized in that: The capacitance of the capacitor is 100 pF.

6. The circuit according to any one of claims 1 to 3, characterized in that: The index of the inductance is: The reference DC resistance value is less than or equal to 0.2 ohms; The sensitivity value is greater than or equal to 30 nanohenries and less than or equal to 160 nanohenries; The rated current is greater than or equal to 800 mA.

7. The circuit according to claim 6, characterized in that The inductance value of the inductor is 110 nanohenries.

8. An audio module, characterized in that: include: A loudspeaker and an audio circuit as claimed in any one of claims 1 to 7; the loudspeaker comprises two input terminals, and the second end of the wire in the audio transmission circuit is connected to the input terminal.

9. A chip, characterized in that: include: The audio circuit according to any one of claims 1 to 7.

10. An electronic device, characterized in that: include: at least one radio frequency module and the audio module of claim 8; Alternatively, at least one radio frequency module and the chip as claimed in claim 9.

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