Audio circuits, chips and electronic devices

Abstract

The application provides an audio circuit, a chip and an electronic device, 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. The audio transmission circuit comprises a wire, an inductor, a capacitor and a diode. The first end of the diode is connected to the output end of the audio power amplifier, 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. The diode and the capacitor perform noise suppression and electrostatic protection on an original signal to obtain an audio signal, and the audio signal is output by the wire. The inductor prevents part of radio frequency energy, and the inductor and the capacitor form a low-pass filter to prevent the remaining 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 at the same time, and the user experience is improved.

Description

Technical Field

[0001] This application relates to the field of audio technology, and more particularly to an audio circuit, chip, and electronic device. Background Technology

[0002] With the development of technology, electronic products are becoming increasingly complex in their functions and internal structures. Taking mobile phones as an example, the audio module is an electronic component integrated inside the phone that is responsible for audio signal processing, transmission, and playback, meeting users' needs for music, communication, and other aspects.

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

[0004] However, multiple modules in a mobile phone, such as the radio frequency (RF) module and the audio module, often need to operate simultaneously. In complex working environments, the wires used to connect the speaker in the audio module are affected by RF radiation. If two different frequency bands of RF energy are transmitted to the diode through the wires, due to the nonlinear characteristics of the diode, the two different frequency bands of RF energy will generate intermodulation noise in the diode. This intermodulation noise will then be radiated out through the wires and received by the RF module, thus affecting the performance of the RF module, leading to a decrease in device performance and a poor user experience. Summary of the Invention

[0005] This application provides an audio circuit, chip, and electronic device to solve the problem that when two different frequency bands of radio frequency (RF) energy are transmitted to a diode via a wire, intermodulation noise will be generated in the diode due to the nonlinear characteristics of the diode. This intermodulation noise will then be radiated out through the wire and received by the RF module, thus affecting the performance of the RF module, leading to a decrease in device performance and a poor user experience. Therefore, this application achieves the coexistence of the audio module and the RF module while ensuring the performance of the audio module, avoiding the impact of the audio module on the RF module performance, improving device performance, and enhancing the user experience.

[0006] In a first aspect, this application provides an audio circuit that operates in a first environment where at least two frequency bands of radio frequency radiation exist. The audio circuit includes an audio power amplifier and two audio transmission circuits. The audio power amplifier includes two output terminals that output raw signals respectively. The audio transmission circuits are connected to the output terminals and include a wire, an inductor, a capacitor, and a diode. The first terminal of the diode is connected to the output terminal, and the second terminal of the diode is grounded. The first terminal of the capacitor is connected to the first terminal of the diode, and 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.

[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 the first part of the radio frequency energy. The inductor and the capacitor form a low-pass filter to block the second part of the radio frequency energy, so that the radio frequency energy cannot be transmitted to the diode. The radio frequency energy is the energy generated by the wire receiving radio frequency radiation of the at least two frequency bands when it is working in the first environment.

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

[0010] The audio circuit provided in the first aspect operates in a first environment where at least two frequency bands of radio frequency radiation exist. The audio circuit includes an audio power amplifier and two audio transmission circuits. The audio power amplifier has two output terminals, each outputting a raw signal. The audio transmission circuits are connected to the output terminals and include wires, inductors, capacitors, and diodes. The first terminal of the diode is connected to the output terminal, and the second terminal of the diode is grounded. The first terminal of the capacitor is connected to the first terminal of the diode, and 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. Thus, the original signal can be subjected to noise suppression and electrostatic discharge protection processing through the diode and capacitor to obtain an audio signal. The audio signal is output from the wire, thereby realizing the audio output function. By adding an inductor near the conductor in the audio circuit, the first portion of the RF energy generated by RF radiation in at least two frequency bands is blocked. By swapping the positions of the original capacitors, the newly added inductor and the original capacitors form a low-pass filter, blocking the second portion of the RF energy generated by RF radiation in at least two frequency bands. This prevents the RF energy generated by RF radiation in at least two frequency bands from being transmitted to the diode, thus preventing the RF energy from reaching the diode in the audio transmission circuit. This avoids the diode generating intermodulation noise and thus avoids affecting the RF module. While ensuring the performance of the audio transmission circuit, the performance of the RF module is also guaranteed, thereby improving device performance and enhancing the user experience.

[0011] In one possible design, the audio transmission circuit further includes a ferrite bead for suppressing low-frequency noise in the original signal.

[0012] In one possible design, the first end of the magnetic bead is connected to the output terminal, 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 is 100 picofarads.

[0015] In one possible design, the inductor's specifications are:

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

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

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

[0019] In one possible design, the inductance value is 110 nanohenries.

[0020] In a second aspect, this application provides an audio module, including: a speaker and audio circuitry in the first aspect and any possible design of the first aspect, wherein the speaker includes 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 the various possible designs of the second aspect can be found in the first aspect and the various possible implementations of the first aspect, and will not be repeated here.

[0023] Thirdly, this application provides a chip, including: an audio circuit in the first aspect and any possible design of the first aspect.

[0024] Fourthly, this application provides an electronic device, including: at least one radio frequency module and an audio module in any possible design of the second aspect.

[0025] Fifthly, this 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. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an audio module provided in an embodiment of this application.

[0028] Figure 2 This is a schematic diagram of an audio circuit provided in one embodiment of this application.

[0029] Figure 3 This is a schematic diagram of an audio circuit provided in one embodiment of this application.

[0030] Figure 4 This is a schematic diagram of an audio circuit provided in one embodiment of this application. Detailed Implementation

[0031] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.

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

[0035] The audio power amplifier (Audio PA) outputs audio signals through its positive output terminal VOP and negative output terminal VON. Ferrite beads B1 / B2 and capacitors C1 / C2 suppress the noise generated when the audio power amplifier (Audio PA) is working. Diodes T1 / T2 provide electrostatic protection for the circuit. The audio signal is transmitted to the speaker via wires.

[0036] exist Figure 1 In the diagram, the portion highlighted by the dotted line is typically integrated onto the motherboard. Wires D1 and D2 are connected to one end of diodes T1 and T2 on the motherboard. To ensure a speaker can be connected, wires D1 and D2 are usually quite long.

[0037] However, the operating environment of audio modules is quite complex, often involving multiple modules working simultaneously. For example, in devices like mobile phones and computers, radio frequency modules such as Bluetooth (BT), Wireless Local Area Networks (WLAN), Near Field Communication (NFC), and Wireless Wide Area Network (WWAN) modules operate concurrently with the audio module. Figure 1 RF modules 1 and 2 operate simultaneously with the audio module, but they receive at different frequency bands. If two different frequency bands of RF radiation exist, wires D1 and D2 will be affected by these radiations, and the RF energy generated will be transmitted to diodes T1 and T2 via wires D1 and D2. Due to the non-linear characteristics of diodes, intermodulation noise will be generated in diodes T1 and T2, and this noise will be radiated outwards via the wires. If the frequency of this intermodulation noise falls within the receiving frequency range of either RF module 1 or RF module 2, it will affect the receiving sensitivity of the RF modules, thus impacting their performance, leading to decreased device performance and a poor user experience.

[0038] Based on this, this application provides an audio circuit, an audio module, a chip, and an electronic device. By adding an inductor near the conductor in the audio transmission circuit and changing the position of the capacitor, the capacitor and inductor form a low-pass filter. This allows the inductor and low-pass filter to block radio frequency (RF) energy, preventing RF energy from reaching the diodes in the audio transmission circuit. This avoids the diodes generating intermodulation noise, thus preventing it from affecting the RF module. While ensuring the performance of the audio transmission circuit, the performance of the RF module is also guaranteed, improving device performance and enhancing the user experience.

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

[0040] The following section, with specific examples, introduces an audio circuit provided in this application.

[0041] Please see Figure 2 , Figure 2 This is a schematic diagram of an audio circuit provided in one embodiment of this application. Figure 2 As shown, the audio circuit includes: an audio power amplifier 10 and two audio transmission circuits.

[0042] In this system, the audio circuit operates in a first environment where at least two frequency bands of radio frequency (RF) radiation exist. Each frequency band refers to the receiving frequency band of the RF module, which is capable of receiving data. The RF radiation in at least two frequency bands can be generated by a single RF module using at least two different frequency bands for receiving and transmitting, or it can be generated by multiple different RF modules using at least two different frequency bands for receiving and transmitting. For example, in an environment where RF module 1 and RF module 2 operate simultaneously with the audio module, RF module 1 generates RF radiation in one frequency band, and RF module 2 generates RF radiation in another frequency band when operating in a different frequency band. This is similar to devices such as mobile phones and computers. It should be noted that the number of RF modules in the first environment can be one or more, and this application does not limit this.

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

[0044] The audio power amplifier 10 can be of model such as LM386, STA510F, or TDA2050.

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

[0046] In this design, the audio power amplifier 10 has one negative output terminal and the other positive output terminal. The negative output terminal outputs the original signal in negative phase, and the positive output terminal outputs the original signal in positive phase. For ease of explanation, the negative output terminal is denoted as output terminal VON, and the positive output terminal is denoted as output terminal VOP. The audio transmission circuit connected to output terminal VON is denoted as audio transmission circuit 20, and the audio transmission circuit connected to output terminal VOP is denoted as audio transmission circuit 30. The original signal input to audio transmission circuit 20 is denoted as the first original signal, and the original signal input to audio transmission circuit 30 is denoted as the second original signal.

[0047] The original signal is the original audio signal amplified by the audio power amplifier 10. The original audio signal can be a signal generated by the processor, such as in a mobile phone, where the processor can process the audio file to obtain the original audio signal and input it to the audio power amplifier 10.

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

[0049] The structure of audio transmission circuit 20 / audio transmission circuit 30 will be described in detail below.

[0050] The audio transmission circuit includes wires, inductors, capacitors, and diodes. For ease of explanation, the wires in audio transmission circuit 20 are designated as first wire 21, the inductor as first inductor 22, the capacitor as first capacitor 23, and the diode as first diode 24. The wires in audio transmission circuit 30 are designated as second wire 31, the inductor as second inductor 32, the capacitor as second capacitor 33, and the diode as second diode 34. The audio signal output by audio transmission circuit 20 is designated as the first audio signal, and the audio signal output by audio transmission circuit 30 is designated as the second audio signal.

[0051] In this configuration, the first terminal of the first diode 24 is connected to the output terminal VON, and the second terminal of the first diode 24 is grounded. The first terminal of the first capacitor 23 is connected to the first terminal of the first diode 24, and the second terminal of the first capacitor 23 is grounded. The first terminal of the first inductor 22 is connected to the first terminal of the first capacitor 23, and the second terminal of the first inductor 22 is connected to the first terminal of the first wire 21. The first terminal of the second diode 34 is connected to the output terminal VOP, and the second terminal of the second diode 34 is grounded. The first terminal of the second capacitor 33 is connected to the first terminal of the second diode 34, and the second terminal of the second capacitor 33 is grounded. The first terminal of the second inductor 32 is connected to the first terminal of the second capacitor 33, and the second terminal of the second inductor 32 is connected to the first terminal 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 motherboard of the device, and the first wire 21 / second wire 31 are connected to the second end of the first inductor 22 / second inductor 32 integrated on the motherboard of the device.

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

[0054] When the first original signal / second original signal flows through the first diode 24 / 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 / second diode 34, the first diode 24 / second diode 34 can break down in reverse, thereby achieving electrostatic protection.

[0055] In some examples, the first diode 24 and the second diode 34 are transient voltage suppressor (TVS) diodes. A TVS is an overvoltage protection device with bidirectional voltage regulation and bidirectional negative resistance characteristics, capable of suppressing transient overvoltages. When a surge voltage occurs in the audio transmission circuit, if the surge voltage exceeds the TVS's breakdown voltage, the TVS can Zener breakdown, changing from a high-resistance state to a low-resistance state, thus shunting and clamping the surge voltage. This protects the components in the audio output circuit from damage by the surge voltage, thereby achieving electrostatic discharge (ESD) protection.

[0056] When the first diode 24 and the second diode 34 are TVS diodes, the first terminal of the first diode 24 is the positive terminal of the TVS diode, and the second terminal of the first diode 24 is the negative terminal of the TVS diode. The first terminal of the second diode 34 is the positive terminal of the TVS diode, and the second terminal of the second diode 34 is the negative terminal of the TVS diode.

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

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

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

[0060] The second end of the first wire 21 / second wire 31 can be connected to a speaker. Figure 2 (Illustrated by dashed lines), thereby converting the audio signal into sound that the user can receive.

[0061] Since there is radio frequency radiation in at least two frequency bands in the first environment, the first conductor 21 / second conductor 31 will generate radio frequency energy in at least two frequency bands when it receives radio frequency radiation in the first environment. That is, the first conductor 21 / second conductor 31 receives radio frequency energy in at least two frequency bands.

[0062] For example, taking the scenario where RF module 1 and RF module 2 operate simultaneously with the audio circuit in the first environment, RF module 1 transmits RF energy at a frequency of F1, and RF module 2 transmits RF energy at a frequency of F2. After being received by the first wire 21 / second wire 31, the RF energy is transmitted to the first diode 24 / 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 / second diode 34. This intermodulation component will be radiated out along the first wire 21 / second wire 31 and received by the antennas on RF module 1 and RF module 2. If the frequency F of the intermodulation component falls within the receiving frequency band of RF module 1 or RF module 2, it will affect the sensitivity of RF module 1 or RF module 2.

[0063] For example, if the receiving frequency range of RF module 1 is 746MHz-756MHz, and the frequency F of the intermodulation component is 750MHz, then RF module 1 will receive the intermodulation component, which will affect the operation of RF module 1 and interfere with the sensitivity of RF module 1.

[0064] Based on this, radio frequency (RF) energy is blocked by adding an inductor and changing the position of the capacitor in the audio circuit. Specifically, the RF energy received by the first wire 21 flows through the first inductor 22. The first inductor 22 blocks the first portion 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 blocks the second portion of the RF energy, i.e., the remaining RF energy after being blocked by the first inductor 22. Thus, the RF energy cannot be transmitted to the first diode 24.

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

[0066] Based on this, by utilizing the characteristic of inductors to block high frequencies and pass low frequencies, connecting the inductor directly in series with the wire can block a portion of the radio frequency (RF) energy received by the wire. By changing the position of the original capacitor, the capacitor and inductor form a low-pass filter, blocking the remaining RF energy. This prevents RF energy from being transmitted to the diode, allowing the capacitor in the audio circuit to be reused to further block RF energy without adding any additional components, thus saving costs.

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

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

[0069] In this embodiment, the audio circuit operates in a first environment where at least two frequency bands of radio frequency radiation exist. The audio circuit includes an audio power amplifier and two audio transmission circuits. The audio power amplifier has two output terminals, each outputting the original signal. The audio transmission circuits are connected to the output terminals and include a wire, an inductor, a capacitor, and a diode. The first end of the diode is connected to the output terminal, and the second end of the diode is grounded. The first end of the capacitor is connected to the first end of the diode, and 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. Thus, the original signal can be subjected to noise suppression and electrostatic discharge protection processing through the diode and capacitor to obtain an audio signal. The audio signal is output from the wire, thereby realizing the audio output function. By adding an inductor near the conductor in the audio circuit, the first portion of the RF energy generated by RF radiation in at least two frequency bands is blocked. By swapping the positions of the original capacitors, the newly added inductor and the original capacitors form a low-pass filter, blocking the second portion of the RF energy generated by RF radiation in at least two frequency bands. This prevents the RF energy generated by RF radiation in at least two frequency bands from being transmitted to the diode, thus preventing the RF energy from reaching the diode in the audio transmission circuit. This avoids the diode generating intermodulation noise and thus avoids affecting the RF module. While ensuring the performance of the audio transmission circuit, the performance of the RF module is also guaranteed, thereby improving device performance and enhancing the user experience.

[0070] Based on the above exemplary description, in Figure 2In addition to the above, the audio transmission circuit also includes a ferrite bead. For ease of explanation, the ferrite bead in the audio transmission circuit 20 is referred to as the first ferrite bead 25, and the ferrite bead in the audio transmission circuit 30 is referred to as the second ferrite bead 35.

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

[0072] A ferrite bead is a device made of magnetic material, characterized by high resistance and low inductance. When a signal passes through a ferrite bead, it exhibits hysteresis, thus achieving filtering. Ferrite beads with high permeability and high reluctance are particularly effective at filtering low-frequency noise.

[0073] Therefore, adding a ferrite bead to the audio transmission circuit can further suppress low-frequency noise in the original signal, thereby improving the quality of the obtained audio signal, ensuring the performance of the audio circuit, and thus further enhancing the user experience.

[0074] Based on the above exemplary description, the following is combined with Figure 3 and Figure 4 This paper introduces various connection methods for ferrite beads in audio transmission circuits.

[0075] Please see Figure 3 , Figure 3 This is a schematic diagram of an audio circuit provided in one embodiment of this application. Figure 3 As shown:

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

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

[0078] Please see Figure 4 , Figure 4 This is a schematic diagram of an audio circuit provided in one embodiment of this application. Figure 4 As shown:

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

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

[0081] Therefore, the capacitor and ferrite bead can jointly suppress noise in the original signal, thereby improving the quality of the obtained audio signal and ensuring the performance of the audio circuit. The ferrite bead, placed between the diode and the capacitor, can further suppress radio frequency energy from reaching the diode, thus further blocking radio frequency energy and improving device performance.

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

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

[0084] 2. Sensitivity greater than or equal to 30 nanohenries and less than or equal to 160 nanohenries;

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

[0086] Based on this, the first inductor 22 and the second inductor 32 meet the requirements for blocking radio frequency energy without affecting the performance of the audio circuit, 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 can be selected as inductors with an inductance of 110 nanohenries, which further improves the accuracy of blocking radio frequency energy.

[0088] The effect of the above audio circuit is illustrated below through an experiment in the Universal Mobile Telecommunications System Terrestrial Radio Access Network New RadioDual Connectivity (EN-DC) combined downlink EN-DC configuration as DC_13A_n77A.

[0089] The transmit and receive frequency bands of frequency band B13 in the fourth generation mobile communication technology (4G) are as follows:

[0090] TX: 777MHz-787MHz;

[0091] RX: 746MHz-756MHz.

[0092] The transmit and receive frequency bands of 5G (5th generation mobile communication technology) are as follows:

[0093] TX: 3300MHz-4200 MHz;

[0094] RX: 3300MHz-4200 MHz.

[0095] When RF module A operates alone in band B13, its sensitivity is -91.2 dBm. When RF module A (using band B13), RF module B (using band n77), and an existing audio module operate simultaneously, the sensitivity of RF module A is -78.2 dBm, a degradation of 13.6 dB.

[0096] Based on the receiving frequency band of band B13 and the transmitting frequency bands of band n77 and band B13, it can be known that:

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

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

[0099] The fourth harmonic generated by the fundamental frequency of band B13 on the diode and the intermodulation component generated by the fundamental frequency of band n77 on the diode fall into the receiving frequency band of band B13, thus interfering with the sensitivity of RF module A when it operates in band B13.

[0100] Using the audio circuit provided in this application, tests were conducted on RF module A operating in frequency band B13 and RF module B operating in frequency band n77. When both operate simultaneously with the audio circuit provided in this application, the sensitivity of RF module A is -91.5 dBm. This shows that the difference in sensitivity compared to when RF module A operates alone in frequency band B13 is small, and the sensitivity error is within an acceptable range. This avoids affecting the performance of the RF module, ensuring both the performance of the audio transmission circuit and the performance of the RF module, thereby improving device performance and enhancing the user experience.

[0101] For example, this application also provides an audio module, which includes: a speaker and audio circuitry as provided in any of the above embodiments.

[0102] The speaker includes two input terminals: a negative input terminal and a positive input terminal. 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 this application embodiment can be used to implement the technical solution of the above audio circuit embodiment, and its implementation principle and technical effect are similar, so it will not be repeated here.

[0105] For example, this application also provides a chip that integrates the audio circuit provided in any of the above embodiments.

[0106] For example, this application also provides an electronic device, including: at least one radio frequency module and the chip provided in the foregoing embodiments.

[0107] For example, this application also provides an electronic device, including: at least one radio frequency module and the audio module provided in the foregoing embodiments.

[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 merely illustrative. For instance, the division of modules or units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0109] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0110] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An audio circuit, characterized by The audio circuit works in a first environment, the first environment has at least two frequency bands of radio frequency radiation, the at least two frequency bands of radio frequency radiation are generated by one or more radio frequency modules in the first environment, and the audio circuit comprises: an audio power amplifier and two audio transmission circuits, the audio power amplifier comprises two output ends, the two output ends output original signals respectively, and the audio transmission circuit is connected with the output end, the audio transmission circuit comprises a wire, an inductor, a capacitor and a diode, a first end of the diode is connected with the output end, a second end of the diode is grounded, a first end of the capacitor is connected with the first end of the diode, a second end of the capacitor is grounded, a first end of the inductor is connected with the first end of the capacitor, and a second end of the inductor is connected with a first end of the wire. The diode and the capacitor are used for noise suppression and electrostatic protection processing of the original signal to obtain an audio signal. The inductor is used for blocking a first part of energy in radio frequency energy, and the inductor and the capacitor form a low-pass filter for blocking a second part of energy in the radio frequency energy, so that the radio frequency energy cannot be transmitted to the diode, the diode does not generate intermodulation noise affecting the one or more radio frequency modules, and the radio frequency energy is energy generated by the wire working in the first environment and receiving the at least two frequency bands of radio frequency radiation; wherein the second end of the inductor constitutes an input end of the low-pass filter, and the first end of the capacitor connected with the first end of the inductor constitutes an output end of the low-pass filter. The wire is used for outputting the audio signal. The audio transmission circuit further comprises a magnetic bead, the magnetic bead is used for suppressing low-frequency noise of the original signal, a first end of the magnetic bead is connected with the first end of the diode, and a second end of the magnetic bead is connected with the first end of the capacitor.

2. The circuit of claim 1, wherein, The diode is a transient voltage suppression diode.

3. The circuit of any one of claim 1, characterized in that, The capacitance value of the capacitor is 100 picofarads.

4. The circuit of any one of claim 1, characterized in that, The inductor has the following indexes: The reference direct current resistance value is less than or equal to 0.2 ohms; The inductance value is greater than or equal to 30 nanohenries and less than or equal to 160 nanohenries; The rated current value is greater than or equal to 800 milliamperes.

5. The circuit of claim 4, wherein, The inductance value of the inductor is 110 nanohenries.

6. An audio module, characterized by, Comprise: A loudspeaker and the audio circuit of any one of claims 1 to 5; the loudspeaker comprises two input ends, and a second end of the wire in the audio transmission circuit is connected with the input ends.

7. A chip, characterized by Comprise: The audio circuit of any one of claims 1 to 5.

8. An electronic device, comprising: Comprise: At least one radio frequency module and the audio module of claim 6; Or, at least one radio frequency module and the chip of claim 7.

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