Earphone amplifying circuit and earphone volume control device

Abstract

The embodiment of the utility model provides an earphone amplifying circuit and an earphone volume control device. The earphone amplification circuit comprises an input control module, a negative feedback module, a voltage amplification module, a current amplification module and a power supply module. The power supply module is connected with the voltage amplification module and the current amplification module and supplies power to the voltage amplification module and the current amplification module; the input control module is connected with the current amplification module through the voltage amplification module, and the negative feedback module is respectively connected with the output end of the current amplification module and the input end of the voltage amplification module. Thus, through the above structure, the earphone amplification circuit is connected between audio equipment (such as a smart phone and an MP3 player) and an earphone, sufficient current and voltage are provided for the earphone, and it is ensured that after being amplified, an audio signal is transmitted to the earphone with the characteristics of large current, wide frequency response and high conversion rate. Therefore, the earphone can work normally and exert the optimal tone quality performance.

Description

Technical Field

[0001] The present application relates to the field of audio amplification, and in particular to an earphone amplifier circuit and an earphone volume control device. Background Art

[0002] High-fidelity headphones (Hi-Fi Headphones), commonly referred to as HiFi headphones, are devices designed to highly restore sound. High-fidelity headphones are characterized by their ability to reproduce the original sound with extremely high fidelity, allowing listeners to enjoy a very comfortable and close-to-live music experience. Because their design goal is to provide sound quality as close to the studio level as possible, high-fidelity headphones usually have higher impedance and lower sensitivity, which means that high-fidelity headphones require more current to drive in order to achieve the ideal volume level and sound quality performance. However, the headphone output ports of many portable audio players or smartphones cannot provide sufficient current and voltage, resulting in the headphones being unable to fully realize their potential, which is manifested as insufficient output power, a narrow sound field, and limited dynamic range. Utility Model Content

[0003] In order to overcome the technical problems mentioned in the above technical background, an embodiment of the present application provides an earphone amplifier circuit, wherein the earphone amplifier circuit includes an input control module, a negative feedback module, a voltage amplifier module, a current amplifier module and a power supply module;

[0004] The power supply module is connected to the voltage amplification module and the current amplification module to supply power to the voltage amplification module and the current amplification module;

[0005] The input control module is connected to the current amplification module via the voltage amplification module, and the negative feedback module is connected to the output end of the current amplification module and the input end of the voltage amplification module respectively.

[0006] In a possible implementation, the input control module includes a first capacitor and a volume controller;

[0007] The first capacitor is connected in series with the volume controller;

[0008] The volume controller includes a first end, a second end and a control end. The first capacitor is connected to the first end of the volume controller. The second end of the volume controller is grounded. The control end of the volume controller is connected to the input end of the voltage amplification module.

[0009] In a possible implementation, the negative feedback module includes a second resistor and a third resistor, and the second resistor and the third resistor are connected in series;

[0010] One end of the second resistor and the third resistor connected in series is grounded, and the other end of the second resistor and the third resistor connected in series is connected to the output end of the current amplification module;

[0011] The input end of the voltage amplification module is connected between the second resistor and the third resistor.

[0012] In a possible implementation, the voltage amplification module includes a voltage operational amplifier, the voltage operational amplifier includes a non-inverting input terminal, an inverting input terminal and an output terminal, the non-inverting input terminal is connected to the control terminal of the volume controller, and the inverting input terminal is connected between the second resistor and the third resistor;

[0013] The output end of the voltage operational amplifier is connected to the current amplification module.

[0014] In a possible implementation, the current amplification module includes a current operational amplifier, which includes an input end and an output end, the input end of the current operational amplifier is connected to the output end of the voltage operational amplifier, and the output end of the current operational amplifier is used to drive the signal output.

[0015] In a possible implementation, the power supply module includes a first voltage output terminal and a second voltage output terminal; the voltage output by the first voltage output terminal is greater than the voltage output by the second voltage output terminal;

[0016] The first voltage output end is connected to the positive poles of the voltage operational amplifier module and the current amplifier module respectively, and the second voltage output end is connected to the negative poles of the voltage operational amplifier module and the current amplifier module respectively.

[0017] In a possible implementation, the current amplification module also includes a fourth resistor, the current operational amplifier also includes a bias end, one end of the fourth resistor is connected to the bias end of the current operational amplifier, and the other end of the fourth resistor is connected to the second voltage output end of the power supply module, and the fourth resistor is used to adjust the bandwidth of the current operational amplifier.

[0018] In a possible implementation, the power module further includes a first decoupling capacitor and a second decoupling capacitor, the first voltage output terminal is grounded through the first decoupling capacitor, and the second voltage output terminal is grounded through the second decoupling capacitor.

[0019] Another object of the present application is to provide a headphone volume control device, which includes an independently arranged left-channel headphone amplifier circuit and a right-channel headphone amplifier circuit, wherein the left-channel headphone amplifier circuit and the right-channel headphone amplifier circuit are implemented by using a plurality of the headphone amplifier circuits provided by the present application.

[0020] In a possible implementation, the headphone volume control device also includes an headphone socket arranged at the output end of the current amplification module in the left channel headphone amplifier circuit and the right channel headphone amplifier circuit, and the signal amplified by the left channel headphone amplifier circuit and the right channel headphone amplifier circuit is output to the headphone through the headphone socket.

[0021] Based on any of the above aspects, the headphone amplifier circuit and the headphone volume control device provided in the embodiments of the present application connect the headphone amplifier circuit between an audio device (such as a smart phone, an MP3 player) and the headphone to provide sufficient current and voltage for the headphone, thereby ensuring that the audio signal is transmitted to the headphone with the characteristics of large current, wide-band response and high conversion rate after amplification, thereby ensuring that the headphone can work normally and exert its best sound quality performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 One of the schematic diagrams of a headphone amplifier circuit provided in this embodiment;

[0024] Figure 2 A second schematic diagram of a headphone amplifier circuit provided in this embodiment;

[0025] Figure 3 This is a schematic diagram of a headphone volume control device provided by this embodiment.

[0026] Icons: 10-headphone amplifier circuit, 100-input control module, C1-first capacitor, R1-volume controller, 110-negative feedback module, R2-second resistor, R3-third resistor, 120-voltage amplifier module, IC1-voltage operational amplifier, 130-current amplifier module, IC2-current operational amplifier, R4-fourth resistor, 140-power module, C2-first decoupling capacitor, C3-second decoupling capacitor, 20-headphone volume control device, 200-left channel headphone amplifier circuit, 210-right channel headphone amplifier circuit, 220-headphone socket. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of this application, it should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] It should be noted that, in the absence of conflict, different features in the embodiments of the present application may be combined with each other.

[0032] In order to solve the technical problems mentioned in the above background technology, the inventor innovatively designed the following technical solution, and the specific implementation scheme of the present application will be described in detail below in conjunction with the accompanying drawings. A headphone amplifier circuit is located between an audio device (such as a smart phone, MP3) and a headphone. The audio signal passing through the headphone amplifier circuit 10 provides a wider dynamic range, lower distortion and other advantages compared to the original audio signal, and the headphone is driven by sufficient current to enable the headphone to work normally and exert its best sound quality performance. Therefore, when designing the structure of the headphone amplifier circuit 10, it is necessary to first consider designing a voltage amplification module and a current amplification module. The voltage amplification module performs preliminary amplification on the audio signal to provide sufficient voltage driving force for subsequent current amplification, while the current amplification module provides high current output, which is very necessary for driving low-sensitivity high-fidelity headphones.

[0033] See also Figure 1 , Figure 1 The headphone amplifier circuit 10 of the present embodiment includes an input control module 100 , a negative feedback module 110 , a voltage amplifier module 120 , a current amplifier module 130 , and a power supply module 140 .

[0034] In this embodiment, the input control module 100 is used to receive an audio signal transmitted from an audio device, the voltage amplification module 120 is used to perform voltage amplification on the audio signal transmitted from the input control module 100, and the current amplification module 130 is used to perform current amplification on the audio signal transmitted from the input control module 100, and finally output the amplified audio signal. The power supply module 140 provides power to the voltage amplification module 120 and the current amplification module 130, and the negative feedback module 110 is used to improve the stability and linearity of the circuit.

[0035] See also Figure 2 , Figure 2 The circuit diagram of a headphone amplifier circuit provided in this embodiment is as follows: the power supply module 140 is connected to the voltage amplifier module 120 and the current amplifier module 130 respectively to supply power to the voltage amplifier module 120 and the current amplifier module 130; the input control module 100 is connected to the current amplifier module 130 via the voltage amplifier module 120, so that the audio signal transmitted by the input control module 100 is first voltage-amplified and then current-amplified. The negative feedback module 110 is connected to the output end of the current amplifier module 130 and the input end of the voltage amplifier module 120 respectively, and the stability of the circuit is provided by the negative feedback module 110.

[0036] Further, please see again Figure 2 The input control module 100 includes a first capacitor C1 and a volume controller R1. In this embodiment, the first capacitor C1 can be an input coupling capacitor. The input coupling capacitor is used to ensure that the signal has a suitable impedance before entering the headphone amplifier circuit 10, and can remove any unnecessary DC components to protect the headphone amplifier circuit 10 from damage. At the same time, the value of the input coupling capacitor can affect the frequency response of the headphone amplifier circuit 10 to ensure the clarity and purity of the audio signal.

[0037] The first capacitor C1 is connected in series with the volume controller R1; the volume controller R1 is used to control the volume of the audio signal, and the volume controller R1 includes a first end, a second end and a control end, the first capacitor C1 is connected to the first end of the volume controller R1, the second end of the volume controller R1 is grounded, and the control end of the volume controller R1 is connected to the input end of the voltage amplification module 120. In this embodiment, the volume controller R1 can be a variable resistor, the resistance of the variable resistor is connected in series with the first capacitor C1, the sliding end of the variable resistor (that is, the control end of the volume controller) is connected to the input end of the voltage amplification module 120, and the current passing through the variable resistor is adjusted by moving the sliding end of the variable resistor, thereby controlling the audio signal received by the voltage amplification module 120.

[0038] Therefore, the input control module 100 ensures that the audio signal has a suitable impedance before entering the headphone amplifier circuit 10, thereby reducing signal loss and distortion. At the same time, the strength of the audio signal can be adjusted through the input control module 100 without affecting the performance of the headphone amplifier circuit 10.

[0039] Further, please see again Figure 2 , the negative feedback module 110 includes a second resistor R2 and a third resistor R3, the second resistor R2 and the third resistor R3 are connected in series; one end of the second resistor R2 and the third resistor R3 are grounded after being connected in series, and the other end of the second resistor R2 and the third resistor R3 are connected to the output end of the current amplifier module 130 after being connected in series; the input end of the voltage amplifier module 120 is connected between the second resistor R2 and the third resistor R3. In the above connection mode, the negative feedback module 110 reintroduces a part of the audio signal output by the headphone amplifier circuit 10 into the input end of the voltage amplifier module 120 in the form of opposite phase, significantly improving the performance of the voltage amplifier module 120 and the current amplifier module 130, including reducing distortion, improving stability and linearity, etc. At the same time, the negative feedback module 110 helps to expand the frequency response range of the headphone amplifier circuit 10.

[0040] It is worth noting that, in this embodiment, the second resistor R2 is connected to the output end of the current amplification module 130, and the other end is connected to the input end of the voltage amplification module 120, and is used to control the negative feedback amount of the voltage amplification module 120 and the current amplification module 130, thereby affecting their gain and bandwidth, so as to achieve the best performance of the entire headphone amplifier circuit 10. In addition, the second resistor R2 and the third resistor R3 can set the amplification factor, and the specific values ​​of the second resistor R2 and the third resistor R3 are not specifically limited here, but the values ​​of the second resistor R2 and the third resistor R3 need to be accurately calculated and selected according to actual circuit parameters and performance requirements.

[0041] Therefore, the negative feedback module 110 is connected to the output end of the current amplification module 130 and the input end of the voltage amplification module 120 to form a closed-loop control system. This connection method allows the amplifier to provide stable gain and improve the overall performance of the headphone amplifier circuit 10 while maintaining high sound quality.

[0042] Further, please see again Figure 2 The voltage amplification module 120 includes a voltage operational amplifier IC1, which is used to amplify the voltage signal, including a non-inverting input terminal, an inverting input terminal and an output terminal. The non-inverting input terminal is connected to the control terminal of the volume controller R1, allowing the user to adjust the volume through the control terminal of the volume controller R1; the inverting input terminal is connected between the second resistor R2 and the third resistor R3, and uses the voltage division principle and negative feedback mechanism to achieve stable gain control, improve frequency response and improve overall circuit performance; the output terminal of the voltage operational amplifier IC1 is connected to the current amplification module 130, and the audio signal amplified by the voltage operational amplifier IC1 is output to the current amplification module 130.

[0043] It is worth noting that, in this embodiment, the selection of the voltage operational amplifier IC1 in the voltage amplification module 120 is not specifically limited, but needs to be selected according to actual circuit parameters and performance requirements.

[0044] Therefore, the voltage amplification module 120 provides high-gain voltage amplification and achieves low distortion, high stability and wide-band response through negative feedback.

[0045] Furthermore, high-fidelity headphones, because their design goal is to provide sound quality as close to studio quality as possible, usually have higher impedance and lower sensitivity, which means that higher current drive is required. Figure 2In the headphone amplifier circuit 10, the current amplifier module 130 is a key component for achieving high-performance audio output. The current amplifier module 130 includes a current operational amplifier IC2. The current operational amplifier IC2 includes an input end and an output end. The input end of the current operational amplifier IC2 is connected to the output end of the voltage operational amplifier IC1, and receives the audio signal transmitted by the voltage amplifier module 120 and amplified by the voltage operational amplifier IC1. The current operational amplifier IC2 further converts and amplifies the voltage signal amplified by the voltage operational amplifier IC1 into a current signal; the output end of the current operational amplifier IC2 is used to drive the audio signal output to the headphone via the headphone amplifier circuit 10.

[0046] It is worth noting that, in this embodiment, the selection of the current operational amplifier IC2 in the current amplification module 130 is not specifically limited, but needs to be selected according to actual circuit parameters and performance requirements.

[0047] Therefore, the current amplification module 130 provides sufficient current driving force in the headphone amplifier circuit 10 to achieve clear, dynamic and distortion-free audio output; in addition, the staged amplification design in which the audio signal first passes through the voltage amplification module 120 and then through the current amplification module 130 enables the headphone amplifier circuit 10 to manage the signal amplification process more effectively, ensuring that the signal can maintain the purity and accuracy of the sound quality while being amplified, while meeting the current requirements of high-fidelity headphones.

[0048] Further, please see again Figure 2 , the power module 140 includes a first voltage output terminal and a second voltage output terminal; the voltage output by the first voltage output terminal is greater than the voltage output by the second voltage output terminal.

[0049] The first voltage output end is connected to the positive electrodes of the voltage amplification module 120 and the current amplification module 130 respectively, and the second voltage output end is connected to the negative electrodes of the voltage amplification module 120 and the current amplification module 130 respectively.

[0050] In this embodiment, the positive electrodes of the voltage amplification module 120 and the current amplification module 130 are the positive power pins of the voltage operational amplifier IC1 and the current operational amplifier IC2, and the negative electrodes of the voltage amplification module 120 and the current amplification module 130 are the negative power pins of the voltage operational amplifier IC1 and the current operational amplifier IC2; the headphone amplifier circuit 10 adopts a bipolar power supply, the first voltage output terminal is a positive power supply, and the second voltage output terminal is a negative power supply. The bipolar power supply can be a regulated power supply to provide precise positive and negative voltages to achieve stable output of the amplifier signal.

[0051] Therefore, the power module 140 can provide stable and sufficient power while ensuring the normal operation of each circuit part and optimizing the sound quality performance.

[0052] Further, please see again Figure 2 , the current amplification module 130 further includes a fourth resistor R4, the current operational amplifier IC2 further includes a bias terminal, one end of the fourth resistor R4 is connected to the bias terminal of the current operational amplifier IC2, and the other end of the fourth resistor R4 is connected to the second voltage output terminal of the power module 140, the fourth resistor R4 is used to adjust the bandwidth of the current operational amplifier IC2, and the value of the fourth resistor R4 affects the size of the bias current, thereby affecting the performance of the entire circuit;

[0053] It is worth noting that, in this embodiment, the value of the fourth resistor R4 is not specifically limited, but needs to be determined according to actual circuit parameters and performance requirements.

[0054] Further, please see again Figure 2 The power module 140 further includes a first decoupling capacitor C2 and a second decoupling capacitor C3. The first voltage output terminal is grounded through the first decoupling capacitor C2, and the second voltage output terminal is grounded through the second decoupling capacitor C3.

[0055] In this embodiment, the first decoupling capacitor C2 and the second decoupling capacitor C3 are used to filter power supply noise, stabilize the power supply voltage, and provide transient current to ensure that the voltage operational amplifier and the current operational amplifier work stably and improve the sound quality.

[0056] Based on the same concept, the present application also provides an earphone volume control device 20, see Figure 3 The headphone volume control device 20 includes an independently arranged left channel headphone amplifier circuit 200 and a right channel headphone amplifier circuit 210, wherein the left channel headphone amplifier circuit 200 and the right channel headphone amplifier circuit 210 are implemented by using any one of the headphone amplifier circuits 10 provided in the present application.

[0057] In this embodiment, setting the headphone volume control device 20 to dual channels (ie, left channel and right channel) can achieve stereo audio reproduction, providing a more natural, realistic and fascinating auditory experience.

[0058] Furthermore, the headphone volume control device 20 also includes an headphone socket 220 arranged at the output end of the current amplification module in the left channel headphone amplifier circuit 200 and the right channel headphone amplifier circuit 210, wherein the signal amplified by the left channel headphone amplifier circuit 200 and the right channel headphone amplifier circuit 210 is output to the headphone through the headphone socket 220.

[0059] It is worth noting that the output ends of the current amplification modules in the left channel headphone amplifier circuit 200 and the right channel amplifier circuit 210 are in contact with the conductive contacts inside the headphone socket 220, so that the audio signal is transmitted to the headphone. The type and specific size of the headphone socket 220 are not specifically limited, but the headphone socket 220 should match the headphone.

[0060] In summary, the embodiment of the present application provides a headphone amplifier circuit 10 and a headphone volume control device 20, wherein the headphone amplifier circuit 10 includes an input control module 100, a negative feedback module 110, a voltage amplifier module 120, a current amplifier module 130 and a power module 140; the power module 140 is connected to the voltage amplifier module 120 and the current amplifier module 130 to supply power to the voltage amplifier module 120 and the current amplifier module 130; the input control module 100 is connected to the current amplifier module 130 via the voltage amplifier module 120, and the negative feedback module 110 is respectively connected to the output end of the current amplifier module 130 and the input end of the voltage amplifier module 120. Thus, through the above structure, the headphone amplifier circuit is connected between an audio device (such as a smart phone, an MP3 player) and a headphone, providing sufficient current and voltage for the headphone, ensuring that the audio signal is transmitted to the headphone with the characteristics of large current, wide frequency response and high conversion rate after amplification, thereby ensuring that the headphone can work normally and exert its best sound quality performance.

[0061] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A headphone amplifier circuit, characterized in that: The headphone amplifier circuit includes an input control module, a negative feedback module, a voltage amplifier module, a current amplifier module and a power supply module; The power supply module is connected to the voltage amplification module and the current amplification module to supply power to the voltage amplification module and the current amplification module; The input control module is connected to the current amplification module via the voltage amplification module, and the negative feedback module is connected to the output end of the current amplification module and the input end of the voltage amplification module respectively.

2. The headphone amplifier circuit according to claim 1, characterized in that: The input control module includes a first capacitor and a volume controller; The first capacitor is connected in series with the volume controller; The volume controller includes a first end, a second end and a control end. The first capacitor is connected to the first end of the volume controller. The second end of the volume controller is grounded. The control end of the volume controller is connected to the input end of the voltage amplification module.

3. The headphone amplifier circuit according to claim 2, characterized in that: The negative feedback module includes a second resistor and a third resistor, and the second resistor and the third resistor are connected in series; One end of the second resistor and the third resistor connected in series is grounded, and the other end of the second resistor and the third resistor connected in series is connected to the output end of the current amplification module; The input end of the voltage amplification module is connected between the second resistor and the third resistor.

4. The headphone amplifier circuit according to claim 3, characterized in that: The voltage amplification module includes a voltage operational amplifier, and the voltage operational amplifier includes a non-inverting input terminal, an inverting input terminal and an output terminal, the non-inverting input terminal is connected to the control terminal of the volume controller, and the inverting input terminal is connected between the second resistor and the third resistor; The output end of the voltage operational amplifier is connected to the current amplification module.

5. The headphone amplifier circuit according to claim 4, characterized in that: The current amplification module includes a current operational amplifier, which includes an input end and an output end. The input end of the current operational amplifier is connected to the output end of the voltage operational amplifier, and the output end of the current operational amplifier is used for driving signal output.

6. The headphone amplifier circuit according to claim 5, characterized in that: The power supply module comprises a first voltage output terminal and a second voltage output terminal; the voltage output by the first voltage output terminal is greater than the voltage output by the second voltage output terminal; The first voltage output end is connected to the positive poles of the voltage amplification module and the current amplification module respectively, and the second voltage output end is connected to the negative poles of the voltage amplification module and the current amplification module respectively.

7. The headphone amplifier circuit according to claim 6, characterized in that: The current amplification module also includes a fourth resistor, and the current operational amplifier also includes a bias end. One end of the fourth resistor is connected to the bias end of the current operational amplifier, and the other end of the fourth resistor is connected to the second voltage output end of the power supply module. The fourth resistor is used to adjust the bandwidth of the current operational amplifier.

8. The headphone amplifier circuit according to claim 7, characterized in that: The power supply module further includes a first decoupling capacitor and a second decoupling capacitor. The first voltage output terminal is grounded through the first decoupling capacitor, and the second voltage output terminal is grounded through the second decoupling capacitor.

9. An earphone volume control device, characterized in that: The headphone volume control device comprises an independently arranged left channel headphone amplifier circuit and a right channel headphone amplifier circuit, wherein the left channel headphone amplifier circuit and the right channel headphone amplifier circuit are implemented by the headphone amplifier circuit according to any one of claims 1-8.

10. The headphone volume control device according to claim 9, characterized in that: The headphone volume control device also includes an headphone socket arranged at the output end of the current amplification module in the left channel headphone amplifier circuit and the right channel headphone amplifier circuit, and the signal amplified by the left channel headphone amplifier circuit and the right channel headphone amplifier circuit is output to the headphone through the headphone socket.

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