Amplitude limiting circuit and earphone

Abstract

The utility model discloses an amplitude limiting circuit and an earphone. The amplitude limiting circuit comprises a first signal branch and a second signal branch. The power input end is connected with the first signal branch, and the grounding end is connected with the second signal branch; the first amplitude limiting module comprises a first resistor and a first diode module, the first end of the first diode module is connected with the first signal branch, the second end of the first diode module is connected with the second signal branch, and the first resistor is connected between the power input end and the first diode module; the second amplitude limiting module comprises a second resistor and a second diode module, the first end of the second diode module is connected with the second signal branch, the second end of the second diode module is connected with the first signal branch, and the second resistor is connected between the grounding end and the second diode module. According to the utility model, the self-excitation noise can be effectively suppressed, and the user experience is improved.

Description

Technical Field

[0001] This utility model relates to the field of signal limiting technology, and in particular to a limiting circuit and an earphone. Background Technology

[0002] With the rapid development of the economy, noise problems in people's living environment have become increasingly prominent. Most headphones on the market have noise reduction functions. The main technology used is to use the method of MIC picking up noise and canceling it out. However, when the noise reduction effect is too deep and the amplitude of MIC picking up noise is too large, self-excited oscillation will be formed, which will lead to a decline in the user experience. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a limiting circuit and headphones that can effectively suppress self-oscillating noise and improve the user experience.

[0004] This utility model also proposes an earphone with the above-mentioned limiting circuit.

[0005] The limiting circuit according to a first aspect embodiment of the present invention includes:

[0006] First signal branch;

[0007] Second signal branch;

[0008] An input power module, comprising a power input terminal and a ground terminal, wherein the power input terminal is connected to the first signal branch and the ground terminal is connected to the second signal branch;

[0009] The first limiting module includes a first resistor and a first diode module. The first end of the first diode module is connected to the first signal branch, the second end of the first diode module is connected to the second signal branch, and the first resistor is connected between the power input terminal and the first diode module.

[0010] The second limiting module includes a second resistor and a second diode module. The first end of the second diode module is connected to the second signal branch, the second end of the second diode module is connected to the first signal branch, and the second resistor is connected between the ground terminal and the second diode module.

[0011] Wherein, the phase of the signal input to the first signal branch is the same as the phase of the signal to be processed, and the phase of the signal input to the second signal branch is opposite to the phase of the signal to be processed.

[0012] The limiting circuit according to the embodiments of this utility model has at least the following beneficial effects: The first diode module and the second diode module can limit the signals input to the first signal branch and the second signal branch, thereby suppressing self-oscillating noise and improving the user experience. Furthermore, by setting a first resistor on the first signal branch and a second resistor on the second signal branch, the circuit damage caused by the rapid increase in current when the first and second diode modules are turned on can be avoided. In addition, the differential circuit formed by the first and second signal branches cancels out the common-mode signals in the two signals, thereby improving the signal's anti-interference capability.

[0013] According to some embodiments of the present invention, the first diode module includes a first Schottky diode and a second Schottky diode. The negative terminal of the first Schottky diode is connected to the first signal branch, the positive terminal of the first Schottky diode is connected to the negative terminal of the second Schottky diode, and the positive terminal of the second Schottky diode is connected to the second signal branch.

[0014] According to some embodiments of the present invention, the second diode module includes a third Schottky diode and a fourth Schottky diode. The positive terminal of the third Schottky diode is connected to the first signal branch, the negative terminal of the third Schottky diode is connected to the positive terminal of the fourth Schottky diode, and the negative terminal of the fourth Schottky diode is connected to the second signal branch.

[0015] According to some embodiments of the present invention, the limiting circuit further includes a first capacitor, which is connected between the power input terminal and the first resistor.

[0016] According to some embodiments of the present invention, the limiting circuit further includes a second capacitor, which is connected between the ground terminal and the second resistor.

[0017] According to some embodiments of the present invention, the limiting circuit includes a third resistor and a third capacitor. The first end of the third resistor is connected to the power input terminal, the second end of the third resistor is connected to the first end of the third capacitor and the first signal branch, and the second end of the third capacitor is grounded.

[0018] According to some embodiments of the present invention, the limiting circuit further includes a fourth resistor, the first end of which is connected to the connection point of the third resistor and the third capacitor, and the second end of which is connected to the first signal branch.

[0019] According to some embodiments of the present invention, the limiting circuit further includes a fifth resistor, the first end of which is connected to the second signal branch, and the second end of which is grounded.

[0020] According to some embodiments of the present invention, the limiting circuit further includes a capacitor module, which includes a fourth capacitor and a fifth capacitor. The first terminal of the fourth capacitor is connected to the connection point of the first resistor and the first diode module, and the second terminal of the fourth capacitor is grounded. The first terminal of the fifth capacitor is connected to the connection point of the second resistor and the first diode module, and the second terminal of the fifth capacitor is grounded.

[0021] The earphone according to a second aspect embodiment of the present invention includes the limiting circuit of the first aspect.

[0022] The earphones according to embodiments of this utility model have at least the following beneficial effects: The first diode module and the second diode module can limit the amplitude of the signals input to the first signal branch and the second signal branch, thereby suppressing self-oscillating noise and improving the user experience. Furthermore, by setting a first resistor on the first signal branch and a second resistor on the second signal branch, the circuit damage caused by the rapid increase in current when the first and second diode modules are turned on can be avoided. In addition, the differential circuit formed by the first and second signal branches cancels out the common-mode signals in the two signals, thereby improving the signal's anti-interference capability.

[0023] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0025] Figure 1 This is a circuit diagram of the limiting circuit according to an embodiment of the present invention. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0028] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0029] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0030] With the rapid development of the economy, noise problems in people's living environment have become increasingly prominent. Most headphones on the market have noise reduction functions. The main technology used is to use the method of MIC picking up noise and canceling it out. However, when the noise reduction effect is too deep and the amplitude of MIC picking up noise is too large, self-excited oscillation will be formed, resulting in a decline in the user experience.

[0031] Based on this, this utility model embodiment provides a limiting circuit and headphones. The first diode module and the second diode module can limit the signals input to the first signal branch and the second signal branch, thereby suppressing self-oscillating noise and improving the user experience. Furthermore, by setting a first resistor on the first signal branch and a second resistor on the second signal branch, the circuit damage caused by the rapid increase in current when the first and second diode modules are turned on can be avoided. In addition, the differential circuit formed by the first and second signal branches cancels out the common-mode signals in the two signals, thereby improving the signal's anti-interference capability.

[0032] Firstly, referring to Figure 1 , Figure 1 This is a circuit diagram of the limiting circuit according to an embodiment of the present invention.

[0033] It is understood that the limiting circuit includes a first signal branch, a second signal branch, an input power supply module, a first limiting module, and a second limiting module. The first limiting module includes a first resistor R1 and a first diode module U1, the second limiting module includes a second resistor R2 and a second diode module U2, and the input power supply module includes a power input terminal V_ANC_MIC and a ground terminal GND.

[0034] Specifically, the first terminal of the first diode module U1 is connected to the first signal branch, the second terminal of the first diode module U1 is connected to the second signal branch, and the first resistor R1 is connected between the power input terminal V_ANC_MIC and the first diode module U1; the first terminal of the second diode module U2 is connected to the second signal branch, the second terminal of the second diode module U2 is connected to the first signal branch, and the second resistor R2 is connected between the ground terminal GND and the second diode module U2.

[0035] It is understandable that when the signal to be processed is input from the first input terminal FB+ of the first signal branch and the second input terminal FB- of the second signal branch, after being limited by the first diode module U1 and the second diode module U2, it is output from the first output terminal MIC_P of the first signal branch and the second output terminal MIC_N of the second signal branch. When the first diode module U1 and the second diode module U2 are turned on, the voltage will be limited to a certain range, thereby achieving signal limiting.

[0036] It should be noted that the phase of the signal input to the first signal branch is the same as the phase of the signal to be processed, while the phase of the signal input to the second signal branch is opposite to the phase of the signal to be processed. By inputting signals with opposite phases, the common-mode signals in the two signals will cancel each other out, which can improve the anti-interference capability of the signal.

[0037] It is understood that the first diode module U1 includes a first Schottky diode D1 and a second Schottky diode D2. The negative terminal of the first Schottky diode D1 is connected to the first signal branch, the positive terminal of the first Schottky diode D1 is connected to the negative terminal of the second Schottky diode D2, and the positive terminal of the second Schottky diode D2 is connected to the second signal branch. By connecting the first Schottky diode D1 and the second Schottky diode D2 in series, the forward conduction voltage of the first diode module U1 can be increased.

[0038] Understandably, the second diode module U2 includes a third Schottky diode D3 and a fourth Schottky diode D4. The positive terminal of the third Schottky diode D3 is connected to the first signal branch, the negative terminal of the third Schottky diode D3 is connected to the positive terminal of the fourth Schottky diode D4, and the negative terminal of the fourth Schottky diode D4 is connected to the second signal branch. By connecting the third Schottky diode D3 and the fourth Schottky diode D4 in series, the forward conduction voltage of the second diode module U2 can be increased.

[0039] It is understood that the limiting circuit also includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 is located on the first signal branch, with its first terminal connected to the first terminal of the first resistor R1, and its second terminal connected to the connection point between the power input terminal V_ANC_MIC and the first input terminal FB+ of the first signal branch. The second capacitor C2 is located on the second signal branch, with its first terminal connected to the first terminal of the second resistor R2, and its second terminal connected to the connection point between the ground terminal GND and the second input terminal FB- of the second signal branch. By using the first capacitor C1 on the first signal branch and the second capacitor C2 on the second signal branch, the DC bias voltage can be isolated.

[0040] It should be noted that the limiting circuit also includes a third resistor R3 and a third capacitor C3. The first terminal of the third resistor R3 is connected to the power input terminal V_ANC_MIC, and the second terminal of the third resistor R3 is connected to both the first terminal of the third capacitor C3 and the first signal branch. The second terminal of the third capacitor C3 is grounded. The filtering branch formed by the third resistor R3 and the third capacitor C3 can filter the voltage input to the power input terminal V_ANC_MIC.

[0041] It should be noted that the limiting circuit also includes a fourth resistor R4 and a fifth resistor R5. The first end of the fourth resistor R4 is connected to the connection point of the third resistor R3 and the third capacitor C3. The second end of the fourth resistor R4 is connected to the first signal branch. The first end of the fifth resistor R5 is connected to the second signal branch. The second end of the fifth resistor R5 is grounded.

[0042] It is understandable that the limiting circuit also includes a capacitor module, which includes a fourth capacitor C4 and a fifth capacitor C5. The first end of the fourth capacitor C4 is connected to the connection point of the first resistor R1 and the first diode module U1, and the second end of the fourth capacitor C4 is grounded. The first end of the fifth capacitor C5 is connected to the connection point of the second resistor R2 and the first diode module U1, and the second end of the fifth capacitor C5 is grounded.

[0043] Secondly, this utility model embodiment provides an earphone that uses a first diode module U1 and a second diode module U2 to limit the signals input to the first and second signal branches, thereby suppressing self-oscillating noise and improving the user experience. Furthermore, by setting a first resistor R1 on the first signal branch and a second resistor R2 on the second signal branch, circuit damage caused by a rapid increase in current when the first and second diode modules U1 and U2 are turned on can be avoided. In addition, the differential circuit formed by the first and second signal branches cancels out the common-mode signals in the two signals, thereby improving the signal's anti-interference capability.

[0044] It should be noted that in some embodiments, the headphones are noise-canceling headphones with noise reduction function. After the noise-canceling headphones pick up the noise signal, they can input it into the limiting circuit. The limiting circuit limits the noise signal to avoid self-excited oscillation due to excessive noise amplitude.

[0045] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A limiting circuit, characterized in that, include: First signal branch; Second signal branch; An input power module, comprising a power input terminal and a ground terminal, wherein the power input terminal is connected to the first signal branch and the ground terminal is connected to the second signal branch; The first limiting module includes a first resistor and a first diode module. The first end of the first diode module is connected to the first signal branch, the second end of the first diode module is connected to the second signal branch, and the first resistor is connected between the power input terminal and the first diode module. The second limiting module includes a second resistor and a second diode module. The first end of the second diode module is connected to the second signal branch, the second end of the second diode module is connected to the first signal branch, and the second resistor is connected between the ground terminal and the second diode module. Wherein, the phase of the signal input to the first signal branch is the same as the phase of the signal to be processed, and the phase of the signal input to the second signal branch is opposite to the phase of the signal to be processed.

2. The limiting circuit according to claim 1, characterized in that, The first diode module includes a first Schottky diode and a second Schottky diode. The negative terminal of the first Schottky diode is connected to the first signal branch, the positive terminal of the first Schottky diode is connected to the negative terminal of the second Schottky diode, and the positive terminal of the second Schottky diode is connected to the second signal branch.

3. The limiting circuit according to claim 1, characterized in that, The second diode module includes a third Schottky diode and a fourth Schottky diode. The positive terminal of the third Schottky diode is connected to the first signal branch, the negative terminal of the third Schottky diode is connected to the positive terminal of the fourth Schottky diode, and the negative terminal of the fourth Schottky diode is connected to the second signal branch.

4. The limiting circuit according to claim 1, characterized in that, The limiting circuit also includes a first capacitor, which is connected between the power input terminal and the first resistor.

5. The limiting circuit according to claim 1, characterized in that, The limiting circuit also includes a second capacitor, which is connected between the ground terminal and the second resistor.

6. The limiting circuit according to claim 1, characterized in that, The limiting circuit includes a third resistor and a third capacitor. The first end of the third resistor is connected to the power input terminal, the second end of the third resistor is connected to the first end of the third capacitor and the first signal branch, and the second end of the third capacitor is grounded.

7. The limiting circuit according to claim 6, characterized in that, The limiting circuit further includes a fourth resistor, the first end of which is connected to the connection point of the third resistor and the third capacitor, and the second end of which is connected to the first signal branch.

8. The limiting circuit according to claim 1, characterized in that, The limiting circuit also includes a fifth resistor, the first end of which is connected to the second signal branch, and the second end of which is grounded.

9. The limiting circuit according to claim 1, characterized in that, The limiting circuit also includes a capacitor module, which includes a fourth capacitor and a fifth capacitor. The first terminal of the fourth capacitor is connected to the connection point of the first resistor and the first diode module, and the second terminal of the fourth capacitor is grounded. The first terminal of the fifth capacitor is connected to the connection point of the second resistor and the first diode module, and the second terminal of the fifth capacitor is grounded.

10. An earphone, characterized in that, Includes the limiting circuit as described in any one of claims 1 to 9.

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