阅读说明：本技术 一种耳机输出阻抗自适应系统及方法 (Earphone output impedance self-adaption system and method ) 是由 曹振雷 马翼平 许召辉 王阳 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种耳机输出阻抗自适应系统,包括：运算处理单元,用于采集输入、输出音频幅值,以及根据输入、输出音频幅值计算对应阻抗；第一阻抗调整单元,与音频播放设备和运算处理单元连接,并用于根据运算处理单元的对应计算结果调整阻抗；第二阻抗调整单元,与耳机和运算处理单元连接,并用于根据运算处理单元的对应计算结果调整阻抗；音频调整单元,与运算处理单元、第一阻抗调整单元和第二阻抗调整单元连接,并用于根据运算处理单元的音量调整信号调整输出音频信号；供电单元,与运算处理单元和音频调整单元连接并用于供电。本发明改善了音频信号通路上的整体转换效率,从而获取了最佳的耳机输出效果,完成动态音量自适应。(The invention discloses an earphone output impedance self-adapting system, which comprises: the operation processing unit is used for acquiring input and output audio amplitudes and calculating corresponding impedance according to the input and output audio amplitudes; the first impedance adjusting unit is connected with the audio playing device and the operation processing unit and used for adjusting the impedance according to the corresponding calculation result of the operation processing unit; the second impedance adjusting unit is connected with the earphone and the operation processing unit and used for adjusting the impedance according to the corresponding calculation result of the operation processing unit; the audio adjusting unit is connected with the operation processing unit, the first impedance adjusting unit and the second impedance adjusting unit and is used for adjusting and outputting an audio signal according to the volume adjusting signal of the operation processing unit; and the power supply unit is connected with the arithmetic processing unit and the audio frequency adjusting unit and is used for supplying power. The invention improves the overall conversion efficiency on the audio signal path, thereby obtaining the optimal earphone output effect and completing the dynamic volume self-adaptation.)

1. An earphone output impedance adaptive system for connection between an audio playback device and an earphone, comprising:

the operation processing unit is used for acquiring input and output audio amplitudes and calculating corresponding impedance according to the input and output audio amplitudes;

the first impedance adjusting unit is connected with the audio playing device and the operation processing unit and used for adjusting impedance according to the corresponding calculation result of the operation processing unit;

the second impedance adjusting unit is connected with the earphone and the operation processing unit and used for adjusting impedance according to a corresponding calculation result of the operation processing unit;

the audio adjusting unit is connected with the operation processing unit, the first impedance adjusting unit and the second impedance adjusting unit and is used for adjusting and outputting an audio signal according to a volume adjusting signal of the operation processing unit;

and the power supply unit is connected with the operation processing unit and the audio adjusting unit and is used for supplying power.

2. The headphone output impedance adaptation system of claim 1, further comprising:

and the clock unit is connected with the operation processing unit and used for providing clock signals of the operation processing unit and the audio adjusting unit circuit.

3. The system of claim 1, wherein the first impedance adjustment unit and the second impedance adjustment unit each comprise an adjustable resistor, and the arithmetic processing unit is connected to the adjustable resistor through an adjustable voltage pin.

4. The system of claim 1, wherein the output voltage of the power supply unit is 4.5V-40V.

5. The headphone output impedance adaptation system of claim 1, further comprising a buck unit comprising a DC/DC and LDO hybrid circuit.

6. The headphone output impedance adaptive system according to claim 1, further comprising a protection unit, the protection unit comprising an under-voltage protection circuit.

7. A headphone output impedance adaptive method, characterized in that the headphone output impedance adaptive system according to any one of claims 1-6 is adopted, and comprises the following steps:

s1 when the system is started, the arithmetic processing unit controls the first impedance adjustment unit, the second impedance adjustment unit, and the audio adjustment unit to adjust to initial positions;

s2, the operation processing unit controls the audio adjusting unit to output a reference signal, collects the input and output audio amplitude, and adjusts the impedance of the first impedance adjusting unit and the second impedance adjusting unit according to the input and output audio amplitude and the earphone impedance;

s3, the arithmetic processing unit cancels the reference signal and outputs a volume adjusting signal to the audio adjusting unit according to the input audio amplitude;

s4 the audio adjusting unit adjusts the output audio signal according to the adjusting signal.

Technical Field

The invention relates to the technical field of earphones, in particular to an earphone output impedance self-adaption system and method.

Background

The earphone is used for being connected with the audio playing device for use so as to receive audio information with the earphone. Under the condition that the power of the equipment is not changed, the actual output power of the earphone is mainly determined by the impedance (external resistance) of the earphone and the internal resistance of the equipment, and theoretical calculation shows that when the external resistance is equal to the internal resistance, the earphone can obtain the maximum output power.

At present, earphones in the market generally have an impedance of 32 Ω, and are suitable for most electronic devices, but some electronic devices have large-span impedance ranges of 150 Ω, 300 Ω, 600 Ω, 20000 Ω and the like, and generally adopt customized earphone matching for the type of electronic devices, so that the universality and maintainability of the devices are hindered to a certain extent. Therefore, it is necessary to provide a further solution to the above problems.

Disclosure of Invention

The invention aims to provide an earphone output impedance self-adapting system and method to overcome the defects in the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows:

an earphone output impedance adaptive system for connection between an audio playback device and an earphone, comprising:

the operation processing unit is used for acquiring input and output audio amplitudes and calculating corresponding impedance according to the input and output audio amplitudes;

the first impedance adjusting unit is connected with the audio playing device and the operation processing unit and used for adjusting impedance according to the corresponding calculation result of the operation processing unit;

the second impedance adjusting unit is connected with the earphone and the operation processing unit and used for adjusting impedance according to a corresponding calculation result of the operation processing unit;

the audio adjusting unit is connected with the operation processing unit, the first impedance adjusting unit and the second impedance adjusting unit and is used for adjusting and outputting an audio signal according to a volume adjusting signal of the operation processing unit;

and the power supply unit is connected with the operation processing unit and the audio adjusting unit and is used for supplying power.

In a preferred embodiment of the present invention, the method further comprises:

and the clock unit is connected with the operation processing unit and used for providing clock signals of the operation processing unit and the audio adjusting unit circuit.

In a preferred embodiment of the present invention, the first impedance adjusting unit and the second impedance adjusting unit each include an adjustable resistor, and the arithmetic processing unit is connected to the first impedance adjusting unit and the second impedance adjusting unit through an adjustable voltage pin.

Audio adjusting unit in a preferred embodiment of the present invention, the output voltage of the power supply unit is 4.5V-40V.

In a preferred embodiment of the present invention, the apparatus further comprises a step-down unit, wherein the step-down unit comprises a DC/DC and LDO hybrid circuit.

In a preferred embodiment of the present invention, the protection circuit further comprises a protection unit, and the protection unit comprises an under-voltage protection circuit.

The other technical scheme of the invention is as follows:

an earphone output impedance self-adapting method, which adopts any one of the earphone output impedance self-adapting systems and comprises the following steps:

s1 when the system is started, the arithmetic processing unit controls the first impedance adjustment unit, the second impedance adjustment unit, and the audio adjustment unit to adjust to initial positions;

s2, the operation processing unit controls the audio adjusting unit to output a reference signal, collects the input and output audio amplitude, and adjusts the impedance of the first impedance adjusting unit and the second impedance adjusting unit according to the input and output audio amplitude and the earphone impedance;

s3, the arithmetic processing unit cancels the reference signal and outputs a volume adjusting signal to the audio adjusting unit according to the input audio amplitude;

s4 the audio adjusting unit adjusts the output audio signal according to the adjusting signal.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the input and output signal levels are collected through the operation processing unit, the audio frequency adjusting unit, the first impedance adjusting unit and the second impedance adjusting unit, so that the impedance of the path is adjusted in multiple gears, the problem that a large-impedance earphone is driven by low power or a small-impedance earphone is driven by high power is solved, the overall conversion efficiency on the audio signal path is improved, the optimal earphone output effect is obtained, and the dynamic volume self-adaption is completed.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of the system of the present invention;

FIG. 2 is a circuit diagram of the present invention;

fig. 3 is a block diagram of signal processing in the present invention.

Wherein, 1, an arithmetic processing unit; 2. a first impedance adjustment unit; 3. a second impedance adjusting unit; 4. an audio adjusting unit; 5. a clock unit;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

As shown in fig. 1 and 2, an earphone output impedance adaptive system is used for connecting between an audio playing device and an earphone, and further, is arranged at the front end of an earphone loudspeaker. The system comprises an operation processing unit 1, a first impedance adjusting unit 2, a second impedance adjusting unit 3, an audio adjusting unit 4 and a power supply unit.

Specifically, the arithmetic processing unit 1 is configured to collect input and output audio amplitudes, and calculate corresponding impedances according to the input and output audio amplitudes. The first impedance adjusting unit 2 is connected to the audio playback device and the arithmetic processing unit 1, and is configured to adjust the impedance according to a corresponding calculation result of the arithmetic processing unit 1. The second impedance adjusting unit 3 is connected to the headphone and the arithmetic processing unit 1, and is configured to adjust the impedance according to a corresponding calculation result of the arithmetic processing unit 1. The audio adjusting unit 4 is connected to the arithmetic processing unit 1, the first impedance adjusting unit 2, and the second impedance adjusting unit 3, and is configured to adjust an output audio signal according to a volume adjustment signal of the arithmetic processing unit 1. The power supply unit is connected to the arithmetic processing unit 1 and the audio adjusting unit 4 and supplies power.

More specifically, the first impedance adjusting unit 2 and the second impedance adjusting unit 3 both include an adjustable resistor, and the arithmetic processing unit 1 is connected thereto through an adjustable voltage pin, respectively.

Preferably, the output voltage of the power supply unit is 4.5V-40V, in order to match in particular the current supply threshold of most military communication equipment.

The system also comprises a clock unit 5, wherein the clock unit 5 is connected with the operation processing unit 1 and is used for providing circuit clock signals of the operation processing unit 1 and the audio frequency adjusting unit 4.

The system also comprises a voltage reduction unit, wherein the voltage reduction unit comprises a DC/DC and LDO mixed circuit, the DC/DC can reduce the voltage conversion loss, and the LDO can enhance the ripple rejection. Furthermore, the system also comprises a protection unit, and the protection unit comprises an undervoltage protection circuit. When the external voltage input is too low, the power supply unit fails, so that the operation processing unit 1 and the audio adjusting unit 4 are closed, the system is protected, and the service life of the system is ensured.

After the system is configured at the front end of the earphone loudspeaker, when the earphone is connected with the audio playing equipment, the system can adjust the impedance of a channel according to the detected signal level value and preferentially selects the gear closest to the internal resistance of the audio playing equipment, so that the overall conversion efficiency of the audio signal channel is improved, and a user can obtain the best earphone output effect at the first time.

The application also discloses an earphone output impedance self-adapting method, which comprises the following steps when the system is adopted:

after the S1 system is started, the arithmetic processing unit 1 controls the first impedance adjusting unit 2, the second impedance adjusting unit 3, and the audio adjusting unit 4 to adjust to the initial positions;

the S2 arithmetic processing unit 1 controls the audio frequency adjusting unit 4 to output a reference signal, collects the input and output audio frequency amplitude, and adjusts the impedance of the first impedance adjusting unit 2 and the second impedance adjusting unit 3 according to the two and the earphone impedance;

s3, the arithmetic processing unit 1 cancels the reference signal and outputs the volume adjusting signal to the audio adjusting unit 4 according to the input audio amplitude;

s4 the audio adjusting unit 4 adjusts the output audio signal according to the adjustment signal.

More specifically, as shown in fig. 1 and fig. 2, after the system is powered on, the clock unit 5 provides the main clock signal of the circuits of the arithmetic processing unit 1 and the audio adjusting unit 4, the arithmetic processing unit 1 receives the start clock signal and then obtains the execution program through the on-chip data access subunit, the initialization of the system program is started, and the first impedance adjusting unit 2 and the second impedance adjusting unit 3 are adjusted to the initial positions.

Then, the arithmetic processing unit 1 completes the operation initialization configuration of the audio adjusting unit 4 through the communication bus, and adjusts the audio adjusting unit 4 to the initial position.

After the configuration is completed, the operation processing unit 1 controls the audio adjusting unit 4 to output a reference signal, and meanwhile, the operation processing unit 1 collects audio amplitude values at the audio output interface and the audio input interface and respectively performs impedance matching calculation according to the earphone impedance.

That is, as shown in fig. 3, when power is turned on, the CPU (SMT32F) of the arithmetic processing unit 1 controls the audio decoding chip (codec) in the audio adjusting unit 4 to output a reference signal, and at the same time, collects and detects signals at the interface. The acquired interface audio signal is compared and calculated through an ADC analog-to-digital conversion channel of the CPU, a corresponding impedance control signal is output according to the calculated audio amplitude, the impedance of an interface channel is compensated and matched, and the impedance control module stops impedance adjustment until the acquired audio amplitude meets the calculation requirement.

And finishing impedance adjustment through the calculated value, confirming the input and output impedance withdrawing pin reference signal, and finishing power-on initialization impedance matching. The arithmetic processing unit 1 outputs a volume adjustment signal to the audio adjustment unit 4 according to the actual situation, i.e. the dynamic input audio amplitude. The audio adjusting unit 4 completes the adjustment of the output audio signal according to the adjusting signal, and completes the dynamic volume self-adaptation.

In summary, the present invention collects the input and output signal levels through the operation processing unit, the audio adjusting unit, the first impedance adjusting unit and the second impedance adjusting unit, further performs multi-stage adjustment of the path impedance, solves the problem of driving a large-impedance earphone with low power or driving a small-impedance earphone with high power, improves the overall conversion efficiency on the audio signal path, and thus obtains the optimal earphone output effect and completes dynamic volume adaptation.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.