Power failure processing circuit, audio circuit and electronic equipment

Abstract

The utility model discloses a power failure processing circuit, an audio circuit and an electronic device. The power failure processing circuit comprises a detection circuit, a first voltage conversion circuit, a processing circuit and an audio amplification circuit. The input end of the detection circuit is connected with a first DC voltage, and the output end is connected with the detection end of the processing circuit. The power supply end of the processing circuit is connected with second direct-current voltage; the input end of the first voltage conversion circuit is connected with a first DC voltage, and the output end is connected with the power end of the processing circuit and the power end of the audio amplification circuit. The output end of the processing circuit is connected with the audio amplifying circuit; according to the utility model, after the first voltage conversion circuit reduces the first DC voltage, the second voltage is output to the power supply end of the processing circuit; when the second direct-current voltage is not enough to support operation of the processing circuit during rapid power failure, the second voltage provides working voltage for the processing circuit, so that the processing circuit detects the power failure condition through the detection circuit and controls the audio amplification circuit to reduce the output voltage of the audio amplification circuit, and pop sound is prevented from being generated.

Description

TECHNICAL FIELD

[0001] The utility model relates to audio processing technical field, especially involve a power -down processing circuit, audio frequency circuit and electronic equipment. BACKGROUND

[0002] The power board is used to supply power for the processor in the audio frequency circuit, when the power board appears the fault or the output voltage of power board power -down, because the working voltage of processor is lower, when the output voltage of power board power -down, the supply voltage of processor will be lower than the minimum voltage of processor operation in short time, lead to the processor stop working, cannot detect the output voltage of power board power -down, cannot carry out the fade -in fade -out processing of sound to the audio amplifier circuit until there is no sound, lead to produce pop sound. SUMMARY

[0003] The utility model discloses a power -down processing circuit, audio frequency circuit and electronic equipment, and aims at solving the problem of power -down too fast, lead to the processor stop working, produce pop sound.

[0004] In order to realize the above -mentioned purpose, the power -down processing circuit provided by the utility model includes:

[0005] Detection circuit, first voltage conversion circuit, processing circuit and audio amplifier circuit;

[0006] The input end of detection circuit is connected with first direct current voltage, and the output end is connected with the detection end of processing circuit;The power end of processing circuit is connected with second direct current voltage;The input end of first voltage conversion circuit is connected with first direct current voltage, and the output end is connected with the power end of processing circuit and the power end of audio amplifier circuit;The output end of processing circuit is connected with audio amplifier circuit;The voltage value of first direct current voltage is greater than the voltage value of second direct current voltage;

[0007] Detection circuit is used for detecting first direct current voltage, and when first direct current voltage is less than or equal to first voltage threshold, output first voltage to the detection end of processing circuit;

[0008] First voltage conversion circuit is used for converting first direct current voltage, and output second voltage to the power end of audio amplifier circuit and the power end of processing circuit;

[0009] First voltage conversion circuit is also used for outputting second voltage to provide working voltage for processing circuit when second direct current voltage power -down;

[0010] Processing circuit is used for controlling audio amplifier circuit to reduce the output voltage of audio amplifier circuit when receiving first voltage.

[0011] This utility model also proposes an audio circuit, which includes a power supply circuit and the power-down processing circuit; the power supply circuit is used to provide the first DC voltage and the second DC voltage.

[0012] This invention also proposes an electronic device, which includes the power-down processing circuit or the audio circuit.

[0013] This utility model discloses a power-down processing circuit, an audio circuit, and an electronic device. The power-down processing circuit includes: a detection circuit, a first voltage conversion circuit, a processing circuit, and an audio amplification circuit. The input terminal of the detection circuit is connected to a first DC voltage, and the output terminal is connected to the detection terminal of the processing circuit. The power supply terminal of the processing circuit is connected to a second DC voltage. The input terminal of the first voltage conversion circuit is connected to the first DC voltage, and the output terminal is connected to the power supply terminal of the processing circuit and the power supply terminal of the audio amplification circuit. The output terminal of the processing circuit is connected to the audio amplification circuit. The voltage value of the first DC voltage is greater than the voltage value of the second DC voltage. The detection circuit is used to detect the first DC voltage and output a first voltage to the detection terminal of the processing circuit when the first DC voltage is less than or equal to a first voltage threshold. The first voltage conversion circuit is used to convert the first DC voltage and output a second voltage to the power supply terminal of the audio amplification circuit and the power supply terminal of the processing circuit. The first voltage conversion circuit is also used to output a second voltage to provide operating voltage for the processing circuit when the second DC voltage is de-energized. The processing circuit is used to control the audio amplification circuit to reduce its output voltage when it receives the first voltage. This invention uses a first voltage conversion circuit to step down and convert a first DC voltage, and then outputs a second voltage to the power supply terminal of the processing circuit. When the second DC voltage drops rapidly and is insufficient to support the operation of the processing circuit, the second voltage provides the operating voltage for the processing circuit, so that the processing circuit can detect the power failure through the detection circuit and control the audio amplifier circuit to reduce its output voltage, thereby avoiding the generation of pop sounds. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the first structure of the first embodiment of the power-down processing circuit of this utility model;

[0016] Figure 2 This is a second structural schematic diagram of the first embodiment of the power-down processing circuit of this utility model;

[0017] Figure 3 This is a schematic diagram of the second embodiment of the power-down handling circuit of this utility model;

[0018] Figure 4 This is a schematic diagram of the second structure of the second embodiment of the power-down processing circuit of this utility model;

[0019] Figure 5 This is a schematic diagram of the third embodiment of the power-down handling circuit of this utility model.

[0020] Explanation of icon numbers:

[0021]

[0022] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0027] Pop sounds refer to the explosive sounds produced by the transient impacts of various operations on audio devices during power-on, power-off, and after power-on stabilization.

[0028] In order to improve energy efficiency, some audio products separate the processor power supply and the amplifier power supply into two separate circuits on the power board. (See reference) Figure 1 This utility model proposes a power-down processing circuit 30 for a dual-power supply system, the power-down processing circuit 30 comprising:

[0029] The circuit consists of a detection circuit 10, a first voltage conversion circuit 20, a processing circuit 30, and an audio amplifier circuit 40.

[0030] The input terminal of the detection circuit 10 is connected to a first DC voltage, and the output terminal is connected to the detection terminal of the processing circuit 30; the power supply terminal of the processing circuit 30 is connected to a second DC voltage; the input terminal of the first voltage conversion circuit 20 is connected to the first DC voltage, and the output terminal is connected to the power supply terminal of the processing circuit 30 and the power supply terminal of the audio amplifier circuit 40; the output terminal of the processing circuit 30 is connected to the audio amplifier circuit 40; the voltage value of the first DC voltage is greater than the voltage value of the second DC voltage;

[0031] The detection circuit 10 is used to detect the first DC voltage, and when the first DC voltage is less than or equal to the first voltage threshold, it outputs the first voltage to the detection terminal of the processing circuit 30.

[0032] The first voltage conversion circuit 20 is used to convert the first DC voltage and output a second voltage to the power supply terminal of the audio amplifier circuit 40 and the power supply terminal of the processing circuit 30.

[0033] The first voltage conversion circuit 20 is also used to output a second voltage to provide operating voltage for the processing circuit 30 when the second DC voltage is de-energized.

[0034] The processing circuit 30 is used to control the audio amplifier circuit 40 to reduce the output voltage of the audio amplifier circuit 40 when the first voltage is received.

[0035] It should be noted that in this invention, the two power supplies provide a first DC voltage and a second DC voltage, respectively. The second DC voltage provides the operating voltage for the processing circuit 30, while the first DC voltage, after being converted by the first voltage conversion circuit, provides the second voltage to the power supply terminals of the audio amplifier circuit 40 and the processing circuit 30. Since the voltage value of the first DC voltage is greater than that of the second DC voltage, and the second voltage powers the processing circuit 30, the first voltage conversion circuit 20 is used to step down the first DC voltage and output the second voltage.

[0036] It is easy to understand that when the first DC voltage and the second DC voltage are both de-energized, the first DC voltage takes longer to drop to zero because the first DC voltage is greater than the second DC voltage.

[0037] This invention uses the detection circuit 10 to detect the first DC voltage, avoiding situations where the detected voltage is too low, leading to excessively rapid power loss. If the voltage is less than the first voltage threshold, the detection circuit 10 may not be able to output the first voltage to the power supply terminal of the processing circuit 30. It is readily understood that the processing circuit 30 includes a processor, whose operating voltage is typically 5V or 3.3V. The second DC voltage directly powers the processing circuit 30 and can serve as its operating voltage. The processor may include an MCU, SOC, or FPGA, etc.

[0038] This invention converts the first DC voltage using the first voltage conversion circuit 20 and outputs a second voltage to the power supply terminals of the audio amplifier circuit 40 and the processing circuit 30. It should be noted that the first DC voltage takes longer to drop to zero compared to the second DC voltage; when the second DC voltage drops below the minimum operating voltage of the processing circuit 30, the processing circuit 30 will stop working. This invention provides a power supply voltage to the processing circuit 30 by outputting a second voltage, preventing the processing circuit from stopping. It is easy to understand that the second voltage is within the operating voltage range of the processing circuit 30; even when the second DC voltage is lower than the minimum operating voltage of the processing circuit 30, the first DC voltage can still be converted by the first voltage conversion circuit 20 to provide operating voltage to the processing circuit 30, avoiding excessively rapid power loss that would cause the processing circuit 30 to stop working, resulting in the inability to detect power loss and the inability to perform fade-in / fade-out processing on the audio amplifier circuit 40, thus preventing the generation of pop sounds.

[0039] In addition, this invention uses the detection circuit 10 to detect the first DC voltage value, which is higher than the first DC voltage value and the second DC voltage value. This can prevent the second DC voltage value from being too small, and the voltage fluctuation from erroneously triggering the detection circuit 10 to output the first voltage to the processing circuit 30.

[0040] The first voltage conversion circuit 20 is used to convert the first DC voltage and output a second voltage to the power supply terminal of the audio amplifier circuit 40. It should be noted that, compared to the prior art which uses an internal linear regulator in the audio amplifier circuit 40 to convert the first DC voltage to power the operational amplifier, this invention provides the second voltage through the first voltage conversion circuit 20, thereby improving the operating efficiency of the audio amplifier circuit 40.

[0041] Fade-in and fade-out processing can gradually increase the audio volume when playback starts and gradually decrease it when playback stops, preventing sudden volume changes caused by sound switching; specifically, it is achieved by gradually reducing the output voltage of the audio amplifier circuit 40 to adjust the speaker volume.

[0042] It should be noted that the first voltage threshold, the value of the first voltage, and the value of the second voltage can be specifically determined by the R&D personnel.

[0043] This utility model discloses a power-down processing circuit 30, which includes: a detection circuit 10, a first voltage conversion circuit 20, a processing circuit 30, and an audio amplification circuit 40; the input terminal of the detection circuit 10 is connected to a first DC voltage, and the output terminal is connected to the detection terminal of the processing circuit 30; the power supply terminal of the processing circuit 30 is connected to a second DC voltage; the input terminal of the first voltage conversion circuit 20 is connected to the first DC voltage, and the output terminal is connected to the power supply terminal of the processing circuit 30 and the power supply terminal of the audio amplification circuit 40; the output terminal of the processing circuit 30 is connected to the audio amplification circuit 40; the voltage value of the first DC voltage is greater than the voltage value of the second DC voltage. The detection circuit 10 is used to detect the first DC voltage, and when the first DC voltage is less than or equal to the first voltage threshold, it outputs the first voltage to the detection terminal of the processing circuit 30; the first voltage conversion circuit 20 is used to convert the first DC voltage and output the second voltage to the power supply terminal of the audio amplifier circuit 40 and the power supply terminal of the processing circuit 30; the first voltage conversion circuit 20 is also used to output the second voltage to provide the working voltage of the processing circuit 30 when the second DC voltage drops; the processing circuit 30 is used to control the audio amplifier circuit 40 to reduce its output voltage when it receives the first voltage. This invention uses the first voltage conversion circuit 20 to step down and convert the first DC voltage, and then outputs the second voltage to the power supply terminal of the processing circuit 30. When the second DC voltage drops rapidly and is insufficient to support the operation of the processing circuit 30, the second voltage provides the working voltage of the processing circuit 30, so that the processing circuit 30 can detect the power failure through the detection circuit 10 and control the audio amplifier circuit 40 to reduce its output voltage, thus avoiding the generation of pop sounds.

[0044] Reference Figure 2 The detection circuit 10 includes:

[0045] Resistor voltage divider circuit 110 and switch circuit 120;

[0046] The input terminal of the resistor voltage divider circuit 110 is connected to the first DC voltage, and the output terminal is connected to the controlled terminal of the switch circuit 120; the output terminal of the switch circuit 120 is connected to the detection terminal of the processing circuit 30.

[0047] The resistor voltage divider circuit 110 is used to divide the first DC voltage and output a third voltage to the controlled terminal of the switch circuit 120.

[0048] The switching circuit 120 is used to output a first voltage to the detection terminal of the processing circuit 30 when the third voltage is greater than or equal to the second voltage threshold.

[0049] It should be noted that, considering that the withstand voltage of the processor's I / O port in the processing circuit 30 generally does not exceed the processor's operating voltage, and that the present invention uses a second DC voltage to power the processor, the switching circuit 120 outputs a first voltage to the processing circuit 30 when the third voltage value is greater than or equal to the second voltage threshold; it is easy to understand that the third voltage value is less than or equal to the second DC voltage value.

[0050] This invention uses a resistor voltage divider circuit 110 to divide the first DC voltage and output it to the switching circuit 120. The second voltage threshold can be the turn-on voltage of the switching circuit 120. Considering that the first DC voltage may be much higher than the second voltage threshold, the time it takes for the first DC voltage to drop to the second voltage threshold when the first DC voltage drops is too long, causing the processing circuit 30 to be insensitive to the first DC voltage drop. It is easy to understand that the voltage gain of the resistor voltage divider circuit 110, that is, the ratio of the third voltage to the first DC voltage, depends on the resistance distribution of the resistor components in the resistor voltage divider circuit 110. After determining the internal structure of the resistor voltage divider circuit 110, the voltage gain of the resistor voltage divider circuit 110 is fixed.

[0051] The switching circuit 120 is used to output a first voltage to the detection terminal of the processing circuit 30 when the third voltage is greater than or equal to the second voltage threshold.

[0052] The switching circuit 120 may include a switching device U1, which is disposed between the output terminal of the switching circuit 120 and the port of the switching circuit 120 connected to the first voltage. The second voltage threshold can be the conduction voltage value of the switching device U1. In one example, the first terminal of the switching device U1 is connected to ground, and the second terminal is connected to the detection terminal of the processing circuit 30; when the third voltage is greater than or equal to the second voltage threshold, the switching device U1 is turned on, outputting zero voltage to the detection terminal of the processing circuit 30; that is, the first voltage is zero voltage. In another example, the first terminal of the switching device U1 is connected to the first voltage, and the second terminal is connected to the detection terminal of the processing voltage; it should be noted that in this example, the source of the third voltage is not limited, and the second DC voltage can be used as the third voltage, or other voltages can be connected as the third voltage.

[0053] The resistor voltage divider circuit 110 includes:

[0054] First resistor R1 and second resistor R2;

[0055] The first end of the first resistor R1 is connected to a first DC voltage, and the second end is connected to the first end of the second resistor R2 and the controlled end of the switching circuit 120; the second end of the second resistor R2 is grounded.

[0056] The voltage gain of the resistor divider circuit 110 is DB = R2 / (R1 + R2). Here, DB is the voltage gain, R1 is the resistance value of the first resistor R1, and R2 is the resistance value of the second resistor R2. It is easy to understand that the resistance value does not change under direct current, therefore the voltage gain remains constant.

[0057] The switching circuit 120 includes:

[0058] The third resistor R3, the first capacitor C1, and the switching device U1;

[0059] The controlled terminal of the switching device U1 is connected to the second terminal of the first resistor R1, and the first terminal is connected to the first terminal of the third resistor R3. The second terminal of the third resistor R3 is connected to the second voltage and grounded. The first terminal of the switching device U1 is also connected to the detection terminal of the processing circuit 30. The first capacitor C1 is connected in parallel between the controlled terminal and the second terminal of the switching device U1.

[0060] The third resistor R3 is used to limit the current flowing through the switching device U1 when it is turned on, thus preventing damage to the switching device U1. The first capacitor C1 is used to accelerate the switching speed of the switching device U1 and filter out high-frequency components. The switching device U1 can be a transistor or a MOSFET. In one example, the switching device U1 is a transistor, and the first capacitor C1 is connected in parallel between the base and emitter of the transistor; the collector of the transistor is connected to one end of the third resistor R3 and the detection terminal of the processing circuit 30.

[0061] When the third voltage at the controlled terminal of the switching device U1 is greater than the second voltage threshold, the detection terminal of the processing circuit 30 is grounded and the first voltage is zero. In addition, when the switching device U1 is turned off, the detection terminal of the processing circuit 30 is connected to the second voltage. Thus, the voltage change at the detection terminal of the processing circuit 30 can be used to detect whether the first DC voltage has dropped.

[0062] It is readily understood that in the first embodiment, the power supply terminal of the processing circuit 30 is connected to the second DC voltage and also to the first voltage conversion circuit 20, receiving the second voltage output from the first voltage conversion circuit 20. Furthermore, the output terminal of the first voltage conversion circuit 20 is connected to the power supply terminal of the audio amplifier circuit 40 and the power supply terminal of the processing circuit 30. Although the second DC voltage can provide operating voltage to the processing circuit 30 when the second DC voltage drops rapidly, fluctuations in the second DC voltage will also cause fluctuations in the power supply voltage of the audio amplifier circuit 40, and there is a risk of current flowing back into the first voltage conversion circuit 20.

[0063] To solve the above problems, a second embodiment of this utility model is proposed, with reference to... Figure 3 The power-down processing circuit 30 further includes: a unidirectional conduction circuit 50;

[0064] The input terminal of the unidirectional conduction circuit 50 is connected to the output terminal of the first voltage conversion circuit 20, and the output terminal is connected to the power supply terminal of the processing circuit 30.

[0065] The unidirectional conduction circuit 50 is used to control the current to flow unidirectionally from the output terminal of the first voltage conversion circuit 20 to the power supply terminal of the processing circuit 30.

[0066] It should be noted that a unidirectional conduction circuit 50 is provided between the output terminal of the first voltage conversion circuit 20 and the power supply terminal of the processing circuit 30, which controls the current to flow unidirectionally from the output terminal of the first voltage circuit to the power supply terminal of the processing circuit 30; this can avoid the risk of current flowing back into the first voltage conversion circuit 20, and due to the isolation of the unidirectional conduction circuit 50, the fluctuation of the second DC voltage does not affect the power supply voltage of the audio amplifier circuit 40.

[0067] Reference Figure 4 The unidirectional conduction circuit 50 includes: a first diode D1;

[0068] The anode of the first diode D1 is connected to the output terminal of the first voltage conversion circuit 20, and the cathode is connected to the power supply terminal of the processing circuit 30.

[0069] It is readily understood that in the above embodiments, the first voltage conversion circuit 20 converts the first DC voltage into the second voltage and outputs it to the power supply terminals of the processing circuit 30 and the audio amplifier circuit 40; the second voltage needs to meet the operating voltage requirements of both the audio amplifier circuit 40 and the processing circuit 30. However, in some cases, the operating voltage of the audio amplifier circuit 40 and the operating voltage of the processing circuit 30 differ significantly, making it impossible to use the second voltage to uniformly power both the processing circuit 30 and the audio amplifier circuit 40.

[0070] To solve this problem, a third embodiment of the present invention is proposed, with reference to... Figure 5 The power-down processing circuit 30 further includes: a second voltage conversion circuit 60;

[0071] The input terminal of the second voltage conversion circuit 60 is connected to the second DC voltage, the input terminal of the second voltage conversion circuit 60 is connected to the output terminal of the first voltage conversion circuit 20, and the output terminal is connected to the power supply terminal of the processing circuit 30.

[0072] The second voltage conversion circuit 60 is used to convert the second DC voltage or the second voltage into a fourth voltage and output it to the processing circuit 30 to provide the processing circuit 30 with a working voltage.

[0073] It should be noted that this utility model includes a second voltage conversion circuit 60. When the second DC voltage is normal, the second voltage conversion circuit 60 converts the second DC voltage into the fourth voltage and outputs it to the power supply terminal of the processing circuit 30. The fourth voltage is within the operating voltage range of the processing circuit 30. When the second DC voltage is de-energized, the second voltage conversion circuit 60 converts the second voltage into the fourth voltage and outputs it to the power supply terminal of the processing circuit 30.

[0074] It is readily understood that this invention employs a second voltage conversion circuit 60 to further process the second voltage, allowing the second voltage to be outside the operating range of the processing circuit 30. This second voltage provides the operating voltage for the audio amplifier circuit 40, thereby solving the power supply problem for the audio amplifier circuit 40 and the processing circuit 30 when their operating voltages differ significantly. The fourth voltage can be determined by the researchers based on the operating voltage range of the processing circuit 30, and the second voltage can be determined by the researchers based on the operating voltage of the audio amplifier circuit 40.

[0075] This utility model also proposes an audio circuit, which includes a power supply circuit and the power-down processing circuit 30; the power supply circuit is used to provide the first DC voltage and the second DC voltage.

[0076] It should be noted that this utility model does not limit the circuit structure of the power supply circuit, the first DC voltage value, or the second DC voltage value. In particular, in one example, the first DC voltage value is 22V, and the second DC voltage value is 5V.

[0077] This invention also proposes an electronic device, which includes the power-down processing circuit 30 or the audio circuit.

[0078] The electronic device also includes a speaker connected to the output of the audio amplifier circuit 40. It is easy to understand that the electronic device emits sound through the speaker, and when the power-down processing circuit 30 detects a power failure, it controls the audio amplifier circuit 40 to reduce its output voltage. The output of the audio amplifier circuit 40 is connected to the speaker, and the sound emitted by the speaker weakens as the output voltage of the audio amplifier circuit 40 decreases, thus completing the fade-in / fade-out processing of the sound. The electronic device can be a television, MP3 player, MP4 player, speaker, tablet, or other device capable of emitting sound.

[0079] The specific structure of the power-down processing circuit 30 is as described in the above embodiments. Since the audio circuit and electronic device adopt all the technical solutions of all the above embodiments, they at least have all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The above descriptions are only optional embodiments of this utility model and do not limit the patent scope of this utility model. All equivalent structural transformations made under the utility model concept and using the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A power-down handling circuit, characterized in that, The power-down handling circuit includes: Detection circuit, first voltage conversion circuit, processing circuit and audio amplification circuit; The input terminal of the detection circuit is connected to a first DC voltage, and the output terminal is connected to the detection terminal of the processing circuit; the power supply terminal of the processing circuit is connected to a second DC voltage; the input terminal of the first voltage conversion circuit is connected to the first DC voltage, and the output terminal is connected to the power supply terminal of the processing circuit and the power supply terminal of the audio amplifier circuit; the output terminal of the processing circuit is connected to the audio amplifier circuit; the voltage value of the first DC voltage is greater than the voltage value of the second DC voltage. The detection circuit is used to detect the first DC voltage, and when the first DC voltage is less than or equal to a first voltage threshold, output the first voltage to the detection terminal of the processing circuit; The first voltage conversion circuit is used to convert the first DC voltage and output a second voltage to the power supply terminal of the audio amplifier circuit and the power supply terminal of the processing circuit. The first voltage conversion circuit is also used to output a second voltage to provide operating voltage for the processing circuit when the second DC voltage is de-energized; The processing circuit is configured to control the audio amplifier circuit to reduce the output voltage of the audio amplifier circuit when the first voltage is received.

2. The power-down processing circuit as described in claim 1, characterized in that, The detection circuit includes: Resistor voltage divider circuit and switching circuit; The input terminal of the resistor voltage divider circuit is connected to the first DC voltage, and the output terminal is connected to the controlled terminal of the switching circuit; the output terminal of the switching circuit is connected to the detection terminal of the processing circuit. The resistor voltage divider circuit is used to divide the first DC voltage and output a third voltage to the controlled terminal of the switching circuit. The switching circuit is used to output a first voltage to the detection terminal of the processing circuit when the third voltage is greater than or equal to the second voltage threshold.

3. The power-down processing circuit as described in claim 2, characterized in that, The resistor voltage divider circuit includes: First resistor and second resistor; The first end of the first resistor is connected to a first DC voltage, and the second end is connected to the first end of the second resistor and the controlled end of the switching circuit; the second end of the second resistor is grounded.

4. The power-down processing circuit as described in claim 3, characterized in that, The switching circuit includes: The third resistor, the first capacitor, and the switching device; The controlled terminal of the switching device is connected to the second terminal of the first resistor, the first terminal is connected to the first terminal of the third resistor, the second terminal of the third resistor is connected to the second voltage, and the second terminal is grounded; the first terminal of the switching device is also connected to the detection terminal of the processing circuit; the first capacitor is connected in parallel between the controlled terminal and the second terminal of the switching device.

5. The power-down processing circuit as described in any one of claims 1 to 4, characterized in that, The power-down processing circuit also includes: a unidirectional conduction circuit; The input terminal of the unidirectional conduction circuit is connected to the output terminal of the first voltage conversion circuit, and the output terminal is connected to the power supply terminal of the processing circuit. The unidirectional conduction circuit is used to control the current to flow unidirectionally from the output terminal of the first voltage conversion circuit to the power supply terminal of the processing circuit.

6. The power-down processing circuit as described in claim 5, characterized in that, The unidirectional conduction circuit includes: a first diode; The anode of the first diode is connected to the output terminal of the first voltage conversion circuit, and the cathode is connected to the power supply terminal of the processing circuit.

7. The power-down processing circuit as described in any one of claims 1 to 4, characterized in that, The power-down processing circuit further includes: a second voltage conversion circuit; The input terminal of the second voltage conversion circuit is connected to the second DC voltage, the input terminal of the second voltage conversion circuit is connected to the output terminal of the first voltage conversion circuit, and the output terminal is connected to the power supply terminal of the processing circuit. The second voltage conversion circuit is used to convert the second DC voltage or the second voltage into a fourth voltage and output it to the processing circuit to provide the processing circuit with a working voltage.

8. An audio circuit, characterized in that, The audio circuit includes a power supply circuit and a power-down processing circuit as described in any one of claims 1 to 7; the power supply circuit is used to provide the first DC voltage and the second DC voltage.

9. An electronic device, characterized in that, The electronic device includes a power-down processing circuit as described in any one of claims 1 to 7, or an audio circuit as described in claim 8.

10. The electronic device as claimed in claim 9, characterized in that, The electronic device also includes a speaker connected to the output of the audio amplifier circuit.

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