Power amplifier power supply circuit and audio equipment

Abstract

The utility model provides a power amplifier power supply circuit and audio equipment, the power amplifier power supply circuit comprises an AC input circuit, an AC-DC rectifier, at least two DC-DC step-down transformers and at least two DC turn-off control circuits, the DC turn-off control circuits comprise optocouplers and switch tubes; the AC-DC rectifier is electrically connected with the AC input circuit and the DC-DC step-down transformer, the DC-DC step-down transformer is also used for being electrically connected with an external power amplifier chip, and the switching tube is electrically connected with the optocoupler and the DC-DC step-down transformer. Through the implementation of the power amplifier power supply circuit, the voltage is reduced by the at least two DC-DC step-down transformers and then is transmitted to the external power amplifier chip, and the voltages output by different DC-DC step-down transformers can be the same or different, so that when the power amplifier power supply circuit is used for supplying power, a plurality of groups of direct current with the same or different values can be obtained; the power utilization requirements of different power amplifier chips are met, and the adaptability and reliability of the power amplifier power supply are effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and in particular to a power amplifier circuit and an audio device. Background Art

[0002] Amplifier chips can amplify low-amplitude electrical signals to a power level sufficient to drive a load, and are usually used in scenarios such as audio enhancement or power amplification. The power supply voltage requirements of amplifier chips in different types of amplifier products are different. For example, an amplifier chip with a power consumption of less than 1500W may require different power supply voltages such as 32V, 28V, and 24V. However, the amplifier power supply in the related technology can usually only output one power supply voltage or several identical power supply voltages, which cannot meet the different power supply requirements of amplifier products. The reliability and applicability of the power supply are poor. Utility Model Content

[0003] The utility model provides a power amplifier circuit and an audio device, aiming to solve the problems of low reliability and poor applicability of the power amplifier circuit in the related art.

[0004] In order to solve the above technical problems, the first aspect of the utility model provides a power amplifier power supply circuit, including: an AC input circuit, an AC-DC rectifier, at least two DC-DC bucks and at least two DC shutdown control circuits, the DC shutdown control circuit includes an optocoupler and a switch tube; the AC-DC rectifier is electrically connected to the AC input circuit and the DC-DC buck respectively, the DC-DC buck is also used to be electrically connected to an external power amplifier chip, and the switch tube is electrically connected to the optocoupler and the DC-DC buck respectively.

[0005] Furthermore, the AC input circuit includes an AC filter and a lightning protection circuit, the AC filter is electrically connected to the AC power supply and one end of the lightning protection circuit respectively, and the other end of the lightning protection circuit is electrically connected to the AC-DC rectifier.

[0006] Furthermore, the lightning protection circuit includes a first varistor, a second varistor, a third varistor and a gas discharge tube, one end of the first varistor and the second varistor are electrically connected to the AC filter and the first end of the AC-DC converter, respectively, the other end of the first varistor is electrically connected to the AC filter, the second end of the AC-DC converter and one end of the third varistor, the other end of the third varistor is electrically connected to one end of the gas discharge tube and the other end of the second varistor, and the other end of the gas discharge tube is grounded.

[0007] Furthermore, the DC shutdown circuit also includes a first diode, a second diode, a first resistor, a second resistor and a first capacitor; the first end and the second end of the optocoupler are used to be electrically connected to an external control signal generator, the third end of the optocoupler is electrically connected to the third end of the AC-DC rectifier, the positive electrode of the second diode, and the first end of the DC-DC buck, respectively, the negative electrode of the second diode is electrically connected to the fourth end of the optocoupler, the fourth end of the AC-DC rectifier, and one end of the first resistor, respectively, the other end of the first resistor is electrically connected to one end of the second resistor, one end of the first capacitor and one end of the switch tube, the other end of the second resistor, the other end of the first capacitor and the second end of the switch tube are all electrically connected to the third end of the optocoupler, the third end of the switch tube is electrically connected to the negative electrode of the first diode, and the positive electrode of the first diode is electrically connected to the second end of the DC-DC buck.

[0008] Furthermore, the power amplifier power supply circuit also includes a filter circuit, and the filter circuit is electrically connected to the third terminal and the fifth terminal of the AC-DC rectifier respectively.

[0009] Furthermore, the filtering circuit includes a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor and an eleventh capacitor, and each capacitor is electrically connected to the third end and the fifth end of the AC-DC rectifier respectively.

[0010] A second aspect of the present invention provides an audio device, comprising a power amplifier chip and the power amplifier power supply circuit as described in the first aspect of the present invention, wherein the power amplifier power supply circuit is electrically connected to the power amplifier chip.

[0011] From the above description, it can be seen that the utility model converts the AC power transmitted by the AC input circuit through an AC-DC rectifier and outputs DC power, which is then stepped down by at least two DC-DC bucks and transmitted to an external power amplifier chip. The voltages output by different DC-DC bucks can be the same or different. Therefore, when the power amplifier power supply circuit is used for power supply, multiple groups of DC power with the same or different values ​​can be obtained to meet the power requirements of different power amplifier chips, effectively improving the adaptability of the power amplifier power supply. At the same time, by setting a DC shutdown control circuit, the corresponding DC-DC buck can be selectively shut down to avoid AC surge damage to the equipment caused by repeatedly turning on and off the AC power supply during the power amplifier debugging process, thereby ensuring the reliability and flexibility of the power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a power amplifier power supply circuit of an embodiment of the utility model;

[0013] Figure 2It is a circuit principle diagram of an AC input circuit of an embodiment of the utility model;

[0014] Figure 3 It is a circuit principle diagram of a power amplifier power supply circuit of an embodiment of the utility model;

[0015] Figure 4 It is a circuit principle diagram of another power amplifier power supply circuit of an embodiment of the utility model. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. In addition, the technical features involved in the various embodiments of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0017] In the related art, there are problems of low reliability and poor applicability of the power amplifier power supply. Therefore, an embodiment of the utility model provides a power amplifier power supply circuit.

[0018] like Figure 1 The figure shows a schematic diagram of the structure of a power amplifier power supply circuit provided in the present embodiment, wherein the power amplifier power supply circuit comprises: an AC input circuit 100, an AC-DC rectifier 200, at least two DC-DC bucks 300 and at least two DC shutdown control circuits 400, wherein the DC shutdown control circuit 400 comprises an optocoupler 410 and a switch tube 420; the AC-DC rectifier 200 is electrically connected to the AC input circuit 100 and the DC-DC buck 300 respectively, the DC-DC buck 300 is also used to be electrically connected to an external power amplifier chip 500, and the switch tube 420 is electrically connected to the optocoupler 410 and the DC-DC buck 300 respectively.

[0019] Specifically, the power amplifier power supply circuit of this embodiment converts the AC power transmitted by the AC input circuit 100 through the AC-DC rectifier 200 and outputs DC power, which is then stepped down by at least two DC-DC bucks 300 and transmitted to the external power amplifier chip 500. The voltages output by different DC-DC bucks 300 can be the same or different, so that when the power amplifier power supply circuit is used for power supply, multiple groups of the same or different DC power can be obtained to meet the power requirements of different power amplifier chips 500, effectively improving the adaptability of the power amplifier power supply. At the same time, by setting a DC shutdown control circuit 400, the corresponding DC-DC buck 300 can be selectively shut down to avoid AC surge damage to the device caused by repeatedly turning on and off the AC power supply during the power amplifier debugging process. At the same time, the output path can also be selected to ensure the reliability and flexibility of the power supply circuit.

[0020] like Figure 2 The circuit diagram of an AC input circuit provided by this embodiment is shown in FIG. Figure 2 The AC input circuit 100 includes an AC filter U1 and a lightning protection circuit. The AC filter U1 is electrically connected to the AC power supply and one end of the lightning protection circuit respectively, and the other end of the lightning protection circuit is electrically connected to the AC-DC rectifier 200.

[0021] Specifically, the lightning protection circuit includes a first varistor CNR1, a second varistor CNR2, a third varistor CNR3 and a gas discharge tube GDT3, one end of the first varistor CNR1 and the second varistor CNR2 are electrically connected to the first end of the AC filter U1 and the AC-DC converter, respectively, the other end of the first varistor CNR1 is electrically connected to the second end of the AC filter U1, the AC-DC converter and one end of the third varistor CNR3, the other end of the third varistor CNR3 is electrically connected to one end of the gas discharge tube GDT3 and the other end of the second varistor CNR2, and the other end of the gas discharge tube GDT3 is grounded.

[0022] In this embodiment, the AC input circuit 100 is provided with an AC filter U1 and a lightning protection circuit, wherein the AC filter U1 is used to filter out the clutter signal of the input 220V AC power to obtain a cleaner 220V AC power, and then input it into the AC-DC rectifier 200 through the lightning protection circuit composed of a varistor and a gas discharge tube GDT3. The lightning protection circuit can prevent the input current from being too large, causing damage to the device and the overall circuit. In addition, the AC power in this embodiment can be connected to the AC filter U1 through the connector J1, and the L end of the AC filter U1 corresponds to the live wire and the N end corresponds to the neutral wire.

[0023] like Figure 3 The circuit diagram of a power amplifier power supply circuit provided by this embodiment is shown in FIG. Figure 3The DC shutdown circuit also includes a first diode D1 (D3), a second diode D2 (D4), a first resistor R2 (R5), a second resistor R3 (R6) and a first capacitor C3 (C9); the first end 1 and the second end 2 of the optocoupler U4 / U6 (410) are used to be electrically connected to an external control signal generator, the third end 3 of the optocoupler U4 is respectively electrically connected to the third end -V of the AC-DC rectifier U2 (200), the positive electrode of the second diode D2 (D4), and the first end SG of the DC-DC buck U3 / U5 (300), the cathode of the second diode D2 (D4) is respectively electrically connected to the fourth end 4 of the optocoupler U4, the AC-DC rectifier U 2 is electrically connected to a fourth end EN of the first resistor R2 (R5), the other end of the first resistor R2 (R5) is electrically connected to one end of the second resistor R3 (R6), one end of the first capacitor C3 (C9) and one end of the switch tube Q1 / Q2 (420), the other end of the second resistor R3 (R6), the other end of the first capacitor C3 (C9) and the second end of the switch tube Q1 (Q2) are all electrically connected to the third end 3 of the optical coupler U4, the third end of the switch tube Q1 (Q2) is electrically connected to the cathode of the first diode D1 (D3), and the anode of the first diode D1 (D3) is electrically connected to the second end CNT of the DC-DC buck U3 (U5). The external control signal generator is connected to the circuit through the connector J2.

[0024] For further information, see Figure 3 The power amplifier power supply circuit also includes a third resistor R1, a second capacitor C1 and a third capacitor C2 (C8), the second capacitor C1 is electrically connected to the first end L and the second end N of the AC-DC rectifier U2 respectively, one end of the third resistor R1 is electrically connected to the fourth end EN of the AC-DC rectifier U2, the other end of the third resistor R1 is electrically connected to the fifth end +V of the AC-DC rectifier U2 and the third end +Vin of the DC-DC buck U3 (U5), the fourth end of the DC-DC buck U3 (U5) is electrically connected to the third end of the AC-DC rectifier 200, one end of the third capacitor C2 (C8) is electrically connected to the fourth end -Vin of the DC-DC buck U3 (U5), and the other end of the third capacitor C2 (C8) is grounded. Among them, the second capacitor C1 and the third capacitor C2 (C8) can be used to improve the stability of the buck and optimize the circuit performance. The third resistor R1 is a pull-up resistor, which can be used to keep the level of the enable end of the AC-DC rectifier 200 stable.

[0025] Specifically, in the present embodiment, the DC-DC buck 300 of the power amplifier power supply circuit can be set to two or more, and each DC-DC buck U3 (U5) is provided with a DC shutdown control circuit 400 for shutting down the corresponding DC-DC buck U3 (U5), so that there is no need to shut down the AC input to avoid surge damage to the device. The structures of each DC-DC buck U3 (U5) and each DC shutdown control circuit 400 are similar. Taking the first DC-DC buck U3 and the first DC shutdown control circuit 400 as an example, the DC shutdown control circuit 400 is mainly composed of an optical coupler U4, a diode, a resistor, a capacitor, and a switch tube such as a triode. The first diode D1 is set at the enable terminal CNT of the DC-DC buck U3, and the second diode D2 is set at the enable terminal of the AC-DC rectifier U2. By setting two diodes, voltage reverse series can be prevented. The resistor and the capacitor can be used to ensure the accuracy of the on-off control of the switch tube Q1, prevent mis-on or on-off delay, and can also protect the switch tube Q1. In this embodiment, the DC shutdown circuit can control the on and off of the switch tube Q1 by controlling the optocoupler U4. When the first end of the optocoupler U4 receives a high level, the optocoupler U4 is turned on. At this time, the switch tube Q1 receives a low level signal and is turned off, thereby turning off the output of the DC-DC buck U3. The AC-DC rectifier U2 in this embodiment can use an AC-DC rectifier of model VI-ARMB-T21, and the DC-DC buck U3 can use a buck of model PAF750.

[0026] like Figure 4 FIG. 1 is a circuit diagram of another power amplifier power supply circuit provided in this embodiment, see Figure 4 The power amplifier power supply circuit also includes a filter circuit, which is electrically connected to the third terminal -V and the fifth terminal +V of the AC-DC rectifier U2 respectively.

[0027] Specifically, the filtering circuit includes a fourth capacitor CE1, a fifth capacitor CE2, a sixth capacitor CE3, a seventh capacitor CE4, an eighth capacitor CE5, a ninth capacitor CE6, a tenth capacitor CE7 and an eleventh capacitor CE8, and each capacitor is electrically connected to the third terminal -V and the fifth terminal +V of the AC-DC rectifier U2 respectively.

[0028] In this embodiment, after being processed by the AC-DC rectifier U2, a 310V direct current can be obtained. To ensure the stability of the 310V direct current, it is necessary to filter out the clutter through a filter circuit. The filter circuit of this embodiment is implemented by 8 high-voltage filter capacitors, which can effectively filter out the clutter signals in the direct current. After that, the filtered direct current is transmitted to each DC-DC buck U3 (U5) for buck conversion, so that the DC 32V, 28V, 24V, 15V, 12V and other voltages required by the power amplifier chip 500 can be output. In this embodiment, the first DC-DC buck U3 is used to output 32V direct current, and the first DC-DC buck U5 is used to output 24V direct current. It should be noted that the DC-DC buck U3 (U5) in this embodiment can be replaced according to the required power supply voltage requirements, and the corresponding structural dimensions do not need to be changed. The composition is highly flexible and the design cost can also be saved.

[0029] For further information, see Figure 4 The power amplifier power supply circuit also includes an adjustable resistor VR1 (VR2) and a fourth resistor R4 (R7). The fifth terminal +S of the DC-DC buck U3 (U5) is electrically connected to the sixth terminal +Vout of the DC-DC buck U3 (U5) through the adjustable resistor VR1 (VR2). The sixth terminal +Vout and the seventh terminal -Vout of the DC-DC buck U3 (U5) are used to be electrically connected to the power amplifier chip 500. The eighth terminal -S of the DC-DC buck U3 (U5) is electrically connected to the seventh terminal -Vout of the DC-DC buck U3 (U5). The ninth terminal TRIM of the DC-DC buck U3 (U5) is electrically connected to the seventh terminal -Vout of the DC-DC buck U3 (U5) through the fourth resistor R4 (R7).

[0030] For further information, see Figure 4 The power amplifier power supply circuit also includes a twelfth capacitor C4 (C10), a thirteenth capacitor C7 (C13), a first electrolytic capacitor C5 (C11) and a second electrolytic capacitor C6 (C12). The twelfth capacitor C4 (C10), the first electrolytic capacitor C5 (C11) and the second electrolytic capacitor C6 (C12) are electrically connected to the sixth terminal +Vout and the seventh terminal -Vout of the DC-DC buck U3 (U5), respectively. One end of the thirteenth capacitor C7 (C13) is electrically connected to the seventh terminal -Vout of the DC-DC buck U3 (U5), and the other end of the thirteenth capacitor C7 (C13) is grounded.

[0031] In this embodiment, a capacitor is provided between the two ends of the DC-DC buck U3 (U5) outputting to the external power amplifier chip 500, which can be used to filter the output voltage. The S end and the TRIM end of the DC-DC buck U3 (U5) are both connected to a resistor, and the stability and accuracy of the output voltage can be adjusted by changing the resistance value of the resistor.

[0032] The power amplifier power supply circuit provided by the embodiment of the utility model converts the alternating current transmitted by the alternating current input circuit through an AC-DC rectifier and outputs direct current, which is then stepped down by at least two DC-DC bucks and transmitted to an external power amplifier chip. The voltages output by different DC-DC bucks can be the same or different, so that when the power amplifier power supply circuit is used for power supply, multiple groups of the same or different direct currents can be obtained to meet the power requirements of different power amplifier chips, effectively improving the adaptability of the power amplifier power supply. At the same time, by setting a DC shutdown control circuit, the corresponding DC-DC buck can be selectively shut down to avoid AC surge damage to the equipment caused by repeatedly turning on and off the AC power supply during the power amplifier debugging process, thereby ensuring the reliability and flexibility of the power supply circuit.

[0033] The embodiment of the utility model further provides an audio device, which includes a power amplifier chip and the power amplifier power circuit, wherein the power amplifier power circuit is electrically connected to the power amplifier chip.

[0034] It should be noted that the various embodiments in the present invention are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0035] It should also be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0036] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined in the present invention may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in the present invention, but will conform to the widest range consistent with the principles and novel features disclosed in the present invention.

Claims

1. A power amplifier power supply circuit, characterized in that: include: An AC input circuit, an AC-DC rectifier, at least two DC-DC bucks and at least two DC shutdown control circuits, wherein the DC shutdown control circuit includes an optocoupler and a switch tube; the AC-DC rectifier is electrically connected to the AC input circuit and the DC-DC buck respectively, the DC-DC buck is also used to be electrically connected to an external power amplifier chip, and the switch tube is electrically connected to the optocoupler and the DC-DC buck respectively.

2. The power amplifier power supply circuit according to claim 1, characterized in that: The AC input circuit includes an AC filter and a lightning protection circuit. The AC filter is electrically connected to an AC power source and one end of the lightning protection circuit respectively, and the other end of the lightning protection circuit is electrically connected to the AC-DC rectifier.

3. The power amplifier power supply circuit according to claim 2, characterized in that: The lightning protection circuit includes a first varistor, a second varistor, a third varistor and a gas discharge tube, one end of the first varistor and the second varistor are electrically connected to the first end of the AC filter and the AC-DC rectifier, respectively, the other end of the first varistor is electrically connected to the second end of the AC filter, the AC-DC rectifier and one end of the third varistor, the other end of the third varistor is electrically connected to one end of the gas discharge tube and the other end of the second varistor, and the other end of the gas discharge tube is grounded.

4. The power amplifier power supply circuit according to claim 1, characterized in that: The DC shutdown circuit also includes a first diode, a second diode, a first resistor, a second resistor and a first capacitor; the first end and the second end of the optocoupler are used to be electrically connected to an external control signal generator, the third end of the optocoupler is electrically connected to the third end of the AC-DC rectifier, the positive electrode of the second diode, and the first end of the DC-DC buck respectively, the negative electrode of the second diode is electrically connected to the fourth end of the optocoupler, the fourth end of the AC-DC rectifier, and one end of the first resistor respectively, the other end of the first resistor is electrically connected to one end of the second resistor, one end of the first capacitor and one end of the switch tube respectively, the other end of the second resistor, the other end of the first capacitor and the second end of the switch tube are all electrically connected to the third end of the optocoupler, the third end of the switch tube is electrically connected to the negative electrode of the first diode, and the positive electrode of the first diode is electrically connected to the second end of the DC-DC buck.

5. The power amplifier power supply circuit according to claim 4, characterized in that: It also includes a third resistor, a second capacitor and a third capacitor, wherein the second capacitor is electrically connected to the first end and the second end of the AC-DC rectifier respectively, one end of the third resistor is electrically connected to the fourth end of the AC-DC rectifier, the other end of the third resistor is electrically connected to the fifth end of the AC-DC rectifier and the third end of the DC-DC buck respectively, the fourth end of the DC-DC buck is electrically connected to the third end of the AC-DC rectifier, one end of the third capacitor is electrically connected to the fourth end of the DC-DC buck, and the other end of the third capacitor is grounded.

6. The power amplifier power supply circuit according to claim 5, characterized in that: It also includes a filter circuit, which is electrically connected to the third terminal and the fifth terminal of the AC-DC rectifier respectively.

7. The power amplifier power supply circuit according to claim 6, characterized in that: The filter circuit includes a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor and an eleventh capacitor, and each capacitor is electrically connected to the third end and the fifth end of the AC-DC rectifier respectively.

8. The power amplifier power supply circuit according to claim 1, characterized in that: It also includes an adjustable resistor and a fourth resistor, the fifth end of the DC-DC buck is electrically connected to the sixth end of the DC-DC buck through the adjustable resistor, the sixth end and the seventh end of the DC-DC buck are used to be electrically connected to the power amplifier chip, the eighth end of the DC-DC buck is electrically connected to the seventh end of the DC-DC buck, and the ninth end of the DC-DC buck is electrically connected to the seventh end of the DC-DC buck through the fourth resistor.

9. The power amplifier power supply circuit according to claim 8, characterized in that: It also includes a twelfth capacitor, a thirteenth capacitor, a first electrolytic capacitor and a second electrolytic capacitor, the twelfth capacitor, the first electrolytic capacitor and the second electrolytic capacitor are electrically connected to the sixth end and the seventh end of the DC-DC buck, respectively, one end of the thirteenth capacitor is electrically connected to the seventh end of the DC-DC buck, and the other end of the thirteenth capacitor is grounded.

10. An audio device, characterized in that: It comprises a power amplifier chip and a power amplifier power supply circuit as claimed in any one of claims 1 to 9, wherein the power amplifier power supply circuit is electrically connected to the power amplifier chip.

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