Linear power module output audio control type BUCK power amplifier power supply

Abstract

The utility model belongs to the technical field of electronic circuit, specifically disclose a linear power module output's audio control type BUCK power amplifier power, including power amplifier transformer module, two -way audio control BUCK circuit and linear power module, power amplifier transformer module exports two independent DC drive power and two independent DC reference power to two -way audio control BUCK circuit, two -way audio control BUCK circuit exports two adjustable power amplifier voltage to linear power module, linear power module carries out low -pass filtering and active amplification processing to two adjustable power amplifier voltage, exports two purification power amplifier voltage to load. The utility model integrates the advantages that switching power supply is high in efficiency and linear power module output ripple is small and has less interference, and the compatibility contradiction between power amplifier power efficiency and output voltage quality is solved well, and the comprehensive performance is excellent. And the size of power amplifier power voltage is further improved the efficiency of power amplifier power with equivalent audio voltage signal proportionally.

Description

Technical Field

[0001] This utility model belongs to the field of electronic circuit technology, specifically relating to a volume-controlled BUCK power amplifier power supply with linear power module output. Background Technology

[0002] A power supply is a crucial component of an audio power amplifier; a good audio power amplifier must first have a high-quality power supply. Traditional audio power supplies come in two types: the first is a linear power module, which has the advantages of low ripple and interference, but the disadvantages of high power consumption and low efficiency. The second is a switching power supply, whose characteristics are the opposite of the linear power module. Traditional audio power supplies often suffer from a compatibility issue between power efficiency and output voltage quality. For example, patent CN106101933B proposes a method and device for adjusting the volume of an amplifier system, achieving the goal of adjusting the output voltage of the power module according to the volume level, but it lacks effective means to reduce output voltage ripple or noise interference. Patent CN109101067B proposes a low-dropout linear regulator with dual power rails, which can solve the problem of low energy conversion efficiency of the LDO inside the BUCK converter chip, and has a positive effect on reducing noise and ripple output and improving power stability. However, its disadvantage is that it cannot use audio signals to adjust the dual power supply voltages over a wide range, and its effect on improving power efficiency is not yet significant. Therefore, there is an urgent need for a power amplifier power supply that can effectively balance power efficiency and output voltage quality. Utility Model Content

[0003] The purpose of this invention is to provide a volume-controlled BUCK power amplifier power supply with linear power module output, in order to solve the above-mentioned problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a volume-controlled BUCK amplifier power supply with a linear power module output, comprising an amplifier transformer module, a dual-channel volume-controlled BUCK circuit, and a linear power module. The amplifier transformer module is used to connect to an external power supply and to transform and rectify the external power supply, outputting two independent DC drive power supplies and two independent DC reference power supplies to the dual-channel volume-controlled BUCK circuit. The dual-channel volume-controlled BUCK circuit includes two BUCK circuits, and the two independent DC drive power supplies are used to drive the two BUCK circuits in the dual-channel volume-controlled BUCK circuit respectively. The two-channel BUCK circuit is used to control the equivalent audio voltage signal of the two independent DC reference power supplies and output two adjustable power amplifier voltages to the linear power supply module. The dual-channel volume control BUCK circuit is also used to transmit the two independent DC reference power supplies to the linear power supply module. The linear power supply module is used to perform low-pass filtering and active amplification on the two adjustable power amplifier voltages to obtain two purified power amplifier voltages, and to perform voltage regulation on the two independent DC reference power supplies to obtain two power amplifier preamplifier power supplies. The two purified power amplifier voltages and the two power amplifier preamplifier power supplies are then output to the external load.

[0005] In one possible design, a dual-channel PWM processing circuit is also included. The dual-channel volume control BUCK circuit further includes two sampling comparison circuits. The two sampling comparison circuits are used to divide and sample the adjustable power amplifier voltages output by the two BUCK circuits to obtain two sampled voltages. The two sampled voltages are then compared with a reference comparison voltage, and two error comparison signals are output to the dual-channel PWM processing circuit. The dual-channel PWM processing circuit receives the two error comparison signals and outputs two control signals to the two BUCK circuits to adjust the adjustable power amplifier voltages output by the two BUCK circuits.

[0006] In one possible design, a dual-channel overcurrent protection circuit is also included. This circuit samples the load's operating current in two channels to obtain a current feedback signal, which is then transmitted to a dual-channel tone control BUCK circuit. The dual-channel tone control BUCK circuit then transmits the current feedback signal to a dual-channel PWM processing circuit. This dual-channel PWM processing circuit receives the current feedback signal and controls the output of the dual-channel tone control BUCK circuit based on the current feedback signal.

[0007] In one possible design, the dual-channel volume control BUCK circuit also includes an internal power supply module, which is used to transform the DC reference power supply to obtain an internal power supply, and transmit the internal power supply to the dual-channel PWM processing circuit to power the dual-channel PWM processing circuit.

[0008] In one possible design, the dual-channel volume control BUCK circuit also includes a power protection circuit that controls the output of the internal power module based on a current feedback signal.

[0009] In one possible design, the dual-channel PWM processing circuit is also used to sample the load's dual-channel operating voltage to obtain a voltage feedback signal, and control the output of the dual-channel volume control BUCK circuit based on the voltage feedback signal.

[0010] In one possible design, the dual-channel PWM processing circuit includes two UC3842-type PWM processing processors.

[0011] In one possible design, the power amplifier transformer module includes multiple sets of transformer windings and a bridge rectifier circuit, which are used to transform and rectify the external power supply, respectively.

[0012] Beneficial effects: This invention integrates the advantages of high efficiency of switching power supplies and low output ripple and interference of linear power modules, effectively resolving the compatibility contradiction between power amplifier power supply efficiency and output voltage quality, resulting in excellent overall performance. Furthermore, this invention uses an equivalent audio voltage signal to proportionally control the magnitude of the power amplifier power supply voltage, further improving the power amplifier power supply efficiency. Attached Figure Description

[0013] 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 these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the power amplifier power supply architecture of this utility model; Figure 2 This is a circuit diagram of the power amplifier transformer module; Figure 3 This is a circuit diagram of a dual-channel PWM processing circuit. Figure 4 This is a circuit diagram of a dual-channel volume control BUCK circuit; Figure 5 This is a circuit diagram of a dual-channel overcurrent protection circuit; Figure 6 This is a circuit diagram of a linear power supply module.

[0015] In the diagram: 101, Dual-channel overcurrent protection circuit; 102, Power amplifier transformer module; 103, Dual-channel volume control BUCK circuit; 104, Linear power supply module; 105, Load; 106, Dual-channel PWM processing circuit. Detailed Implementation

[0016] It should be noted that the descriptions of these embodiments are intended to aid in understanding the present invention, but do not constitute a limitation thereof. The specific structural and functional details disclosed herein are merely for describing exemplary embodiments of the present invention. However, the present invention may be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0017] It should be understood that, unless otherwise explicitly specified and limited, the corresponding terms should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be an electrical connection, a direct connection, or an indirect connection through an intermediate medium; it can also refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments according to the specific circumstances.

[0018] Specific details are provided in the following description to provide a complete understanding of the exemplary embodiments. However, those skilled in the art will understand that the exemplary embodiments can be implemented without these specific details. For example, the system may be shown in block diagrams to avoid obscuring the example with unnecessary details. In other embodiments, well-known processes, structures, and techniques may be shown without non-essential details to avoid obscuring the embodiments.

[0019] Example: This embodiment provides a volume-controlled BUCK amplifier power supply with linear power module output, such as... Figure 1As shown, the system includes a power amplifier transformer module 102, a dual-channel volume control BUCK circuit 103, and a linear power supply module 104. The power amplifier transformer module 102 is used to connect to an external power supply and to transform and rectify the external power supply, outputting two independent DC drive power supplies and two independent DC reference power supplies to the dual-channel volume control BUCK circuit 103. The dual-channel volume control BUCK circuit 103 includes two BUCK circuits. The two independent DC drive power supplies are used to drive the two BUCK circuits in the dual-channel volume control BUCK circuit 103 respectively. The system controls the two independent DC reference power supplies with equivalent audio voltage signals and outputs two adjustable power amplifier voltages to the linear power supply module 104. The dual-channel volume control BUCK circuit 103 is also used to transmit the two independent DC reference power supplies to the linear power supply module 104. The linear power supply module 104 is used to perform low-pass filtering and active amplification on the two adjustable power amplifier voltages to obtain two purified power amplifier voltages, and to perform voltage regulation on the two independent DC reference power supplies to obtain two power amplifier preamplifier power supplies. The system then outputs the two purified power amplifier voltages and the two power amplifier preamplifier power supplies to the external load 105.

[0020] In practical implementation, the power amplifier transformer module 102 transforms and rectifies the external power supply, outputting two independent DC drive power supplies (15V) and two independent DC reference power supplies (+44V / -44V) to the dual-channel volume control BUCK circuit 103. The two BUCK circuits in the dual-channel volume control BUCK circuit 103 operate based on the DC drive power supply (15V) and control the two independent DC reference power supplies with equivalent audio voltage signals, outputting two adjustable power amplifier voltages (+44V~-44V). The two adjustable power amplifier voltages (+(8V~44V) and -(8V~44V)) are output from the BUCK circuit and contain significant ripple and high-frequency interference. After low-pass filtering and active amplification in the linear power module 104, these two voltages are purified into two power amplifier voltages (+(6V~42V) and -(6V~42V)), which are then output to the external load 105, resulting in a high-efficiency and high-quality power amplifier power supply. Simultaneously, the dual-channel volume control BUCK circuit 103 sends the +44V and -44V DC reference power supply voltages to the linear power module 104. After simple voltage regulation, the linear power module 104 outputs two relatively pure voltages (+39V and -39V) as the power amplifier preamplifier power supply.

[0021] The power amplifier transformer module 102 includes a power amplifier transformer, which has at least one set of dual 32V (or other voltage levels) main transformer windings and its corresponding AC / DC circuit (bridge rectifier circuit) for outputting two symmetrical power amplifier power supplies, and two sets of independent 15V transformer windings and their corresponding AC / DC circuit (bridge rectifier circuit) for outputting two independent 15V DC drive power supplies for driving the switching transistors of the two BUCK circuits in the dual-channel volume control BUCK circuit 103. Figure 2 As shown, the 220V external AC power is input through socket J2. After common-mode interference signals are filtered out by the common-mode filter circuit composed of C44, T1, and C46, ​​it is sent to the primary winding of the power amplifier transformer T2. The dual 32V AC power output from the secondary winding of the power amplifier transformer T2 is rectified by rectifier bridge D12. The positive voltage is output from point M1, filtered by C45 and C47, and output as +44V (DC reference power supply) from port IO5. The negative voltage is output from point N1, filtered by C48 and C49, and output as -44V (DC reference power supply) from port IO6.

[0022] One secondary winding of the power amplifier transformer T2 outputs a 15V AC voltage. After rectification and filtering by D11 and C43, and regulation by D10, a +15V turn-on voltage (DC drive power supply) is output from port A31, and a -5V turn-off voltage (relative to the potential of port A32) is output from port A33. This +15V and -5V voltages provide the positive and negative power supplies to the optocoupler driver U3 in the dual-channel volume control BUCK circuit 103, respectively. The other secondary winding of the power amplifier transformer T2 outputs a 15V AC voltage. After rectification and filtering by D14 and C50, and regulation by D13, a +15V turn-on voltage (DC drive power supply) is output from port A41, and a -5V turn-off voltage (relative to the potential of port A42) is output from port A43. This +15V and -5V voltages provide the positive and negative power supplies to the optocoupler driver U5 in the dual-channel volume control BUCK circuit 103, respectively.

[0023] Furthermore, this power amplifier power supply also includes a dual-channel PWM processing circuit 106 and a dual-channel overcurrent protection circuit 101. The dual-channel overcurrent protection circuit 101 is used to sample the operating current of the load 105 in two channels to obtain a current feedback signal, and transmits the current feedback signal to the dual-channel volume control BUCK circuit 103. The dual-channel volume control BUCK circuit 103 then transmits the current feedback signal to the dual-channel PWM processing circuit 106. The dual-channel PWM processing circuit 106 is used to receive the current feedback signal and control the output of the dual-channel volume control BUCK circuit 103 according to the current feedback signal. The dual-channel PWM processing circuit 106 can also be used to sample the operating voltage of the load 105 in two channels to obtain a voltage feedback signal, and control the output of the dual-channel volume control BUCK circuit 103 according to the voltage feedback signal.

[0024] The dual-channel volume control BUCK circuit 103 further includes two sampling comparison circuits. The two sampling comparison circuits are used to divide and sample the adjustable power amplifier voltages output by the two BUCK circuits to obtain two sampled voltages. The two sampled voltages are then compared with a reference comparison voltage, and two error comparison signals are output to the dual-channel PWM processing circuit 106. The dual-channel PWM processing circuit 106 is used to receive the two error comparison signals and output two control signals to the two BUCK circuits to adjust the adjustable power amplifier voltages output by the two BUCK circuits.

[0025] like Figure 4 As shown, the dual-channel volume control BUCK circuit 103 includes an internal power supply module, two BUCK circuits and their driving circuits, two sampling comparison circuits, and one power protection circuit. The internal power supply module transforms the DC reference power supply to obtain the internal power supply, and transmits the internal power supply to the dual-channel PWM processing circuit 106 to power the dual-channel PWM processing circuit 106. Wherein: In the internal power supply module: U1 is a small DC / DC switching power supply module. It receives a voltage (+44V) from point M2. Its output 12V voltage is filtered by C3, L1, C2, and C1, and then outputs a stable 12V voltage from port D1 to power the PWM chip.

[0026] The two-channel BUCK circuit includes: 1. Positive BUCK circuit. The positive voltage (+44V) input from port IO5 is low-pass filtered by circuits L3 and C13 for high-frequency anti-interference isolation, and then sent to the Q2 switching transistor for chopping control. L2 is an energy storage inductor, D1A is a freewheeling diode, and C7 and C8 are the high and low frequency filter capacitors at the voltage output terminal, respectively. Finally, an adjustable positive voltage of + (8V~44V) is output from port IO18. 2. Negative BUCK circuit. The negative voltage (-44V) input from port IO6 is low-pass filtered by circuits L6 and C18 for high-frequency anti-interference isolation, and then sent to the Q3 switching transistor for chopping control. L5 is an energy storage inductor, D7A is a freewheeling diode, and C20 and C21 are the high and low frequency filter capacitors at the voltage output terminal, respectively. Finally, an adjustable negative voltage of - (8V~44V) is output from port IO19.

[0027] The 12V voltage at port D1 is current-limited and regulated by R16, D6, and C14, resulting in a stable 5.1V voltage across D6. This voltage powers the series resistors R17 and R14. R14 is a lower voltage limit resistor, ensuring the output voltage is at least 6V. R17 is a potentiometer used to generate an equivalent audio voltage signal. Adjusting R17 allows for an output voltage of 1-5V at its sliding contact. To improve anti-interference capability, this voltage is filtered through L4 and C12, as well as R18, C15, and C16, and then used as a reference comparison voltage (the voltage at point M22) to supply pins 2 of comparators U2A and U4A respectively.

[0028] For the two-channel sampling and comparison circuit: the output from the IO18 port is the positive voltage of the power amplifier. This voltage is divided by R4 and R5 to obtain a positive terminal sampling voltage at point M8, which is sent to pin 3 of U2A. After comparing the positive terminal sampling voltage with the equivalent audio voltage signal (reference comparison voltage) at pin 2 of U2A, a positive terminal error comparison signal is output from pin 1 of U2A. This signal is then divided by R7 and R6 and output from the A51 port to the dual-channel PWM processing circuit for processing, which is used to adjust the voltage of the power amplifier's positive power supply within a large range. The output from IO19 port is the power amplifier's negative voltage. This voltage is divided by R23 and R24, resulting in a negative terminal sampling voltage at point N8. This negative terminal sampling voltage is inverted by an inverter composed of R22, R20, U4B, and R13 and transmitted to pin 3 of U4A. It is then compared with the equivalent audio voltage signal (reference comparison voltage) at pin 2 of U4A, and a negative terminal error comparison signal is output from pin 1 of U4A. This signal is then divided by R19 and R21 and output from port A61, where it is sent to the dual-channel PWM processing circuit for processing. This circuit is used to adjust the power amplifier's negative power supply voltage within a wide range.

[0029] Considering that the BUCK circuit is a step-down circuit and the switching transistor has a voltage drop of nearly 2V when saturated, the maximum output voltage of the BUCK circuit when operating at its maximum duty cycle is 33V, which cannot reach 44V. To improve the output voltage and power supply efficiency, the maximum power amplifier voltage is considered to be connected to the circuit, as shown in the figure. Figure 4As shown, U2B is a Schmitt trigger. Pin 6 of U2B receives a 4.7V reference voltage (voltage at point M21). When the equivalent audio voltage signal at point M20 is less than the reference voltage at point M21, pin 7 of U2B outputs a low level, Q1 is cut off, relay K1 does not work, and the normal voltage regulation operation of the BUCK circuit is not affected. When the equivalent audio voltage signal at point M20 is greater than the reference voltage at point M21, pin 7 of U2B outputs a high level, Q1 is saturated and conducts, relay K1 works, and its two sets of normally open contacts conduct. One set of contacts shorts M2 and M5, and the IO18 port outputs a +44V voltage. At the same time, the corresponding BUCK circuit stops working. The other set of contacts also shorts N2 and N5, and the IO19 port outputs a -44V voltage. At the same time, the corresponding BUCK circuit stops working.

[0030] For the power protection circuit: The power protection circuit can control the output of the internal power module according to the current feedback signal. When the load is overcurrent or short-circuited, the dual overcurrent protection circuit will operate, pull the potential of the A7 port down (below 4.7V), so that the K1 relay is de-energized and does not work, ensuring that the power supply does not short-circuit through K1, thereby protecting the power supply.

[0031] like Figure 3 As shown, the dual-channel PWM processing circuit 106 includes two UC3842 type PWM processors. The positive error signal from the dual-channel volume control BUCK circuit 103 is sent to pin 2 of U10 via port A51. After PWM processing, it is output from pin 6 of U10 and then sent to pin 2 of the optocoupler driver U3 of the dual-channel volume control BUCK circuit 103 via port A53. After isolation and driving by U3, it controls the switching transistor Q2 for chopping. The negative error signal from the dual-channel volume control BUCK circuit 103 is sent to pin 2 of U11 via port A61. After PWM processing, it is output from pin 6 of U11 and then sent to pin 2 of the optocoupler driver U5 of the dual-channel volume control BUCK circuit 103 via port A63. After isolation and driving by U5, it controls the switching transistor Q3 for chopping. When an overcurrent or short-circuit fault occurs in the load, a stable high-level signal is sent from the dual-channel overcurrent protection circuit 101 and simultaneously sent to pin 3 of U10 and U11 through the A71 port, forcing U10 and U11 to stop working. Consequently, the dual-channel BUCK circuit also stops working, and the power amplifier voltage drops to zero.

[0032] like Figure 5As shown, the dual-channel overcurrent protection circuit 101 includes two overcurrent protection processing circuits centered around photosensitive thyristors U12 and U13. These circuits process the load overcurrent sampling signal or short-circuit current signal (current feedback signal) from the linear power supply module 104, triggering latching and outputting an overcurrent protection signal to the dual-channel tone-controlled BUCK circuit 103 for overcurrent or short-circuit protection of the entire power supply. When the power supply is operating normally, the load current is normal, and the sampling voltages fed back from ports A3, A4, or A5, A6 are small and insufficient to trigger the photosensitive thyristors U12 or U13 to conduct. The low-level output from port IO12 (or port A71) is sent to pin 3 of U10 and U11 in the dual-channel PWM processing circuit 106, without affecting the normal operation of U10 and U11. When any load of the power amplifier power supply experiences an overcurrent or short circuit, a sampling voltage will be fed back from ports A3, A4, or A5, A6, becoming high enough to trigger the conduction of the optical thyristor U12 or U13. This will output a locked high level from port IO12 (or port A71), which will be sent to pin 3 of U10 and U11 in the dual-channel PWM processing circuit 106 to control U10 and U11 to stop outputting PWM signals, forcing the dual-channel BUCK circuit to stop working, thereby making the power amplifier voltage output from ports IO18 and IO19 0V.

[0033] like Figure 6 As shown, the linear power supply module 104 includes two low-dropout linear power supply circuits and two 39V power amplifier preamplifier voltages with simple voltage regulation. The linear power supply module 104 is used to provide the power amplifier main voltage with low ripple and low interference to the load 105. Among them, R34, C53 and R39, C64 form two load overcurrent sampling circuits, which are used to sample the current for overcurrent protection or short circuit protection of the entire power supply. The power amplifier positive voltage + (8V-44V) from the dual-channel volume control BUCK circuit 103 is input from the IO18 port. This voltage has large ripple and high-frequency interference signals. This voltage is divided into two paths. One path is filtered by two stages of low-pass filtering through L11, C58, R36, and C57 to obtain a more stable DC voltage, which is applied to the base of the Darlington transistor Q4 as a control signal. The other path is applied to the collector of Q4. After being amplified by the current of Q4, the low-ripple and low-interference purified power amplifier positive voltage is output from the emitter of Q4. The process of obtaining the negative voltage of the purification power amplifier is similar to that of obtaining the positive voltage of the purification power amplifier.

[0034] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A volume-controlled BUCK amplifier power supply with linear power module output, characterized in that, The system includes a power amplifier transformer module (102), a dual-channel volume control BUCK circuit (103), and a linear power supply module (104). The power amplifier transformer module (102) is used to connect to an external power supply and to transform and rectify the external power supply, outputting two independent DC drive power supplies and two independent DC reference power supplies to the dual-channel volume control BUCK circuit (103). The dual-channel volume control BUCK circuit (103) contains two BUCK circuits. The two independent DC drive power supplies are used to drive the two BUCK circuits in the dual-channel volume control BUCK circuit (103) to operate. The equivalent audio voltage signal control is applied to the two independent DC reference power supplies, and two adjustable power amplifier voltages are output to the linear power supply module (104). The dual-channel sound control BUCK circuit (103) is also used to transmit the two independent DC reference power supplies to the linear power supply module (104). The linear power supply module (104) is used to perform low-pass filtering and active amplification on the two adjustable power amplifier voltages to obtain two purified power amplifier voltages, to perform voltage regulation on the two independent DC reference power supplies to obtain two power amplifier preamplifier power supplies, and to output the two purified power amplifier voltages and the two power amplifier preamplifier power supplies to the external load (105).

2. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 1, characterized in that, It also includes a dual-channel PWM processing circuit (106). The dual-channel volume control BUCK circuit (103) further includes two sampling comparison circuits. The two sampling comparison circuits are used to divide and sample the adjustable power amplifier voltages output by the two BUCK circuits to obtain two sample voltages. The two sample voltages are compared with the reference comparison voltage, and two error comparison signals are output to the dual-channel PWM processing circuit (106). The dual-channel PWM processing circuit (106) is used to receive the two error comparison signals and output two control signals to the two BUCK circuits to adjust the adjustable power amplifier voltages output by the two BUCK circuits.

3. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 2, characterized in that, It also includes a dual-channel overcurrent protection circuit (101), which is used to sample the load (105) with dual-channel operating current to obtain a current feedback signal and transmit the current feedback signal to a dual-channel sound control BUCK circuit (103). The dual-channel sound control BUCK circuit (103) transmits the current feedback signal to a dual-channel PWM processing circuit (106), which is used to receive the current feedback signal and control the output of the dual-channel sound control BUCK circuit (103) according to the current feedback signal.

4. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 3, characterized in that, The dual-channel sound control BUCK circuit (103) also includes an internal power supply module, which is used to transform the DC reference power supply to obtain an internal power supply and transmit the internal power supply to the dual-channel PWM processing circuit (106) to power the dual-channel PWM processing circuit (106).

5. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 4, characterized in that, The dual-channel volume control BUCK circuit (103) also includes a power protection circuit, which controls the output of the internal power module according to the current feedback signal.

6. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 2, characterized in that, The dual-channel PWM processing circuit (106) is also used to sample the load (105) with dual-channel operating voltage to obtain a voltage feedback signal, and control the output of the dual-channel volume control BUCK circuit (103) according to the voltage feedback signal.

7. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 2, characterized in that, The dual-channel PWM processing circuit (106) includes two UC3842 type PWM processing processors.

8. The power supply for a volume-controlled BUCK amplifier outputting a linear power module according to claim 1, characterized in that, The power amplifier transformer module (102) includes multiple sets of transformer windings and a bridge rectifier circuit, which are used to transform and rectify the external power supply, respectively.

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