A power amplifier power supply circuit with enhanced instantaneous drive capability under weak power supply

Abstract

This invention discloses a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions, applicable to power amplifiers with adjustable power rail voltage powered by a USB interface power supply or other low-power power supplies. It includes a signal processing unit and a boost power supply unit. The input terminal of the signal processing unit is connected to the audio signal input, and after processing the audio signal, it is connected to the input terminal of the power amplifier and the feedback terminal of the boost power supply unit. The input terminal of the boost power supply unit is connected to an external weak power supply, and the feedback terminal is connected to one of the outputs of the signal processing unit, with the output connected to the power supply terminal of the power amplifier. Each stage of the power supply circuit described in this invention employs a synchronous rectification boost circuit, reducing losses on the rectifier diodes and increasing the energy storage capacity of the energy storage devices. Through stage-by-stage energy storage and dynamic boosting, it can meet the driving requirements of audio signals with a wide envelope and containing instantaneous high-power signals, and is suitable for power amplifiers with different voltage supply requirements.

Description

Technical Field

[0001] This invention relates to the field of electronic circuits, and more specifically to a power amplifier power supply circuit that enhances instantaneous driving capability under weak power conditions. Background Technology

[0002] Most of the time, the power required to play audio is relatively small. However, to handle the potential for sudden high-power signals in audio, amplifier systems typically use power supplies with higher power than actually needed, which means unavoidable power loss. This problem is particularly prominent in applications that are frequently used, such as vending machines and game consoles. These applications, in order to save energy and improve efficiency, usually design power supplies based on average power consumption, using low-power power supplies with weak driving capabilities connected via USB interfaces. Therefore, while efficiency is improved, the ability to drive some of the high-power signals in audio is sacrificed.

[0003] Therefore, it is necessary to provide a power amplifier power supply circuit that can both ensure efficiency and instantly improve driving capability. Summary of the Invention

[0004] The technical problem to be solved by this invention is how to improve the driving capability of a power amplifier under instantaneous high-power signals when using a low-power power supply, in order to ensure power supply efficiency.

[0005] To address this issue, the present invention provides a power amplifier power supply circuit for enhancing instantaneous drive capability under weak power conditions, applicable to power amplifiers with adjustable power rail voltage powered by a USB interface power supply or other low-power power supplies. It includes a signal processing unit and a boost power supply unit. The input terminal of the signal processing unit is connected to an audio signal input, and after processing the audio signal, it is connected to the input terminal of the power amplifier and the feedback terminal of the boost power supply unit. The input terminal of the boost power supply unit is connected to an external weak power supply, and the feedback terminal is connected to one of the outputs of the signal processing unit, with the output connected to the power supply terminal of the power amplifier.

[0006] The signal processing unit is used to perform envelope detection, delay processing, and gain adjustment on the input audio signal. The input terminal of the signal processing unit is connected to the audio signal input, the control terminal is connected to the boost power supply unit, and the output terminal is connected to the input terminal of the power amplifier.

[0007] The boost power supply unit is used for storing and regulating excess energy, including an energy storage boost circuit and a dynamic boost circuit. The energy storage boost circuit is a boost topology, using synchronous rectification. The energy storage device is a supercapacitor. Switch 1 is controlled to turn on and off by a square wave output from control module 1 and drive circuit 1. The circuit input is connected to an external low-voltage power supply. One input of control module 1 is connected to the output of the energy storage boost circuit, and the other input is connected to the external low-voltage power supply. One output is connected to the input of drive circuit 1, and the other output is connected to the control terminal of the signal processing unit. Control module 1 detects the power supply status of the external low-voltage power supply. When the power supply voltage / current drops below a preset voltage / current 1, the current limit value is reduced, and drive circuit 1 adjusts the drive waveform of switch 1 according to the current limit value. When the power supply voltage / current is greater than or equal to the preset voltage / current 1, the default current limit value is maintained. Control module 1 also detects the output voltage of the energy storage boost circuit, i.e., the energy storage voltage of the supercapacitor. When the energy storage voltage is lower than a preset voltage 2, the gain of the audio signal is reduced through the signal processing unit connected to the output. The dynamic boost circuit is a boost topology, employing synchronous rectification. Its input is connected to the output of the energy storage boost circuit. Switch 2 is controlled by a square wave output from the control module 2 and the drive circuit 2, and its output is connected to the power amplifier's power supply. The control module 2 adjusts the drive waveform generated by the drive circuit 2 based on the envelope of the audio signal detected by the signal processing unit and the output voltage of the dynamic boost circuit. When the envelope of the audio signal increases, the control module 2 determines whether the output voltage of the dynamic boost circuit can meet the power supply requirements. If it can, the drive waveform remains unchanged; otherwise, the drive waveform is adjusted to increase the duty cycle.

[0008] Preferably, when the power amplifier requires a high supply voltage, the boost power supply unit can adopt a two-stage series topology. The first-stage boost power supply unit includes a first-stage energy storage boost circuit and a first-stage dynamic boost circuit, and the second-stage boost power supply unit includes a second-stage energy storage boost circuit and a second-stage dynamic boost circuit. The topology of the first-stage energy storage boost circuit is the same as that of the energy storage boost circuit. The first-stage dynamic boost circuit is a boost topology, using synchronous rectification. Its input is connected to the output of the first-stage energy storage boost circuit. The switching transistor 2' is controlled by a square wave output from the driving circuit 2', which generates a fixed driving waveform. Its output is connected to the input of the second-stage boost power supply unit. The topology of the second-stage energy storage boost circuit is the same as that of the energy storage boost circuit. Its input is connected to the output of the first-stage dynamic boost circuit, and its output is connected to the input of the second-stage dynamic boost circuit. The topology of the second-stage dynamic boost circuit is the same as that of the dynamic boost circuit.

[0009] Preferably, when the power amplifier requires a high supply voltage, the boost power supply unit can adopt a multi-stage series topology, that is, an intermediate-stage boost power supply unit is added between the two-stage series topologies. The intermediate-stage boost power supply unit includes a combination of N intermediate-stage energy storage boost circuits and intermediate-stage dynamic boost circuits, and each combination has the same topology as the first-stage boost power supply unit; wherein the input of the first intermediate-stage energy storage boost circuit is connected to the output of the first-stage boost power supply unit, and the inputs of the remaining intermediate-stage energy storage boost circuits are all connected to the output of the previous intermediate-stage dynamic boost circuit; wherein the output of the last intermediate-stage dynamic boost circuit is connected to the input of the second-stage boost power supply unit, and the outputs of the remaining intermediate-stage dynamic boost circuits are all connected to the input of the next intermediate-stage energy storage boost circuit.

[0010] This invention discloses a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions. It employs a dynamic power supply circuit, effectively reducing system power consumption and improving efficiency. Each stage of the power supply circuit uses a synchronous rectification and boost circuit, reducing losses in the rectifier diodes and increasing the energy storage capacity of the energy storage devices. Through stage-by-stage energy storage and dynamic boosting, it can meet the driving requirements of audio signals with a wide envelope and containing instantaneous high-power signals, and is suitable for power amplifiers with different voltage requirements.

[0011] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a combined block diagram of a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions, as described in this invention.

[0014] Figure 2 This is a schematic block diagram of the first embodiment of a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions according to the present invention.

[0015] Figure 3 This is a schematic block diagram of a second embodiment of a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions according to the present invention.

[0016] 10, 10': Signal processing unit; 20, 20': Boost power supply unit; 30, 30': Power amplifier;

[0017] 101, 101': Envelope detection module; 102, 102': Delay processing module;

[0018] 103, 103': Gain adjustment module;

[0019] 201', 20A1, 20B1: Energy storage boost circuit; 202', 20A2, 20B2: Dynamic boost circuit;

[0020] 2011, 20A11, 20B11: Control module 1; 2012, 20A12, 20B12: Drive circuit 1;

[0021] 2021, 20A21, 20B21: Control module 2; 2022, 20A22, 20B22: Drive circuit 2;

[0022] T1, T1A, T1B: Switch 1; T2, T2A, T2B: Switch 2; C1, C1A, C1B: Supercapacitor. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0024] Please see Figure 1 This is a block diagram illustrating the principle of a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions, as described in this invention. It includes a signal processing unit 10 and a boost power supply unit 20. The input terminal of the signal processing unit 10 is connected to an audio signal input. After processing the audio signal in different ways, it is connected to the input terminal of the power amplifier 30 and the feedback terminal of the boost power supply unit 20. The input terminal of the boost power supply unit 20 is connected to an external weak power source, and its feedback terminal is connected to one of the outputs of the signal processing unit 10. The output is connected to the power supply terminal of the power amplifier 30.

[0025] Please see Figure 2This is a schematic block diagram of a first embodiment of a power amplifier power supply circuit for enhancing instantaneous driving capability under weak power conditions, as described in this invention. It includes a signal processing unit 10' and a boost power supply unit 20'. In this embodiment, the external weak power supply Vs is a 5V, 500mA power supply, and the power amplifier 30' requires a 12V supply voltage. The signal processing unit 10' includes an envelope detection module 101', a delay processing module 102', and a gain adjustment module 103'. Its input terminals are connected to audio signal inputs VLIN and VRIN, and its control terminal is connected to one output terminal of the control module 1 in the boost power supply unit 20'. The output terminal is connected to the input terminal of the power amplifier 30'. The boost power supply unit 20' includes an energy storage boost circuit 201' and a dynamic boost circuit 202'. The energy storage boost circuit 201' is a boost topology, using synchronous rectification. The energy storage device is a supercapacitor C1. Switch 1 (T1) is controlled to turn on and off by the square wave output from control module 1 (2011) and drive circuit 1 (2012). Its input is connected to an external low-voltage power supply Vs. One input of control module 1 (2011) is connected to the output of energy storage boost circuit 201', and the other input is connected to the external low-voltage power supply Vs. One output is connected to the input of drive circuit 1 (2012), and the other output is connected to the control terminal of signal processing unit 10'. The dynamic boost circuit 202' is a boost topology, using synchronous rectification. Its input is connected to the output of energy storage boost circuit 201'. Switch 2 (T2) is controlled to turn on and off by the square wave output from control module 2 (2021) and drive circuit 2 (2022). Its output is connected to the power supply terminal of power amplifier 30'. Control module 1 (2011) detects the current of Vs. When the current is below 500mA, it reduces the current limit value Iset. Drive circuit 1 (2012) adjusts the drive waveform of switch 1 (T1) according to the current limit value Iset. When the current of Vs is 500mA, it maintains the default current limit value. Control module 1 (2011) also detects the output voltage of energy storage boost circuit 201', i.e., the energy storage voltage of supercapacitor C1. When the energy storage voltage is below 6V, it reduces the gain of the audio signal through gain adjustment module 103' connected to the output terminal. The control module 2 (2021) determines and adjusts the driving waveform generated by the driving circuit 2 (2022) based on the envelope of the audio signal detected by the envelope detection circuit 101' and the output voltage of the dynamic boost circuit 202'. When the envelope of the audio signal increases, the control module 2 (2021) determines whether the output voltage of the dynamic boost circuit 202' can meet the 12V power supply of the power amplifier 30'. If it can, the driving waveform remains unchanged; if it cannot, the driving waveform is adjusted to increase the duty cycle.

[0026] Please see Figure 3This is a schematic block diagram of a second embodiment of a power amplifier power supply circuit for enhancing instantaneous drive capability under weak power conditions, as described in this invention. In this embodiment, the external weak power supply Vs is a 5V, 500mA power supply, and the power amplifier 30''s supply voltage is 24V. The boost power supply unit 20'' adopts a two-stage series topology. The first-stage boost power supply unit 20A includes a first-stage energy storage boost circuit 20A1 and a first-stage dynamic boost circuit 20A2, boosting the voltage to 12V. The second-stage boost power supply unit includes a second-stage energy storage boost circuit 20B1 and a second-stage dynamic boost circuit 20B2, boosting the voltage to 24V. The topology of the first-stage energy storage boost circuit 20A1 is similar to... Figure 2 The topology of the energy storage boost circuit 201' is the same; the first-stage dynamic boost circuit 20A2 is a boost topology, using synchronous rectification. Its input is connected to the output of the first-stage energy storage boost circuit 20A1. The switching transistor 2' (T2A) is controlled by the square wave output from the driver circuit 2 (20A22), and its output is connected to the input of the second-stage boost power supply unit 20B. The driver circuit 2' (20A22) generates a fixed driving waveform. The topology of the second-stage energy storage boost circuit 20B1 is the same as that of 20A1. Its input is connected to the output of the first-stage dynamic boost circuit 20A2, and its output is connected to the input of the second-stage energy storage boost circuit 20B1; the topology of the second-stage dynamic boost circuit is the same as that of 20A1. Figure 2The dynamic boost circuit 202' has the same topology as the dynamic boost circuit. Control module 1 (20A11) in 20A1 detects the current in Vs. When the current is below 500mA, it lowers the current limit value Iset, and drive circuit 1 (20A12) adjusts the drive waveform of switching transistor 1 (T1A) according to the current limit value Iset. When the current in Vs is 500mA, the default current limit value is maintained. Control module 1 (20A11) in 20A1 also detects the output voltage of 20A1, i.e., the energy storage voltage of supercapacitor C1A. When the energy storage voltage is below 6V, the gain of the audio signal is reduced through the gain adjustment module 103 connected to the output terminal. The control module 1 (20B11) in 20B1 detects the output voltage of 20A. When the voltage is lower than 12V, it reduces the current limit value Iset', and the drive circuit 1 (20B12) adjusts the drive waveform of the switching transistor 1 (T1B) according to the current limit value Iset'. When the voltage is 12V, the default current limit value is maintained. The control module 1 (20B11) of 20B1 also detects the output voltage of 20B1, that is, the energy storage voltage of the supercapacitor C1B. When the energy storage voltage is lower than 12V, the gain of the audio signal is reduced through the gain adjustment module 103 connected to the output terminal. The 20B2 control module 2 (20B21) determines and adjusts the driving waveform generated by the driving circuit 2 (20B22) based on the envelope of the audio signal detected by the envelope detection circuit 101 and the output voltage of the dynamic boost circuit 20B2. When the envelope of the audio signal increases, the control module 2 (20B21) determines whether the output voltage of the dynamic boost circuit 20B2 can meet the 24V power supply of the power amplifier 30. If it can, the driving waveform remains unchanged; if it cannot, the driving waveform is adjusted to increase the duty cycle.

[0027] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A power amplifier power supply circuit for enhancing instantaneous drive capability under weak power conditions, characterized in that, It includes a signal processing unit and a boost power supply unit; the input terminal of the signal processing unit is connected to the audio signal input, and after processing the audio signal, it is connected to the input terminal of the power amplifier and the feedback terminal of the boost power supply unit respectively; the input terminal of the boost power supply unit is connected to an external low power supply, the feedback terminal is connected to one of the outputs of the signal processing unit, and the output is connected to the power supply terminal of the power amplifier; The signal processing unit includes an envelope detection module, a delay processing module, and a gain adjustment module; the input terminal is connected to the audio signal input, the control terminal is connected to the boost power supply unit, and the output terminal is connected to the input terminal of the power amplifier. The boost power supply unit includes an energy storage boost circuit and a dynamic boost circuit. The energy storage boost circuit is a boost topology, uses synchronous rectification, and its input is connected to an external low-voltage power supply. The energy storage device is a supercapacitor. The switching transistor 1 is controlled by a square wave output from the control module 1 and the drive circuit 1 to turn on and off. One input of the control module 1 is connected to the output of the energy storage boost circuit, and the other input is connected to the external low-voltage power supply. One output is connected to the input of the drive circuit 1, and the other output is connected to the control terminal of the signal processing unit. The control module 1 detects the power supply status of the external weak power source. When the power supply voltage / current drops below a preset voltage / current 1, the current limit value is reduced, and the drive circuit 1 adjusts the drive waveform of the switching transistor 1 according to the current limit value. When the power supply voltage / current is greater than or equal to the preset voltage / current 1, the default current limit value is maintained. The control module 1 also detects the output voltage of the energy storage boost circuit, i.e., the energy storage voltage of the supercapacitor. When the energy storage voltage is lower than a preset voltage 2, the gain of the audio signal is reduced through the signal processing unit connected to the output terminal. The dynamic boost circuit is a boost topology. Using synchronous rectification, the input terminal is connected to the output terminal of the energy storage boost circuit. The switching transistor 2 is controlled to turn on and off by the square wave output by the control module 2 and the drive circuit 2. The output terminal is connected to the power supply terminal of the power amplifier. The control module 2 judges and adjusts the drive waveform generated by the drive circuit 2 based on the envelope of the audio signal detected by the signal processing unit and the output voltage of the dynamic boost circuit. When the envelope of the audio signal increases, the control module 2 judges whether the output voltage of the dynamic boost circuit can meet the power supply requirements. If it can, the drive waveform remains unchanged; if it cannot, the drive waveform is adjusted.

2. The power amplifier power supply circuit for enhancing instantaneous drive capability under weak power supply conditions as described in claim 1, characterized in that, The boost power supply unit adopts a multi-stage series topology, including a first-stage boost power supply unit, a final-stage boost power supply unit, and an intermediate-stage boost power supply unit; The first-stage boost power supply unit includes a first-stage energy storage boost circuit and a first-stage dynamic boost circuit. The topology of the first-stage energy storage boost circuit is the same as that of the energy storage boost circuit. The first-stage dynamic boost circuit is a boost topology and uses synchronous rectification. Its input terminal is connected to the output terminal of the first-stage energy storage boost circuit. The switching transistor 2' is controlled to be turned on and off by the square wave output by the driving circuit 2'. The driving circuit 2' generates a fixed driving waveform, and its output terminal is connected to the input terminal of the intermediate-stage boost power supply unit. The final-stage boost power supply unit includes a final-stage energy storage boost circuit and a final-stage dynamic boost circuit; the topology of the final-stage energy storage boost circuit is the same as that of the energy storage boost circuit, the input terminal is connected to the output terminal of the intermediate-stage dynamic boost circuit, and the output terminal is connected to the input terminal of the final-stage dynamic boost circuit; the topology of the final-stage dynamic boost circuit is the same as that of the dynamic boost circuit. The intermediate-stage boost power supply unit includes N combinations of intermediate-stage energy storage boost circuits and intermediate-stage dynamic boost circuits, and each combination has the same topology as the first-stage boost power supply unit. The input of the first intermediate-stage energy storage boost circuit is connected to the output of the first-stage boost power supply unit, and the inputs of the remaining intermediate-stage energy storage boost circuits are all connected to the output of the previous intermediate-stage dynamic boost circuit. The output of the last intermediate-stage dynamic boost circuit is connected to the input of the last-stage boost power supply unit, and the outputs of the remaining intermediate-stage dynamic boost circuits are all connected to the input of the next intermediate-stage energy storage boost circuit.

Images