Half-bridge low-resistance signal amplification circuit
By adopting half-bridge low-resistance signal amplification circuit and high-frequency PWM carrier signal technology in vehicle audio systems, the problems of low efficiency and energy loss of traditional circuits under low voltage conditions are solved, and efficient audio signal amplification and resistance are achieved Interference capability extends the life of the equipment.
Patent Information
- Application Number
- CN202421049595.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-15
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-05-15
AI Technical Summary
Traditional vehicle audio signal amplification circuit is inefficient under low voltage conditions, resulting in high boost cost and large energy loss, making it difficult to achieve efficient audio signal amplification.
The audio signal is loaded on the PWM carrier signal signal through the high-frequency PWM carrier signal technology. The high-efficiency energy conversion characteristics of the PWM signal are used, and the PWM positive control is finely controlled by combining the ALC gain control and power management circuit. Half-wave and negative half-wave improve amplification efficiency and anti-interference ability.
It reduces the boost cost and energy loss, improves the efficiency of converting low voltage to high voltage, enhances the amplification efficiency and anti-interference ability of audio signals, reduces heat generation, and extends the service life of the equipment.
Smart Images
Figure CN222339364U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of sound systems, in particular to a half-bridge low-resistance signal amplifying circuit. Background Art
[0002] The traditional sound system amplifies the weak audio signal and drives the traditional speaker unit to make sound. However, in battery-powered mobile systems or vehicle-mounted systems, since their power supply voltage is limited, if you want to get a better sound effect experience, you need to provide a larger output power. Due to the voltage limitation, if you want to get more power, you must boost the existing voltage through a boost circuit and supply it to a high-power amplifier circuit. This means that the cost of the expensive boost circuit needs to be increased. Traditional vehicle-mounted audio signal amplification circuits usually use linear amplification technology, which means that the amplifier consumes a lot of energy when amplifying the signal, but only a small part of the energy is converted into audio output, and most of the remaining energy is dissipated in the form of heat, resulting in low conversion efficiency. For this reason, the present application proposes a half-bridge low-impedance signal amplifier circuit. Utility Model Content
[0003] In order to solve the above problems, the utility model provides a half-bridge low-resistance signal amplification circuit. The utility model can reduce the boosting cost and energy loss, and improve the efficiency of converting low voltage to high voltage.
[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0005] A half-bridge low-resistance signal amplifier circuit includes a signal processing module, the signal processing module includes a signal amplifier circuit and a high-frequency PWM carrier signal circuit, the high-frequency PWM carrier signal circuit includes a PWM positive half-wave amplifier circuit, a PWM negative half-wave amplifier circuit and a carrier signal modulator. The first output end of the signal amplifier circuit is electrically connected to the carrier signal modulator, the first output end of the carrier signal modulator is electrically connected to the PWM positive half-wave amplifier circuit, and the second output end of the carrier signal modulator is electrically connected to the PWM negative half-wave amplifier circuit.
[0006] Preferably, the signal processing module also includes an ALC gain control circuit and a power management circuit, the output end of the ALC gain control circuit is electrically connected to the input end of the power management circuit, the first output end of the power management circuit is electrically connected to the high-frequency PWM carrier signal circuit, and the second output end of the power management circuit is electrically connected to the carrier signal modulator via a clock signal generator.
[0007] Preferably, the output end of the signal amplifying circuit is electrically connected to the input end of the ALC gain control circuit via a first resistor and a diode a.
[0008] Preferably, it also includes a gate driving circuit, and the output end of the PWM positive half-wave amplifier circuit and the output end of the PWM negative half-wave amplifier circuit are electrically connected to the gate driving circuit respectively, and each of the gate driving circuits includes a voltage stabilizing circuit and an anti-dead zone correction circuit; the input end of one of the voltage stabilizing circuits is electrically connected to the third output end of the power management circuit, and the first output end of the voltage stabilizing circuit is electrically connected to the input end of the anti-dead zone correction circuit.
[0009] Preferably, the gate drive circuit also includes a bootstrap circuit, a first input terminal of the bootstrap circuit is electrically connected to the PWM positive half-wave amplifier circuit or the PWM negative half-wave amplifier circuit, and a second input terminal of one of the bootstrap circuits is electrically connected to the second output terminal of the voltage stabilizing circuit through a diode b.
[0010] Preferably, the gate drive circuit also includes a MOS drive circuit, which includes a first MOS power tube and a second MOS power tube, and the drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the output end of the bootstrap circuit through a first capacitor.
[0011] Preferably, the source of the first MOS power tube is grounded, and the drain of the second MOS power tube is electrically connected to a power supply.
[0012] Preferably, an LC filter module is further included, and the drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the LC filter module.
[0013] Preferably, the LC filter module includes an inductor, a second capacitor, a third capacitor and a second resistor. The drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the load through the inductor, and the drain of the first MOS power tube is grounded through the inductor and the second capacitor in sequence; the source of the second MOS power tube is grounded through the inductor, the second resistor and the third capacitor in sequence.
[0014] Preferably, the third output terminal of the voltage stabilizing circuit is electrically connected to the gate of the first MOS power tube through an operational amplifier.
[0015] The beneficial effects of the utility model are:
[0016] 1. After the audio signal is amplified and processed, it is loaded on the high-frequency PWM carrier signal. The PWM signal can control the voltage and current in the circuit by changing the width of the pulse, thereby achieving efficient energy conversion. After the audio signal is loaded on the PWM carrier signal, the efficient energy conversion characteristics of the PWM signal can be used to improve the amplification efficiency of the audio signal and reduce energy loss. It has low static power consumption and strong driving ability. It can easily drive low-resistance and high-power loads under very low power supply voltage conditions. The PWM signal is a digital signal, and its anti-interference ability is stronger than that of the analog signal. Therefore, loading the audio signal on the PWM carrier signal can improve the anti-interference ability of the audio signal to a certain extent and reduce the impact of external noise on the audio signal.
[0017] 2. By controlling the positive and negative half-waves of PWM separately, the waveform of the audio signal can be adjusted more accurately and distortion can be reduced. This fine control helps to maintain the original characteristics of the audio signal and improve fidelity. In power amplification applications, independent control of the positive and negative half-waves of PWM allows for more efficient use of power, thereby improving power amplification efficiency. Because the PWM signal is a digital signal, it can more accurately control the waveforms of current and voltage, thereby more efficiently converting electrical energy into audio energy. In the power amplification process, heat is a problem that needs to be paid attention to. By controlling the positive and negative half-waves of PWM, unnecessary energy loss can be reduced, thereby reducing heat generation and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a block diagram of a half-bridge low-impedance signal amplification circuit in a specific embodiment of the utility model. DETAILED DESCRIPTION
[0019] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. Several embodiments of the utility model are given in the accompanying drawings. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein.
[0020] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installed", "connected", "electrically connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed electrical connection, a detachable electrical connection, or an integral electrical connection; it can be a mechanical electrical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances. The terms "a", "b", "first", and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.
[0021] The utility model is described in detail below in conjunction with the accompanying drawings and embodiments.
[0022] Example 1
[0023] A half-bridge low-resistance signal amplification circuit comprises a signal processing module, wherein the signal processing module comprises a signal amplification circuit and a high-frequency PWM carrier signal circuit, wherein the high-frequency PWM carrier signal circuit comprises a PWM positive half-wave amplification circuit, a PWM negative half-wave amplification circuit and a carrier signal modulator.
[0024] In practical applications, the signal amplifier circuit is used to receive an analog audio signal and amplify the analog audio signal, and the amplified analog audio signal is transmitted to the high-frequency PWM carrier signal circuit. The first output end of the signal amplifier circuit is electrically connected to the carrier signal modulator, the first output end of the carrier signal modulator is electrically connected to the PWM positive half-wave amplifier circuit, and the second output end of the carrier signal modulator is electrically connected to the PWM negative half-wave amplifier circuit. This application adopts the PWM carrier technology with a switching frequency of up to 500KHz to load the audio signal on the high-frequency carrier signal to achieve power amplification.
[0025] The present application is also provided with an ALC gain control circuit and a power management circuit. The ALC gain control circuit is used to automatically adjust the gain of the amplifier circuit when the input signal level changes to maintain the stability of the output signal level. The power management circuit is used to control, regulate and monitor the electronic circuit of the power supply, aiming to ensure that the device can obtain a stable and reliable power supply under various working conditions.
[0026] The output end of the ALC gain control circuit is electrically connected to the input end of the power management circuit, the first output end of the power management circuit is electrically connected to the high-frequency PWM carrier signal circuit, the second output end of the power management circuit is electrically connected to the carrier signal modulator through a clock signal generator, and the output end of the signal amplification circuit is electrically connected to the input end of the ALC gain control circuit through a first resistor and a diode a.
[0027] The output end of the PWM positive half-wave amplifier circuit and the output end of the PWM negative half-wave amplifier circuit are respectively electrically connected to a gate drive circuit, and each of the gate drive circuits includes a voltage stabilization circuit and an anti-dead zone correction circuit. In this embodiment, the anti-dead zone correction circuit is an H-bridge anti-dead zone correction circuit, which is a specially designed circuit used to ensure that in the H-bridge drive circuit, the upper and lower switching tubes (such as MOS tubes or IGBTs) of the same bridge arm will not be turned on at the same time, thereby preventing a short circuit from occurring.
[0028] In the H-bridge drive circuit, if the upper and lower switches of the same bridge arm are turned on at the same time, it will cause a power short circuit, which may damage the circuit components. The anti-dead zone control circuit ensures that this situation does not happen by precisely controlling the on and off timing of the switches. By avoiding unnecessary power consumption and heat generation, the anti-dead zone control circuit helps to improve the overall efficiency of the circuit and the safety of its operation.
[0029] An input terminal of one of the voltage stabilizing circuits is electrically connected to a third output terminal of the power management circuit, and a first output terminal of the voltage stabilizing circuit is electrically connected to an input terminal of the anti-dead zone correction circuit.
[0030] The gate drive circuit also includes a bootstrap circuit, which is also called a boost circuit. It is a circuit that uses electronic components such as a bootstrap boost diode and a bootstrap boost capacitor to superimpose the capacitor discharge voltage and the power supply voltage to increase the voltage. The first input end of the bootstrap circuit is electrically connected to the PWM positive half-wave amplifier circuit or the PWM negative half-wave amplifier circuit, and the second input end of one of the bootstrap circuits is electrically connected to the second output end of the voltage stabilizing circuit through a diode b.
[0031] The gate drive circuit also includes a MOS drive circuit, which includes a first MOS power tube and a second MOS power tube. The drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the output end of the bootstrap circuit through a first capacitor, the source of the first MOS power tube is grounded, and the drain of the second MOS power tube is electrically connected to a power supply. The third output end of the voltage stabilizing circuit is electrically connected to the gate of the first MOS power tube through an operational amplifier.
[0032] The MOSFET driving circuit amplifies the PWM carrier signal, and the anti-dead zone correction circuit is used to correct the duty cycle of the amplified PWM carrier signal to perform dead zone compensation and output the PWM carrier signal after the duty cycle is corrected. The corrected PWM carrier signal is power amplified by the anti-dead zone correction circuit to drive the first MOSFET power tube and / or the second MOSFET power tube. By setting the anti-dead zone correction circuit, the second MOSFET power tube / the first MOSFET power tube is kept turned off before the first MOSFET power tube / the second MOSFET power tube is completely turned off, which can avoid the device from being burned out and ensure the normal driving of the first MOSFET power tube and the second MOSFET power tube.
[0033] The present application also includes an LC filter module, and the drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the LC filter module. The LC filter module includes an inductor, a second capacitor, a third capacitor, and a second resistor. The drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the load through the inductor, and the drain of the first MOS power tube is grounded through the inductor and the second capacitor in sequence; the source of the second MOS power tube is grounded through the inductor, the second resistor, and the third capacitor in sequence.
[0034] Specifically, the LC filter module can effectively filter the PWM drive signal. After the analog audio signal passes through the PWM generation module, the audio signal is loaded on the PWM carrier signal generated by the PWM generation module, and then amplified by the PWM power drive module. The LC filter module filters out the high-frequency PWM carrier signal, leaving the amplified analog audio signal to drive the load, that is, to drive the speaker.
[0035] Example 2
[0036] The H-bridge anti-dead-zone control circuit described in Example 1 performs power amplification on the corrected PWM carrier signal, and also includes monitoring the waveform. Monitoring the waveform is part of the performance optimization process. By observing the waveform, the actual performance of the system can be understood and adjusted as needed. During the operation of the system, if any problems or abnormalities occur, the abnormal waveform is compensated and corrected to ensure stable operation of the system.
[0037] The gate drive circuit is also equipped with overheat protection and undervoltage protection. When the audio amplifier is overheated due to long-term high-load operation or other reasons during operation, the overheat protection mechanism will be activated to automatically reduce the power or completely shut down the amplifier to prevent high temperature from damaging the internal circuits and electronic components. This can effectively prevent thermal runaway and protect key components such as transistors, capacitors, inductors, etc., to prevent them from being damaged or performance degradation due to overheating.
[0038] MOS power tubes in gate drive circuits are very sensitive to voltage and temperature, and overheating and undervoltage conditions may damage them. Setting overheat protection and undervoltage protection can ensure that these key components are protected in time under abnormal conditions to avoid damage, thereby extending the service life of the entire circuit.
[0039] When an audio amplifier overheats or undervoltage occurs, without appropriate protection measures, it may cause degraded sound quality, increased noise, or complete device failure. This will not only affect the user's listening experience, but may also cause inconvenience and distress to the user. By setting overheat protection and undervoltage protection, you can ensure that the audio amplifier always works in the best condition, providing high-quality audio output, thereby improving the overall user experience.
[0040] To summarize, the present application adopts a voltage and resistance power conversion method, and uses an extremely low internal resistance power device to load the audio signal through a high-frequency carrier signal. After amplification, the carrier signal is filtered out through an LC circuit, leaving a useful audio signal, which is used to drive the same ultra-low resistance electroacoustic unit, and obtain greater power based on the conversion, truly achieving low-cost, high-efficiency, and high-reliability speaker driving technology.
[0041] After the audio signal is amplified and processed, it is loaded on the high-frequency PWM carrier signal. The PWM signal can control the voltage and current in the circuit by changing the width of the pulse, thereby achieving efficient energy conversion. After the audio signal is loaded on the PWM carrier signal, the efficient energy conversion characteristics of the PWM signal can be used to improve the amplification efficiency of the audio signal and reduce energy loss. It also has low static power consumption and strong driving ability. It can easily drive low-resistance and high-power loads under very low power supply voltage conditions. The PWM signal is a digital signal, and its anti-interference ability is stronger than that of analog signals. Therefore, loading the audio signal on the PWM carrier signal can improve the anti-interference ability of the audio signal to a certain extent and reduce the impact of external noise on the audio signal.
[0042] By controlling the positive and negative half-waves of PWM separately, the waveform of the audio signal can be adjusted more accurately and distortion can be reduced. This fine control helps to maintain the original characteristics of the audio signal and improve fidelity. In power amplification applications, independent control of the positive and negative half-waves of PWM allows more efficient use of power, thereby improving power amplification efficiency. Because the PWM signal is a digital signal, it can more accurately control the waveform of current and voltage, thereby more efficiently converting electrical energy into audio energy. In the power amplification process, heat is an issue that needs to be paid attention to. By controlling the positive and negative half-waves of PWM and driving ultra-low internal resistance power devices separately, unnecessary energy loss can be reduced, thereby reducing heat generation and extending the service life of the equipment.
[0043] The above implementation modes are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field shall fall within the protection scope determined by the claims of the present invention.
Claims
1. A half-bridge low-resistance signal amplifier circuit, characterized in that: It includes a signal processing module, which includes a signal amplifying circuit and a high-frequency PWM carrier signal circuit. The high-frequency PWM carrier signal circuit includes a PWM positive half-wave amplifying circuit, a PWM negative half-wave amplifying circuit and a carrier signal modulator. The first output end of the signal amplifying circuit is electrically connected to the carrier signal modulator, the first output end of the carrier signal modulator is electrically connected to the PWM positive half-wave amplifying circuit, and the second output end of the carrier signal modulator is electrically connected to the PWM negative half-wave amplifying circuit.
2. The half-bridge low-resistance signal amplifier circuit according to claim 1, characterized in that: The signal processing module also includes an ALC gain control circuit and a power management circuit, the output end of the ALC gain control circuit is electrically connected to the input end of the power management circuit, the first output end of the power management circuit is electrically connected to the high-frequency PWM carrier signal circuit, and the second output end of the power management circuit is electrically connected to the carrier signal modulator through a clock signal generator.
3. The half-bridge low-resistance signal amplifier circuit according to claim 2, characterized in that: The output end of the signal amplifying circuit is electrically connected to the input end of the ALC gain control circuit through a first resistor and a diode a.
4. The half-bridge low-resistance signal amplifier circuit according to claim 3, characterized in that: It also includes a gate drive circuit, and the output end of the PWM positive half-wave amplifier circuit and the output end of the PWM negative half-wave amplifier circuit are electrically connected to the gate drive circuit respectively, and each of the gate drive circuits includes a voltage stabilizing circuit and an anti-dead zone correction circuit; the input end of one of the voltage stabilizing circuits is electrically connected to the third output end of the power management circuit, and the first output end of the voltage stabilizing circuit is electrically connected to the input end of the anti-dead zone correction circuit.
5. The half-bridge low-resistance signal amplifier circuit according to claim 4, characterized in that: The gate drive circuit also includes a bootstrap circuit, a first input end of the bootstrap circuit is electrically connected to the PWM positive half-wave amplifier circuit or the PWM negative half-wave amplifier circuit, and a second input end of one of the bootstrap circuits is electrically connected to the second output end of the voltage stabilizing circuit through a diode b.
6. The half-bridge low-resistance signal amplifier circuit according to claim 5, characterized in that: The gate drive circuit also includes a MOS drive circuit, which includes a first MOS power tube and a second MOS power tube. The drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the output end of the bootstrap circuit through a first capacitor.
7. The half-bridge low-resistance signal amplifier circuit according to claim 6, characterized in that: The source of the first MOS power tube is grounded, and the drain of the second MOS power tube is electrically connected to a power supply.
8. The half-bridge low-resistance signal amplifier circuit according to claim 6, characterized in that: It also includes an LC filter module, and the drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the LC filter module.
9. The half-bridge low-resistance signal amplifier circuit according to claim 8, characterized in that: The LC filter module includes an inductor, a second capacitor, a third capacitor and a second resistor. The drain of the first MOS power tube and the source of the second MOS power tube are electrically connected to the load through the inductor. The drain of the first MOS power tube is grounded through the inductor and the second capacitor in sequence; the source of the second MOS power tube is grounded through the inductor, the second resistor and the third capacitor in sequence.
10. The half-bridge low-resistance signal amplifier circuit according to claim 6, characterized in that: The third output terminal of the voltage stabilizing circuit is electrically connected to the gate of the first MOS power tube through an operational amplifier.