500W D类音频放大器的设计

发布时间：2018-07-15 09:21

【摘要】：D类音频放大器的概念在1958年就已经提出了,而直到功率半导体的崛起,才使得其迅速占领音频设备市场。D类音频放大器设计技术的不断改善,其性能指标逐步上升,以效率高、体积小、节能和数字化等优点不断取代传统音频技术,满足了更多人的需求。本文从辅助电源、驱动电路、输出级电路、保护电路及滤波电路等方面,详细设计了一款500W D类音频放大器。工作内容主要包括以下几个方面:1.首先比较了几种传统音频技术和D类功放之间的优缺点,并且详细描述了D类音频放大器的工作原理。阐述了几种D类放大器的调制方式及输出级电路,在此基础上提出本文的系统结构,其中着重解释Δ-Σ调制技术在D类音频放大器中的重要作用。2.设计D类音频放大器的核心电路及电源辅助电路。其中核心电路包括积分器、驱动电路、输出级电路、滤波电路和保护电路等。一方面,选择合适的控制芯片和功率元件,特别是功率元件采用实验室设计的MOSFET;另一方面需要对电路的参数进行详细设计以使得电路性能达到最优。辅助电路采用开关电源,为功放提供必要的供电。3.设计PCB版图,搭建出实际的电路并且进行调试。借助实验室的相关设备,对设计出来的电路在实际应用的环境下进行测试。包括辅助电源模块,D类音频放大模块以及整体的性能,调试相关参数使得测试结果达到最优。测试结果表明,所设计的D类音频放大器,在带载8Ω的情况下,功率为556W,空载情况下为16W。在选用输入峰峰值为2V,频率为1.7KHz的正弦信号时,测试输出为峰峰值为84.8V,频率为1.7KHz的正弦信号,信号被放大了约42.4倍,且几乎无失真发生,基本满足设计要求。此外,对电路调试中出现的功率器件失效问题进行了分析与讨论,并且给出了相应的解决措施。
[Abstract]:The concept of class D audio amplifier was put forward in 1958, but it was not until the rise of power semiconductor that it rapidly occupied the market of audio equipment. The design technology of class D audio amplifier improved continuously, and its performance index gradually increased. With the advantages of high efficiency, small size, energy saving and digitization, traditional audio technology has been replaced to meet the needs of more people. In this paper, a 500W D audio amplifier is designed in detail from the aspects of auxiliary power supply, drive circuit, output stage circuit, protection circuit and filter circuit. The work includes the following aspects: 1. Firstly, the advantages and disadvantages between several traditional audio technologies and D type power amplifier are compared, and the working principle of D class audio amplifier is described in detail. In this paper, several modulation modes and output stage circuits of class D amplifiers are described. Based on these, the system structure of this paper is presented, and the important role of 螖危 modulation technology in class D audio amplifiers is explained emphatically. The core circuit and power supply auxiliary circuit of class D audio amplifier are designed. The core circuits include integrator, drive circuit, output circuit, filter circuit and protection circuit. On the one hand, appropriate control chips and power elements are selected, especially the power elements are designed by MOSFETs designed in laboratory; on the other hand, detailed design of circuit parameters is needed to optimize the circuit performance. Auxiliary circuit uses switching power supply to provide the necessary power supply. 3. PCB layout design, build the actual circuit and debugging. With the help of laboratory equipment, the designed circuit is tested in practical application environment. It includes the auxiliary power module and the audio amplifier module of D class, and the whole performance. The test results are optimized by debugging the relevant parameters. The test results show that the power of the class D audio amplifier is 556 W in the case of 8 惟 load and 16 W in the case of no load. When the input peak value is 2 V and the frequency is 1.7 kHz, the test output is a sine signal with a peak of 84.8 V and a frequency of 1.7 kHz. The signal is amplified by about 42.4 times and has almost no distortion, which basically meets the design requirements. In addition, the failure problem of power devices in circuit debugging is analyzed and discussed, and the corresponding solutions are given.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN912.2

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