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单刀音频功率放大器的设计
摘要
本次课程设计题目为音频功率放大器，简称音频功放，音频功率放大器主要用于推动扬声器发声，凡发声的电子产品中都要用到音频功放。
设计中主要采用OP07进行音频放大器的设计，OP07芯片是一种低噪声，非斩波稳零的双极性运算放大器集成电路。由于OP07具有非常低的输入失调电压（对于OP07A最大为25μV），所以OP07在很多应用场合不需要额外的调零措施。设计中的音频功率放大器主要由直流稳压电源、前置放大电路、二级放大电路和功率放大电路组成。前置放大电路采用了反相比例运算放大器，二级放大电路用一个低通滤波器和一个高通滤波器组成一个带通滤波器，功率放大电路采用了OCL电路。直流电源采用桥式电路进行整流，输出则采用了三端集成稳压器。
对前置放大电路和二级放大电路进行了输入、输出分析和频率响应分析。对功率放大电路进行了输入和输出功率分析。对直流电源进行了输出电压验证。最后对总电路进行了输入、输出分析、频率响应分析、噪声分析。
关键词： OP07 音频功率放大器
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Abstract
The curriculum design entitled the audio power amplifier, referred to as audio amplifier, audio power amplifier is mainly used to promote the speaker sound, and where the sound of electronic products to be used in audio amplifier.
The main design using the OP07 audio amplifier design, the OP07 chip is a low-noise, non-chopper-stabilized bipolar op amp IC. OP07 has very low input offset voltage (for OP07A 25μV), OP07 in many applications do not require additional zero measures. The design of audio power amplifier by the DC power supply, preamplifier circuit, two amplification circuit and power amplifier circuit. Preamplifier circuit using a reversed-phase proportion of op amp, two amplifier with a low-pass filter and a high-pass filter composed of a band pass filter, power amplifier OCL circuit. The DC power bridge circuit rectifier, the output uses a three-terminal integrated voltage regulator.
Preamplifier and two amplifier input, output and frequency response analysis. Power amplifier input and output power analysis. Validation of the output voltage of DC power. Finally, the total circuit input-output analysis, frequency response analysis, noise analysis.
Key words: OP07 audio power amplifier
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目 录
摘要 ........................................................................................................................................... I Abstract .................................................................................................................................... II 第一章 音频放大器的概述 ..................................................................................................... 1
1.1音频放大电路的回顾 ................................................................................................. 1 1.2音频功率放大器的介绍 ............................................................................................. 1
1.2.1 A类(甲类)功率放大器 ................................................................................ 2 1.2.2 B类(乙类)功率放大器................................................................................. 2 1.2.3 AB类(甲乙类)功率放大器 .......................................................................... 2 1.2.4 C类(丙类)功率放大器................................................................................. 2 1.2.5 D类(丁类)功率放大器 ................................................................................ 3 1.3放大器的技术指标 ..................................................................................................... 3 第二章 音频功率放大器的设计 ............................................................................................. 6
2.1 设计方案分析 ........................................................................................................... 6 2.2前置放大电路设计 ..................................................................................................... 6 2.3二级放大电路设计 ..................................................................................................... 8
2.2.1 低通滤波器设计 ............................................................................................. 8 2.2.2 高通滤波器设计 ........................................................................................... 10 2.2.3 二级放大电路电路设计 ............................................................................... 12 2.4功率放大器设计 ....................................................................................................... 12 2.5 直流稳压电源设计 .................................................................................................. 13 2.6 OP07的功能介绍 ..................................................................................................... 14 第三章 电路的仿真 ............................................................................................................... 16
3.1 前置电路的仿真 ...................................................................................................... 16
3.1.1 输入与输出分析 ........................................................................................... 16 3.1.2 电路频率响应特性分析 ............................................................................... 17 3.2二级放大电路仿真 ................................................................................................... 18
3.2.1电路输入与输出分析 .................................................................................... 18 3.2.2电路频率响应特性分析 ................................................................................ 19
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