高精度误差放大器的研究 毕业论文.doc

摘 要 开关电源因其具有稳压输入范围宽、效率高、功耗低、体积小、重量轻等显著特点而得到了越来越广泛的应用，从家用电器设备到通信设施、数据处理设备、交通设施、仪器仪表以及工业设备等都有较多应用，尤其是作为便携式产品的电池提供高性能电源输出，比其他结构具有不可超越的优势。 开关电源的稳定性直接影响着电子产品的工作性能,误差放大器是直流开关电源系统中电压控制环路的核心部分，其性能优劣直接影响着整个直流开关电源系统的稳定性，因而对高性能误差放大器的分析是本论文的主要研究目标。本文误差放大器的分析基于Buck型DC-DC转换器，从系统稳定性、负载调整率及响应速度要求的角度出发，首先对该款Buck型DC-DC转换器的系统电压控制环路进行小信号分析,并对控制环路进行了零极点分布分析，确定环路补偿策略。最后基于系统级来分析误差放大器。关键词：开关电源；Buck型DC-DC转换器；误差放大器。 Abstract Due to their merits of wide input range, high efficiency, small in size and light in weight ect, switching power supplies are gaining more and more application areas in today’s modern world, ranging from domestic equipments to sophisticated communication and data handling systems, especially in portable devices, they have unsurpassable advantages. The rapid development of products in corresponding application areas requires the power supplies to have better performances. The robustness of switch—mode power supplies directly affect the performance of electronic devices. As one of the most important parts of switched mode DC to DC converters, error amplifier has significant influences on the voltage control loop’s stability. Thus this paper focuses on the design of high performance error amplifier for DC-DC converters based on system requirements analysis. A buck DC-DC converter was concerned, an error amplifier for the buck converter was designed from the points of view of system stability, load regulation and response speed requirements. At the first place, the Buck DC-DC converter’s voltage control loop stability and pole-zero analysis was done based on a small signal model of the voltage control loop, the compensation scheme was proposed. At last, according to the system level to analysis the error amplifier. Key words：Switching power; Buck DC-DC ConverterError Amplifier. 目 录 摘 要 I Abstract II 1. 诸 论 1 1.1 引言 1 1.2 本文研究的目的与意义 1 1.3 本论文主要研究内容 1 2. 开关电源基础及其类型 2 2.1 开关电源基础理论 2 2.1.1开关电源基本工作原理 2 2.1.2开关电源的组成 2 2.1.3开关电源的各种分类 3 2.2 开关电源典型结构[6] 4 2.3 DC-DC变换器 7 2.