它激式开关电源毕业设计剖析.doc

小功率开关电源设计 摘 要 电源是实现电能变换和功率传递的主要设备。在信息时代，农业、能源、交通运输、通信等领域迅猛发展，对电影产业提出个更多、更高的要求，如节能、节材、减重、环保、安全、可靠等。这就迫使电源工作者不断的探索寻求各种乡关技术，做出最好的电源产品，以满足各行各业的要求。开关电源是一种新型的电源设备，较之于传统的线性电源，其技术含量高、耗能低、使用方便，并取得了较好的经济效益。 CR6853芯片具有优化的图腾驱动电路以及电流模式PWM控制器，是一种性能优良的电流控制型脉宽调制器。假如由于某种原因使输出电压升高时，脉宽调制器就会改变驱动信号的脉冲宽度，亦即占空比D，使斩波后的平均值电压下降，从而达到稳压目的，反之亦然。CR6853可以直接驱动MOS管、IGBT等，适合于制作小功率开关电源。由于器件设计巧妙，由主电源电压直接启动，构成电路所需元件少，非常符合电路设计中“简洁至上”的原则。 关键词：开关电源，CR6853，脉宽调制，功率， EX-STIMULUS POWER-SWITCH DESIGN ABSTRACT Power is to achieve power conversion and power transmission major equipment. In the information age, agriculture, energy, transportation, communications and other areas Power of the film industry make a greater and higher requirements，such as energy, materials, weight reduction, environmental protection, safety and reliability. This has forced the power workers have been exploring the technology for a variety of rural customs, the power to make the best products to meet the requirements of all walks of life. Switching power supply is a new type of power supply, compared to traditional linear power supply, high technology, low energy consumption, easy to use, and has achieved good economic results. CR6853 is an excellent current-controlled pulse width modulator. If for some reason, the output voltage increases, the pulse width modulator drive signal will change the pulse width, that is, the duty cycle D, so that the average voltage drop after the chopper to achieve the regulator end, and vice versa how ever. CR6853 can control direct drive MOS, IGBT, etc., suitable for the production of 20 ~ 80W low-power switching power supply. As the device is cleverly designed, launched by the main power supply voltage directly to form circuit components required for a small, very consistent with circuit design, simplicity first principle. KEY WORDS: Switching Power Supply，CR6853，PWM，power，IGBT 目　录 前　言 1 第章 开关电源介绍 2 1.1 开关电源概述 2 1.1.1 开关电源工作原理 2 1.1.2 开关电源的设计 3 1.1.3 开关电源的特点 4 1.2 开关器件 4 1.2.1开关器