桂林电子科技大学
（开关电源电路设计与制作）
实训论文说明书
题 目：uc3842开关电源
院 （系）：信息与通信学院
专 业：电子信息工程
班 级：
学 号：
姓 名：
指导教师：
填表日期： 2012 年 12 月 18 日
桂林电子科技大学
摘 要
本文介绍一种以UC3842作为控制核心，根据UC3842的应用特点，设计了一种基于该电流型PWM控制芯片、实现输出电压可调的开关稳压电源电路。开关电源是利用现代电子技术，控制开关晶体管开通和关断的时间比率，维持稳定输出电压的一种电源，开关电源一般由脉冲宽度调制（PWM）和MOSFET构成。开关电源和线性电源相比，二者的成本都随着输出功率的增加而增长，但二者增长速率各异。开关电源比普通的线性电源效率高，开关电源的发展与应用在节约能源、节约资源及保护环境方面都具有重要的意义。
关键词：UC3842；开关电源；PWM
1
桂林电子科技大学
Abstract
This paper presents a UC3842, UC3842 application characteristics, based on the current-mode PWM control chip, adjustable output voltage switching power supply circuit design as the control core. The switching power supply is the use of modern electronic technology, controlling the time ratio of the switching transistor turn on and off to maintain a stable output voltage of a power supply, the switching power supply are generally and MOSFET constituted by a pulse width modulation (PWM). The switching power supply and compared to the linear power supply, the costs of both as the output power increases to grow, but the growth rate of the two different. The switching power supply is higher than ordinary linear power efficiency, the development and application of the switching power supply to save energy, conserve resources and protect the environment are of great significance.
Keywords: UC3842; switching power supplies; PWM
2