智能充电器的毕业设计.doc

PAGE 摘 要 随着移动电话、笔记本电脑、个人数字助理(PDA)、摄录像机及小体积高功率电器的广泛使用，锂离子电池被广泛地作供电电源。锂电池具有工作电压高、能量密度大、重量轻、寿命长及环保性佳等优点。目前锂离子电池已大量应用于可携带式电子产品上，未来更可作为电动工具交通工具等的动力来源，其未来需求及发展前景是相当广阔。 锂离子电池在各个领域的广泛应用，推动了对锂离子电池充电器及充电管理芯片的研究。充电管理芯片通常都具有以下特点：限流保护、电流短路与反充保护线路设计、自动及快速充电、充满电后自动关断等。有些还具有LED充电状态显示、低噪声、模拟微电脑控制系统等特点。锂离子的特点使得其对充电管理芯片的要求比较苛刻，充电方式通常采用恒流恒压方式。 本文所设计系统以EM78P458单片机为控制核心，电路按照实际电路功能可划分为系统指示灯电路、电源电压与环境温度采用电路、精确基准电压产生电路和开关控制电路。具体分析了锂离子电池的充电原理与充电方法、硬件电路设计、软件程序设计等。实现了电池充电、LED指示、保护机制及异常处理等功能。 关键词：锂离子电池 EM78P458 充电器 硬件电路 软件设计 Abstract With mobile phones, notebook computers, personal digital assistant (PDA), video recorders and small perturbation high volume of the widespread use of electrical power, lithium-ion batteries are widely for power supply. Lithium battery voltage with high energy density, light weight, long life and environmental advantages of good. The current lithium-ion battery has a large number can be used in portable electronic products, the future will be as electric tools, such as transport of power sources, its future needs and development prospects are very broad. Lithium-ion batteries in a wide range of applications in various fields, promote the lithium-ion rechargeable battery charger and management chip research. Charging management chips generally have the following characteristics: current limit protection, and counter-charge current short-circuit protection circuit design, automatic and quick and full of power after the automatic shutdown, and so on. Some also have LED charging status, low noise, analog microcomputer control system and so on. The characteristics of lithium-ion rechargeable management makes its chips on the request of relatively harsh, usually charging a constant current constant pressure methods. This paper designed to EM78P458 SCM system for the control of the core, the circuit functions in accordance with the actual circuit can be divided into light circuit system, power supply voltage and temperature using circuit, precision reference volt