摘  要

隨著移動電話、筆記本電腦、個人數(shù)字助理(PDA)、攝錄像機及小體積高功率電器的廣泛使用，鋰離子電池被廣泛地作供電電源。鋰電池具有工作電壓高、能量密度大、重量輕、壽命長及環(huán)保性佳等優(yōu)點。目前鋰離子電池已大量應用于可攜帶式電子產(chǎn)品上，未來更可作為電動工具交通工具等的動力來源，其未來需求及發(fā)展前景是相當廣闊。
鋰離子電池在各個領域的廣泛應用，推動了對鋰離子電池充電器及充電管理芯片的研究。充電管理芯片通常都具有以下特點：限流保護、電流短路與反充保護線路設計、自動及快速充電、充滿電后自動關斷等。有些還具有LED充電狀態(tài)顯示、低噪聲、模擬微電腦控制系統(tǒng)等特點。鋰離子的特點使得其對充電管理芯片的要求比較苛刻，充電方式通常采用恒流恒壓方式。
本文所設計系統(tǒng)以EM78P458單片機為控制核心，電路按照實際電路功能可劃分為系統(tǒng)指示燈電路、電源電壓與環(huán)境溫度采用電路、精確基準電壓產(chǎn)生電路和開關控制電路。具體分析了鋰離子電池的充電原理與充電方法、硬件電路設計、軟件程序設計等。實現(xiàn)了電池充電、LED指示、保護機制及異常處理等功能。

關鍵詞：鋰離子電池  EM78P458  充電器  硬件電路  軟件設計

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 voltage circuit and a switch control circuits. Specific analysis of the lithium-ion rechargeable battery with the principle of charging method, hardware design, software design. To achieve a battery charger, LED instructions, the protection mechanism and exception handling, and other functions.

Key words: lithium-ion battery charger  EM78P458  hardware circuit
Software design
 
目    錄
摘  要 1
Abstract 2
1  緒論 4
1.1  課題研究背景 4
1.2  充電器功能描述 6
1.3  本文內(nèi)容結構 7
2  系統(tǒng)設計框架與技術參數(shù) 8
2.1  系統(tǒng)設計框架 8
2.2  鋰離子電池充電原理 10
2.3  鋰電池充電方法 12
2.4  系統(tǒng)技術參數(shù) 15
2.5  系統(tǒng)技術方案 16
2.5.1  單片機 16
2.5.2  單片機外部擴展 17
3  充電器硬件設計 19
3.1  系統(tǒng)指示燈電路 19
3.2  電源電壓于環(huán)境溫度采樣電路 19
3.3  精確基準電源產(chǎn)成電路 20
3.4  開關控制電路 21
4  充電器軟件設計 22
4.1  系統(tǒng)軟件總體設計思路 22
4.2  系統(tǒng)主流程 23
4.3  電流程設計 25
5  匯編 27
5.1  變量定義與初始化程序模塊 27
5.1.1  系統(tǒng)變量定義 27
5.1.2  初始化程序模塊 30
5.2  主程序模塊 32
5.2.1  主程序模塊 32
5.2.2  AD_PT模塊 32
5.3  充電階段子程序模塊 35
5.3.1  預充電階段 35
5.3.2  快速充電階段 45
5.3.3  涓流充電階段 51
參考文獻 58
附圖 59