【正文】 摘 要 本設(shè)計(jì)由 STC89S52單片機(jī)系統(tǒng)， PWM 脈寬調(diào)制信號(hào)控制芯片 TL494，開關(guān)電源 Buck 串聯(lián)降壓電路 , A/D模塊 , D/A模塊 , 鍵盤輸入和 LCD顯示輸出模塊，制作了一個(gè)輸出電壓為 5V15V可調(diào) DC/DC模塊構(gòu)成的供電系統(tǒng)。電源模塊由 TL494控制 Buck電流構(gòu)成，通過(guò)電壓反饋控制將輸出電壓穩(wěn)壓到所需要的電壓。 關(guān)鍵詞 ： STC89C52單片機(jī) 。 PWM 脈寬調(diào)制信號(hào) 。 TL494。 Buck circuit 安徽工程大學(xué)畢業(yè)設(shè)計(jì) (論文 ) 3 目 錄 摘 要 .................................................................................................................................... I Abstract .............................................................................................................................. II 第一章 緒 論 .................................................................................................................... 1 引言 ......................................................................................................................... 1 開關(guān)電源簡(jiǎn)介 ........................................................................................................ 1 第二章 開關(guān)電源 DC/DC 電路設(shè)計(jì)思路 ........................................................................ 2 開關(guān)電源的工作原理 ............................................................................................ 2 開關(guān)電源的常見(jiàn)拓?fù)浣Y(jié)構(gòu)簡(jiǎn)介 ............................................................................ 3 開關(guān)電源 DC/DC 拓?fù)湓O(shè)計(jì)思路 .......................................................................... 4 DC/DC 基本拓?fù)湓O(shè)計(jì)方案 .......................................................................... 4 DC/DC 電路實(shí)現(xiàn) .................................................................................................... 5 DC/DC 回路參數(shù)設(shè)計(jì) ......................................................................................... 7 系統(tǒng)供電模塊設(shè)計(jì) ................................................................................................ 8 整流濾波電路設(shè)計(jì) ...................................................................................... 8 工作輔助電源參數(shù)設(shè)計(jì) .............................................................................. 9 第三章 控制系統(tǒng)的設(shè)計(jì)思路 .......................................................................................... 10 單片機(jī)模塊的設(shè)計(jì) ...............................................................................................11 STC89C52 性能簡(jiǎn)介 ...................................................................................11 最小系統(tǒng)設(shè)計(jì) ............................................................................................ 12 A/D 模塊設(shè)計(jì) ........................................................................................................ 12 芯片介紹 ..................................................................................................... 12 TLC549 工作時(shí)序 ....................................................................................... 13 A/D 電路設(shè)計(jì) .............................................................................................. 14 D/A 模塊設(shè)計(jì) ....................................................................................................... 15 D/A 芯片功能介紹 ..................................................................................... 15 D/A 芯片 I2C 總線數(shù)據(jù)通信基本協(xié)議 ..................................................... 15 接口電路的設(shè)計(jì) .................................................................................................. 17 顯示接口電路設(shè)計(jì) ..................................................................................... 17 顯示接口電路設(shè)計(jì) .................................................................................... 17 第四章 程序設(shè)計(jì) .............................................................................................................. 19 主程序流程圖的設(shè)計(jì) .......................................................................................... 19 鍵盤掃描程序設(shè)計(jì) .............................................................................................. 20 A/D 程序設(shè)計(jì) ........................................................................................................ 21 D/A 程序設(shè)計(jì) ....................................................................................................... 22 第五章 系統(tǒng) 仿真 ............................................................................................................ 23 倪才山：基于單片機(jī)的 BUCK 降壓電路 4 仿真 儀器 .............................................................................................................. 23 仿真 方法 .............................................................................................................. 23 仿真 結(jié)果與 分析 .................................................................................................. 23 參考文獻(xiàn) .......................................................................................................................... 24 附錄一：系統(tǒng)整體原理圖 ......................................................................................... 29 附錄 二 ：程序代碼 ...................................................................................................... 31 結(jié)論與展望 ........................................................................... 致 謝 ............................................................................................................................ 39