【正文】 upply are analyzed. A singlechip switching power supply is designed according to the features of the chip which output power is 22W and output voltage are +5V,12V and +12V. Second, the external circuits of system include five parts, these are input rectifierfilter circuit, high frequency transformer, clampprotect circuit, output rectifierfilter circuit and feedback circuit. According to the design requirements, the detailed analysis of the five parts is presented, calculation of the values of the parameters and selection of the ponents are provided. At last, the power supplies have high efficiency, low ripple, stability output voltage and excellent electrical characteristics, and are used as control power supply of instruments and meters. Keywords： Switching power supply。 High frequency transformer 目 錄 1 緒論 ............................................................................................................................................ 1 開(kāi)關(guān)電源概述 ...................................................................................................................... 1 開(kāi)關(guān)電源國(guó)內(nèi)外發(fā)展?fàn)顩r與趨勢(shì) .................................................................................... 2 開(kāi)關(guān)電源的工作原理 ......................................................................................................... 3 開(kāi)關(guān)電源的分類(lèi) ................................................................................................................. 4 開(kāi)關(guān)電源變換器的基本電路 ............................................................................................ 6 開(kāi)關(guān)電源的應(yīng)用 ............................................................................................................... 10 開(kāi)關(guān)電源中的功率開(kāi)關(guān)器件 .......................................................................................... 10 課題簡(jiǎn) 介 ............................................................................................................................ 11 所選課題的意義 ............................................................................................................ 11 本課題的研究?jī)?nèi)容、研究方法 ................................................................................... 12 2 單片開(kāi)關(guān)電源的工作原理和分類(lèi) ........................................................................................ 13 單片開(kāi)關(guān)電源的基本原理 ............................................................................................... 13 單片開(kāi)關(guān)電源的兩種工作模式 ................................................................................... 14 單片開(kāi)關(guān)電源反饋電路的四種基本類(lèi)型 .................................................................. 15 單片開(kāi)關(guān)電源的產(chǎn)品分類(lèi) [9]............................................................................................ 16 三端單片開(kāi)關(guān)電源 ........................................................................................................ 16 TinySwitch 系列四端開(kāi)關(guān)電源 ................................................................................... 19 MC33370 系列五端單片開(kāi)關(guān)電源 .............................................................................. 20 TOPSwitch 單片開(kāi)關(guān)電源系列產(chǎn)品 .............................................................................. 22 TOPSwitch 系列 器件簡(jiǎn)介 ........................................................................................... 22 TOPSwitch 產(chǎn)品分類(lèi)、性能及結(jié)構(gòu)特點(diǎn) ................................................................... 23 TOPSwitch Ⅱ系列器件 ................................................................................................ 25 TOPSwitch II 系列單片開(kāi)關(guān)電源的性能特點(diǎn) [10] ..................................................... 25 TOPSwitch II 系列單片開(kāi)關(guān)電源的工作原理 ......................................................... 27 五端單片開(kāi)關(guān)電源的原理與應(yīng)用 .................................................................................. 29 TOPSwitchFX 系列芯片的性能特點(diǎn) ......................................................................... 30 TOPSwitchFX 的管腳功能和內(nèi)部結(jié)構(gòu) .................................................................... 30 3 單片開(kāi)關(guān)電源的系統(tǒng)設(shè)計(jì) .................................................................................................... 32 單片開(kāi)關(guān)電源功率計(jì)算 ................................................................................................... 33 TOP224Y 的主要性能特點(diǎn)和工作原理 ........................................................................ 33 性能特點(diǎn) [11] ................................................................................................................... 33 工作原理 [12] ................................................................................................................... 34 開(kāi)關(guān)電源電路的總體設(shè)計(jì) ............................................................................................... 35 輸入整流濾波電路的設(shè)計(jì) ........................................................................................... 36 高頻變壓器的設(shè)計(jì) ........................................................................................................ 37 箝位保護(hù)電路的設(shè)計(jì) .................................................................................................... 41 輸出整流濾波電路的設(shè)計(jì) [14] ....................................................................................... 41 反饋回路的設(shè)計(jì) [15] ........................................................................................................ 43 4 開(kāi)關(guān)電源的 PCB 設(shè)計(jì)技術(shù) .................................................................................................. 45 Protel99 SE 原理圖設(shè)計(jì) ................................................................................................... 45 印刷電路板（ PCB）設(shè)計(jì) .............................................................................................. 46 PCB 圖基本設(shè)計(jì)方法和原則 .......................................................................................... 47 PCB 布局、布線設(shè)計(jì) ................................................................................................... 47 印刷電路板圖設(shè)計(jì)的基本原則要求 ..............................................................