Low Cost 8W Off-line LED Driver using RT8487

1rem

rt-dark-800

headline-3

false

Application Note Name

false

basicInfoTitle

rt-dark-300

applicationNoteInfo

left

buttonDownload

text-with-icon

secondary

i18n(button-item.download.button-label)

i18n(button-item.download.button-link)

_self

false

btnAllApplicationNote

text-with-icon

secondary

i18n(button-item.all-application-note.button-label)

i18n(button-item.all-application-note.button-link)

_self

false

width

fixed-width

basicInfoSection

withLine

2rem

width

full-width

<div class="WordSection1"> <h1>採用RT8487之8W 低成本離線式LED驅動器</h1> <h2 id="__Bookmark__0">摘要</h2> RT8487 是一具有內部高端驅動元件，可用於降壓或升–降壓架構中的邊界模式定電流控制器，能提供恆定輸出電流至LED負載。它包含了可實現高功率因數和低輸入電流總諧波失真率(THD)的特殊電路，同時也大大減少了外部元件數量。RT8487所用的SOT23-6封裝使它得維持小應用焊盤，並使得RT8487成為離線式LED驅動器非常具有成本效益的解決方案。 本應用須知提供了如何用RT8487設計一個符合成本效益的8W降壓型LED驅動器的詳細資訊。 <h2 id="__Bookmark__1">1.簡介</h2> 低成本離線式LED驅動器要求具備有高效率，滿足IEC61000 C級規格的高功率因數和低輸入電流總諧波失真率(THDi)，精確LED電流，快速啟動，僅用低成本標準零組件而構成，和電路設計簡單等的條件。以下探討在浮動式降壓架構下，以RT8487設計而成的8W LED驅動器；它能符合上述所有的條件。 主要規格: <ul> <li>輸入範圍230V ± 15% (稍作改變，可將此設計變成全範圍輸入)</li> <li>針對一般取代型照明應用：LED 燈串 27V，I-LED = 300mA ± 5%，P-out = 8W</li> <li>輸入電流總諧波失真率 (THDi) < 20% ，滿足IEC61000 C級規格</li> <li>啟動時間 < 300毫秒</li> <li>完整保護: 輸出短路，LED開路，過電流及過溫度保護</li> <li>無變壓器設計及使用標準低成本零組件，主要目的是降低材料清單 (BOM)的成本</li> </ul> <h2 id="__Bookmark__2">2.應用電路</h2> 8W LED 驅動器完整應用電路如下圖所示。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image001_zh-tw.jpg"> <img id="圖片 1" alt="Technical Document Image Preview" height="320" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image001_zh-tw.jpg" width="609"></a> 圖一 RT8487是用於浮動式控制器降壓架構下，其完整應用電路示於圖一。該晶片可控制高端開關晶體Q1的開始導通的時間，藉著串聯於降壓電感器之電阻RS來檢測LED的平均電流，如此可檢測到的是真正的負載電流。邊界導通模式(BCM) 切換也是透過檢測零電感電流（同樣是透過RS）而成。在最小汲極-源極電壓 (VDS) 時的高效率諧振開關點則是透過由R3調整的、從零電流偵測點(ZCD)算起的導通延遲時間來實現的，並透過智慧演算法控制導通時間以獲得高輸入功率因數和低輸入電流總諧波失真率(THDi)。 IC所需的偏壓是由D2和C2構成的自舉電路所提供，省去外加輔助線圈，所以只需用到一般標準的磁鼓線圈，而不需較貴、客製的變壓器。因啟動IC的偏壓電流低，所以可用高阻值的啟動電阻R1和R2，且依然能達到快速啟動（一般為123毫秒）。完整的應用電路可建構於一個18 x 36平方毫米的單面PCB。 <h2 id="__Bookmark__3">3.主要元件值的計算</h2> 以下各節將解釋各應用參數的設定。 設定平均輸出電流 流過LED燈串的平均輸出電流可由連於RT8487之 GND和SENSE兩接腳之間的外部電阻RS決定。由於RS是串連於電感器，LED的平均電流可以透過此電阻精確地檢測到。輸出電流IOUT和RS的關係可見如下: <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image002_zh-tw.png"> <img id="圖片 3" alt="Technical Document Image Preview" height="30" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image002_zh-tw.png" width="82"></a> 本應用中，LED電流定為300mA，所以 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image003_zh-tw.png"> <img id="圖片 5" alt="Technical Document Image Preview" height="30" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image003_zh-tw.png" width="129"></a> 選用電阻1Ω//4.7Ω以得0.824Ω。 啟動電阻 啟動電阻(R1+R2)的選擇條件是在最低輸入電壓下，經此二電阻的電流須大於RT8487的啟動電流，否則RT8487的Vcc可能永遠無法達到啟動電壓。其常規啟動電流為25µA。 啟動電阻也不能使啟動電流超過操作電流，否則VCC電壓會比自舉電路設的VCC還高，因此IC可能會啟動過壓保護(OVP)。操作電流通常為1mA。 啟動電阻值和VCC電容C2會決定啟動時間，定義如下: <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image004_zh-tw.png"> <img id="圖片 9" alt="Technical Document Image Preview" height="36" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image004_zh-tw.png" width="109"></a> 其中VUVLO為17V，而Istart-up可近似為： <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image005_zh-tw.png"> <img id="圖片 10" alt="Technical Document Image Preview" height="41" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image005_zh-tw.png" width="105"></a> 大多數應用中，C2多選用17µF。 且R1和R2都選用1MΩ，代入後，得其常規啟動電流為： <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image006_zh-tw.png"> <img id="圖片 15" alt="Technical Document Image Preview" height="35" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image006_zh-tw.png" width="140"></a> 啟動時間則為: <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image007_zh-tw.png"> <img id="圖片 16" alt="Technical Document Image Preview" height="30" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image007_zh-tw.png" width="137"></a> <div class="tb-system"> <table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="width: 508.4pt; border-collapse: collapse" width="678"> <tr style="height: 222.15pt"> <td style="width: 284.25pt; padding: .75pt .75pt .75pt .75pt; height: 222.15pt" valign="top" width="379"> <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image008_zh-tw.jpg"> <img id="Picture 8" alt="Technical Document Image Preview" height="258" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image008_zh-tw.jpg" width="346"></a> 圖二 </td> <td style="width: 224.15pt; padding: .75pt .75pt .75pt .75pt; height: 222.15pt" valign="top" width="299"> 圖二顯示在230V交流輸入，IC啟動時的波形。 當交流電源輸入時，流經R1和R2的電流即開始對C2充電。 當IC的VCC電壓超過UVLO值時，功率開關晶體即開始作開關動作，並快速地對輸出充電。 共測得的啟動時間為150msec。 </td> </tr> </table> </div> 輸入電容器的選擇 對高功率因數的應用來說，輸入電容C1必須夠小，才能整流正弦波的輸入電壓。輸入濾波電容器的額定電壓VCIN須夠大，以承受最大輸入電壓。100nF/500V薄膜電容器會是一個恰當的選擇。為減低差模電磁干擾(EMI)，可由兩個47nF電容器和一個適當的電感器組成π型濾波器來達成。 降壓電感器的選擇 由於在邊界導通模式下切換，降壓電感值會影響轉換器的切換頻率。若要較小尺寸的線圈，就選擇小的電感值，但它通常受限於IC最小導通時間（通常是0.5µsec）和最小關閉時間（通常是0.5µsec）。 最大電感值則受限於IC最大導通時間（通常是15µsec）和最大關閉時間（通常是33µsec）。 要計算電感值，首先要計算在整流過的正弦波峰上(Vpeak)的最大尖峰電流值(Ipeak): <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image009_zh-tw.png"> <img id="圖片 18" alt="Technical Document Image Preview" height="42" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image009_zh-tw.png" width="114"></a> 其中Pin為轉換器的輸入功率，a是LED電壓與降壓輸入電壓之比： <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image010_zh-tw.png"> <img id="圖片 19" alt="Technical Document Image Preview" height="32" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image010_zh-tw.png" width="49"></a> 而F(K(a)) 是為PFC降壓且能有低THD的一個複變函數： <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image011_zh-tw.png"> <img id="圖片 20" alt="Technical Document Image Preview" height="30" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image011_zh-tw.png" width="509"></a> <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image012_zh-tw.jpg"> <img id="Picture 9" alt="Technical Document Image Preview" height="289" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image012_zh-tw.jpg" width="355"></a> 圖三 在8W應用中，Pin可以由 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image013_zh-tw.png"> <img id="圖片 21" alt="Technical Document Image Preview" height="30" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image013_zh-tw.png" width="139"></a> 算出。(以效率為86%作估計) 在整流過的正弦波峰上，因數a先被算出: <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image014_zh-tw.png"> <img id="圖片 22" alt="Technical Document Image Preview" height="34" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image014_zh-tw.png" width="108"></a> 從圖三或公式(1)可得,<a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image015_zh-tw.png"><img id="圖片 26" alt="Technical Document Image Preview" height="35" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image015_zh-tw.png" width="273"></a> 電感值的範圍也可由此算出: <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image016_zh-tw.png"> <img id="圖片 27" alt="Technical Document Image Preview" height="37" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image016_zh-tw.png" width="200"></a> 若電流額定值為1.2A時，選擇330µH作為L1值，好在尺寸、成本和效率中的作最佳折衷選擇。 在正弦波峰上，開關頻率可由此而得： <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image017_zh-tw.png"> <img id="圖片 28" alt="Technical Document Image Preview" height="31" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image017_zh-tw.png" width="123"></a> (Tdelay由連於AND接腳的電阻決定，見下小節。) 設定開關導通延遲時間 電感電流為零之後，電感和開關結點上的總電容會產生諧振，該電容主要為開關晶體的汲極—源極電容。為儘可能減少開關晶體的開關損耗，RT8487可靈活調整下一導通週期的延遲時間，以期能在最大諧振點時導通，該點即對應到最小汲極—源極電壓值。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image018_zh-tw.jpg"> <img id="Picture 13" alt="Technical Document Image Preview" height="299" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image018_zh-tw.jpg" width="430"></a> 圖四 要決定所需的延遲時間，要考慮兩個因數： a. 從零電流偵測(ZCD)點到實際零電流點的延遲時間(如圖四之t1)。因為ZCD點是定義在Vsense = 20mV時，ZCD延遲時間可由此式算出: <a class="fancybox" href="/~/media/Richtek/Design%20Support/Technical%20Documentation/AN019/EN/Version1/image019.png?file=preview.png"> <img alt="Technical Document Image Preview" height="32" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image019_zh-tw.png" width="103"></a> 在此應用中，其值為： <a class="fancybox" href="/~/media/Richtek/Design%20Support/Technical%20Documentation/AN019/EN/Version1/image020.png?file=preview.png"> <img alt="Technical Document Image Preview" height="31" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image020_zh-tw.png" width="184"></a> b. 從零電流點(ZCD)到開關諧振最大值的延遲時間(如圖四之t2)也可由此式算出:<a class="fancybox" href="/~/media/Richtek/Design%20Support/Technical%20Documentation/AN019/EN/Version1/image021.png?file=preview.png"> <img alt="Technical Document Image Preview" height="22" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image021_zh-tw.png" width="114"></a> 其中CSW是開關結點的電容，主要就是開關晶體的汲極—源極電容；在本應用中，此電容值為38pF。諧振延遲時間即為<a class="fancybox" href="/~/media/Richtek/Design%20Support/Technical%20Documentation/AN019/EN/Version1/image022.png?file=preview.png"> <img alt="Technical Document Image Preview" height="23" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image022_zh-tw.png" width="215"></a> 最佳諧振導通點所需的總延遲時間Tdelay即為290nsec + 352nsec = 642nsec。 從零電流偵測點(ZCD)至下一開關晶體導通週期的延遲時間(Tdelay)可藉電阻R3調整，R3連接於晶片的AND接腳和GND接腳之間。 <a class="fancybox" href="/~/media/Richtek/Design%20Support/Technical%20Documentation/AN019/EN/Version1/image023.png?file=preview.png"> <img alt="Technical Document Image Preview" height="20" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image023_zh-tw.png" width="297"></a> <ul> <li>Tdelay =大約的延遲時間，以µsec為單位（從零電流偵測點開始：即Vsense= 20mV時）</li> <li>R3 阻值以kΩ為單位</li> </ul> 根據公式(2)，R3 = 8.2kΩ時可得628nsec的延遲時間。但最後將R3值設為 6.8KΩ，以補償由於開關晶體的導通時間所造成的額外延遲。下面的圖五顯示出在最佳諧振導通點時的開關波形。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image024_zh-tw.jpg"> <img id="Picture 6" alt="Technical Document Image Preview" height="294" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image024_zh-tw.jpg" width="394"></a> 圖五 開關晶體MOSFET的選擇 開關晶體電壓額定值須夠大，才能承受最大輸入峰值電壓及瞬間突起電源的裕量。最好選用汲極¬–源極額定值至少500V的開關晶體。開關晶體的額定電流值和溫度有關，為達到低功耗和高效率，選用2A的開關晶體。 順向二極體的選擇 當開關晶體關閉時，電流路徑是流經連接於開關的輸出點和接地之間的二極體(D1)。順向偏壓時，二極體必須有低順向導通電壓降和快速的恢復時間。二極體的反向電壓額定值則須大於最大輸入峰值電壓並加上裕量，而電流額定值須大於電感的峰值電流。為求低功耗和較高效率，選用600V/2A的快速二極體。 輸出電容的選擇 為實現高功率因數和低輸入電流總諧波失真率(THDi)，電感電流會包含相當大量的低頻漣波。輸出電容會過濾開關的和低頻漣波的電流以傳輸低漣波電壓至LED燈串。有了輸出漣波電壓的大小與LED燈串的微分電阻即可決定流過LED的漣波電流。在此低成本的設計中，選用220µF的電容器，大約可過濾330mApp流過LED燈串的漣波電流。為了減少這種漣波，須要選用較大的輸出電容。 <h2 id="__Bookmark__4">4. 主要性能的量測</h2> 圖六顯示輸入和輸出電壓和電流的波形。 從交流輸入波形可看出有高PFC和低THD，且平均LED輸出電流則精確地定於299mA。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image025_zh-tw.jpg"> <img id="Picture 14" alt="Technical Document Image Preview" height="245" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image025_zh-tw.jpg" width="604"></a> 圖六 圖七為開關時的波形。為要實現低THDi，電感電流峰值最好是LED平均電流的四倍之高。從單一開關週期可看出在最小汲極–源極電壓時，在邊界導通模式(BCM)切換的情形。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image026_zh-tw.jpg"> <img id="Picture 17" alt="Technical Document Image Preview" height="255" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image026_zh-tw.jpg" width="602"></a> 圖七 下表列出主要的性能參數。在電源電壓範圍內，它具有優異的LED電流穩定性，典型的效率(efficiency)為86%，且有滿足IEC61000 C類規格的低THD。 <div> <table border="1" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="width: 450.0pt; border-collapse: collapse; border: none" width="600"> <tr> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> Vin ac </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> Pin ac </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> PF </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> THD </td> <td style="width: 71.25pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="95"> V-LED </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> I-LED </td> <td style="width: 71.25pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="95"> Pout </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> Efficiency </td> <td style="width: 45.0pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="60"> Ploss </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 195.5 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 9.59 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0.96 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 11.6 </td> <td style="width: 71.25pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="95"> 27.69 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0.299 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 8.279 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 86.3% </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1.31 </td> </tr> <tr style="height: 13.5pt"> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 231.8 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 9.64 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 0.94 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 13.3 </td> <td style="width: 71.25pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="95"> 27.74 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 0.299 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 8.294 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 86.0% </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 1.35 </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 264.2 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 9.68 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0.90 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 17.7 </td> <td style="width: 71.25pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="95"> 27.68 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0.300 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 8.304 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 85.8% </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1.38 </td> </tr> </table> </div> <h2 id="__Bookmark__5">5. 總材料清單</h2> 完成一個8W LED驅動器的總材料清單，如下所示： <div> <table border="1" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="width: 450.0pt; border-collapse: collapse; border: none" width="600"> <tr> <td style="width: 46.25pt; border: solid #009EB8 1.0pt; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="62"> Item </td> <td style="width: 46.2pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="62"> Quantity </td> <td style="width: 68.85pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="92"> Reference </td> <td style="width: 106.8pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="142"> Part / Value </td> <td style="width: 73.95pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="99"> Footprint </td> <td style="width: 107.95pt; border: solid #009EB8 1.0pt; border-left: none; background: #009EB8; padding: .75pt .75pt .75pt .75pt" width="144"> Remark </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> F1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1A/250V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> --- </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> Fuse 1A </td> </tr> <tr style="height: 13.5pt"> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 2 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="92"> LX1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="142"> 4.7mH (DR0612) </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> DR0612 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> EMI drum coil </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 3 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> L1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 330µH (CKPK1012) </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> DR1012 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> Buck drum coil </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 4 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> CX1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 0.1µF/275Vac </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> DIP </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> X-capacitor </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 5 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> C1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 0.1µF/450V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> DIP </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> MPP Cap </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 6 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> C2 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1µF/50V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1206 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 7 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> C3 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 0.1µF/50V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0603 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 8 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> C4 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1nF/50V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0603 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 9 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> EC1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 220µF/35V </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> DIP </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> Output E-cap </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 10 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> RX1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 10K </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1206 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 11 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 2 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> R1, R2 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1M </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1206 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr style="height: 13.5pt"> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 12 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="92"> R3 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="142"> 68K </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 0603 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 13 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> R4 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 10R </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0805 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 14 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> R5 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 100R </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0603 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 15 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> R6 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 47k </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 0805 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 16 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> RS </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1R // 4R7 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1206 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 17 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> D1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> SF28 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> DIP </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> Fast 2A/600V </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 18 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> D2 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> FFM107 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> SOD-123L </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> Fast 1A/1000V </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 19 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> Extra-D </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> 1N4148 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> SOD-123 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 250mA/75V </td> </tr> <tr style="height: 13.5pt"> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 20 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="92"> DB </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt" width="142"> TB6S </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> --- </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt; height: 13.5pt"> 600V/1A diode bridge </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 21 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> Q1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> STD2HNK60 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> TO-251 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 2A/600V MOSFET </td> </tr> <tr> <td style="border: solid #009EB8 1.0pt; border-top: none; padding: .75pt .75pt .75pt .75pt"> 22 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> 1 </td> <td style="width: 68.85pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="92"> IC1 </td> <td style="width: 106.8pt; border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt" width="142"> RT8487GJ6 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> TSOT23-6 </td> <td style="border-top: none; border-left: none; border-bottom: solid #009EB8 1.0pt; border-right: solid #009EB8 1.0pt; padding: .75pt .75pt .75pt .75pt"> LED driver controller </td> </tr> </table> </div> <a name="c6"> </a> <h2 id="__Bookmark__6">6. 印刷電路板 (PCB) 的佈局</h2> 將8W LED驅動器的應用電路建構於一個小的單面PCB上。因為是浮動式控制器的拓撲結構，IC周圍的零組件都要緊密排放且靠近IC。佈局時，應為高電壓振幅提供足夠的沿面距離和隔空間隙的裕量。 要注意的是，這裡只是初步的佈局。若要達到更優化的性能表現，還需要進一步微調：降壓電感器相對於EMI線圈的方向需要作些修正，因目前L1的雜散磁場會耦合到LX1，反而量測到較高的EMI讀數。 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image027_zh-tw.jpg"> <img id="Picture 5" alt="Technical Document Image Preview" height="164" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image027_zh-tw.jpg" width="603"></a> 圖八 <a class="fancybox" href="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image028_zh-tw.jpg"> <img id="Picture 7" alt="Technical Document Image Preview" height="175" src="/content/dam/richtek-eds/resources/application-notes/an019/html-images-zh-tw/image028_zh-tw.jpg" width="603"></a> 圖九 <a name="c7"> </a> <h2 id="__Bookmark__7">7.結論</h2> 使用RT8487能夠設計出極具成本效益，同時具備良好性能，且滿足現今市場對LED驅動器要求的8W LED驅動器。 請瀏覽立錡的網站 <a class="link" href="http://www.richtek.com/LED/?utm_source=AN012&utm_medium=RTWWW&utm_campaign=AppNote" target="_blank"> http://www.richtek.com/LED/</a>，以了解更多立錡科技創新的LED驅動器解決方案的相關訊息。 <div class="WordSection2"> <table border="1" cellspacing="0" cellpadding="0" style="width: 637.5pt; border-collapse: collapse; border: medium none;" class="3-51"> <tbody> <tr style="height: 17pt;"> <td style="border-width: 1pt 1px 1px 1pt; border-style: solid; border-color: #009eb8; background-color: #009eb8; background-image: url(e); background-repeat: repeat; background-attachment: scroll; background-clip: border-box; background-origin: padding-box; background-size: auto auto; padding-right: 5pt; padding-left: 5pt; height: 17pt;" colspan="2"> 相關資源 </td> </tr> <tr> <td style="border-width: 1pt 1px 1px 1pt; border-style: solid; border-color: #009eb8; background-color: #ffffff; background-image: url(e); background-repeat: repeat; background-attachment: scroll; background-clip: border-box; background-origin: padding-box; background-size: auto auto; padding-right: 5pt; padding-left: 5pt; height: 17pt;"> 立錡科技電子報 </td> <td style="border-width: 1pt 1px 1px 1pt; border-style: solid; border-color: #009eb8; background-color: #ffffff; background-image: url(e); background-repeat: repeat; background-attachment: scroll; background-clip: border-box; background-origin: padding-box; background-size: auto auto; padding-right: 5pt; padding-left: 5pt; height: 17pt;"> <a class="link" href="http://www.richtek.com/My%20Richtek/Newsletters" target="_blank">訂閱立錡科技電子報</a> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: 1pt 1px 1px 1pt; border-style: solid; border-color: #009eb8; background-color: #ffffff; background-image: url(e); background-repeat: repeat; background-attachment: scroll; background-clip: border-box; background-origin: padding-box; background-size: auto auto; padding-right: 5pt; padding-left: 5pt; height: 17pt;"> 檔案下載 </td> <td style="border-width: 1pt 1px 1px 1pt; border-style: solid; border-color: #009eb8; background-color: #ffffff; background-image: url(e); background-repeat: repeat; background-attachment: scroll; background-clip: border-box; background-origin: padding-box; background-size: auto auto; padding-right: 5pt; padding-left: 5pt; height: 17pt;"> <a class="link" href="http://www.richtek.com/Design%20Support/Technical%20Document/~/media/AN%20PDF/AN019_TW.ashx">PDF 下載</a> </td> </tr> </tbody> </table> </div> </div>

false

i18n(article-attachment.related-product-list.title)

_ATTACHMENT_HIDDEN_FIELD_

related-products

_ATTACHMENT_HIDDEN_FIELD_

applicationNoteArticle

width

fixed-width

articleSection

application-note

true

relatedProductList

left

btnAllApplicationNote2

text-with-icon

secondary

i18n(button-item.all-application-note.button-label)

i18n(button-item.all-application-note.button-link)

_self

false

width

fixed-width

productListSection

100