從(cong)為(wei)(wei)平板電(dian)(dian)腦或(huo)智能(neng)手機(ji)電(dian)(dian)池(chi)充電(dian)(dian)到(dao)為(wei)(wei)膝上型電(dian)(dian)腦或(huo)家用路由器(qi)供電(dian)(dian)，電(dian)(dian)源(yuan)(yuan)適(shi)(shi)配器(qi)長期(qi)以來(lai)(lai)都是人們日常生活的(de)(de)(de)(de)(de)必要(yao)(yao)組成(cheng)部(bu)分。對于(yu)(yu)將電(dian)(dian)源(yuan)(yuan)適(shi)(shi)配器(qi)與其(qi)產品搭配到(dao)一起的(de)(de)(de)(de)(de)消費(fei)電(dian)(dian)子原(yuan)設備制(zhi)造商(shang)（OEM）而言，需要(yao)(yao)因(yin)應兩(liang)項關鍵推動(dong)因(yin)素，即確保提供高能(neng)效(xiao)等級(ji)并滿足(zu)安(an)全規(gui)范，同時還(huan)需提供緊湊的(de)(de)(de)(de)(de)外形(xing)因(yin)數(shu)。近(jin)年(nian)來(lai)(lai)，由于(yu)(yu)結合了(le)政府法規(gui)及(ji)美國(guo)“能(neng)源(yuan)(yuan)之(zhi)星”、歐盟生態設計指令及(ji)中國(guo)標準(zhun)化研究(jiu)院（CNIS）等能(neng)效(xiao)項目，業界非(fei)常注重通過減小待(dai)機(ji)模式下的(de)(de)(de)(de)(de)使用的(de)(de)(de)(de)(de)電(dian)(dian)能(neng)來(lai)(lai)降低適(shi)(shi)配器(qi)的(de)(de)(de)(de)(de)總體能(neng)耗(hao)等級(ji)。本文將探(tan)討推動(dong)最新(xin)要(yao)(yao)求(qiu)的(de)(de)(de)(de)(de)新(xin)興技術(shu)趨勢，包括要(yao)(yao)求(qiu)減少使用的(de)(de)(de)(de)(de)外部(bu)元器(qi)件數(shu)量(liang)、使設計更時髦(mao)輕薄的(de)(de)(de)(de)(de)工藝。

　　待機(ji)能(neng)耗(hao)(hao)有時候(hou)也(ye)稱作“吸血鬼能(neng)耗(hao)(hao)”或是(shi)“虛負載(zai)”,指(zhi)的是(shi)電(dian)子設備及電(dian)器在關斷電(dian)源但仍然插在電(dian)源插座上時消(xiao)耗(hao)(hao)的電(dian)能(neng)。以美(mei)國(guo)為例，待機(ji)能(neng)耗(hao)(hao)約占美(mei)國(guo)家(jia)庭平均總(zong)能(neng)耗(hao)(hao)約10%.這(zhe)相當于令(ling)人驚愕(e)的129太瓦時（即為1,290億千瓦時）的電(dian)能(neng)，或者(zhe)是(shi)36座400兆瓦發電(dian)廠(chang)輸出(chu)的電(dian)能(neng)，導致每年排放7,500萬噸二氧化碳。

　　在(zai)(zai)美國(guo)(guo)，2008年7月1日生(sheng)效的(de)(de)現行聯(lian)邦標(biao)準(zhun)要(yao)(yao)求(qiu)功率(lv)(lv)低于(yu)(yu)(yu)250 W的(de)(de)電(dian)(dian)(dian)源(yuan)空載能(neng)(neng)(neng)耗低于(yu)(yu)(yu)500 mW.最近(jin)，美國(guo)(guo)能(neng)(neng)(neng)源(yuan)部（DOE）提(ti)出了更嚴格(ge)的(de)(de)電(dian)(dian)(dian)池充電(dian)(dian)(dian)器及(ji)電(dian)(dian)(dian)子(zi)產品(pin)電(dian)(dian)(dian)源(yuan)能(neng)(neng)(neng)效標(biao)準(zhun)，并(bing)將(jiang)于(yu)(yu)(yu)2013年7月1日生(sheng)效。根據新(xin)標(biao)準(zhun)，銘牌輸出功率(lv)(lv)介于(yu)(yu)(yu)49至250 W之間（典(dian)型筆記本視頻(pin)器功率(lv)(lv)位(wei)于(yu)(yu)(yu)此范圍）的(de)(de)交(jiao)流(liu)-直流(liu)（AC-DC）外部電(dian)(dian)(dian)源(yuan)的(de)(de)最大空載能(neng)(neng)(neng)耗必須低于(yu)(yu)(yu)0.210 W.然(ran)而，這些國(guo)(guo)家(jia)(jia)標(biao)準(zhun)通(tong)常落(luo)后于(yu)(yu)(yu)其它(ta)標(biao)準(zhun)及(ji)市場要(yao)(yao)求(qiu)。美國(guo)(guo)1975年能(neng)(neng)(neng)源(yuan)政策及(ji)節能(neng)(neng)(neng)法案(an)（EPCA）規定：任何新(xin)的(de)(de)節能(neng)(neng)(neng)標(biao)準(zhun)的(de)(de)制(zhi)定必須旨在(zai)(zai)提(ti)供最大程度的(de)(de)能(neng)(neng)(neng)效提(ti)升，不僅(jin)要(yao)(yao)在(zai)(zai)技術上可(ke)(ke)行，也要(yao)(yao)具備經濟合理性。因此，這些國(guo)(guo)家(jia)(jia)標(biao)準(zhun)通(tong)常并(bing)不代表“一流(liu)的(de)(de)”性能(neng)(neng)(neng)。諸多電(dian)(dian)(dian)源(yuan)制(zhi)造商(shang)要(yao)(yao)求(qiu)將(jiang)空載能(neng)(neng)(neng)耗限制(zhi)到(dao)盡可(ke)(ke)能(neng)(neng)(neng)地低，從(cong)而將(jiang)其產品(pin)與(yu)競(jing)爭產品(pin)區別開來。

　　圖1:美國(guo)能源(yuan)部提出(chu)的AC-DC外部電源(yuan)節能標準(zhun)

　　在(zai)(zai)能效(xiao)(xiao)(xiao)標準(zhun)(zhun)上最(zui)為進取(qu)的(de)(de)政府(fu)機(ji)構很(hen)可能是(shi)美國(guo)(guo)(guo)加(jia)(jia)(jia)州(zhou)(zhou)。電(dian)(dian)(dian)(dian)(dian)源制造商(shang)可不想(xiang)提供僅針對加(jia)(jia)(jia)州(zhou)(zhou)的(de)(de)特定型號(hao)產品，因此，加(jia)(jia)(jia)州(zhou)(zhou)標準(zhun)(zhun)的(de)(de)實(shi)際(ji)影響范(fan)圍要廣(guang)得多(duo)。例如，美國(guo)(guo)(guo)加(jia)(jia)(jia)州(zhou)(zhou)在(zai)(zai)2012年(nian)1月(yue)出(chu)臺的(de)(de)新的(de)(de)電(dian)(dian)(dian)(dian)(dian)器(qi)能效(xiao)(xiao)(xiao)規范(fan)將電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)系統作為重(zhong)要焦點。加(jia)(jia)(jia)州(zhou)(zhou)每年(nian)有超過1.7億(yi)個充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)被用于(yu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)，根據推測，在(zai)(zai)此特別(bie)領域提升能效(xiao)(xiao)(xiao)，每年(nian)將可節(jie)省(sheng)2,200吉瓦時(shi)（即22億(yi)千瓦時(shi)）的(de)(de)電(dian)(dian)(dian)(dian)(dian)能。這(zhe)些電(dian)(dian)(dian)(dian)(dian)路足夠為35萬(wan)個家庭供電(dian)(dian)(dian)(dian)(dian)，相(xiang)當(dang)于(yu)為住宅/商(shang)業(ye)(ye)用電(dian)(dian)(dian)(dian)(dian)賬單每年(nian)節(jie)省(sheng)3.06億(yi)美元。美國(guo)(guo)(guo)加(jia)(jia)(jia)州(zhou)(zhou)能源委(wei)員會（CEC）實(shi)施的(de)(de)這(zhe)些能效(xiao)(xiao)(xiao)規范(fan)要求手機(ji)、個人(ren)照護設備(bei)及電(dian)(dian)(dian)(dian)(dian)動工具所使用的(de)(de)所有消費類充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)在(zai)(zai)2013年(nian)2月(yue)前必須(xu)遵(zun)從，而(er)工業(ye)(ye)類充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)須(xu)在(zai)(zai)未來12個月(yue)內(nei)遵(zun)從。美國(guo)(guo)(guo)其(qi)他幾個州(zhou)(zhou)希望遵(zun)循加(jia)(jia)(jia)州(zhou)(zhou)降低待機(ji)能耗(hao)限(xian)制值的(de)(de)范(fan)例。

　　圖2:電(dian)動(dong)工具所用的(de)典型老(lao)式充(chong)電(dian)系統

　　圖2介紹了過(guo)去常用(yong)的基(ji)本充電(dian)器系統(tong)電(dian)路圖。此特(te)別案(an)例使用(yong)鎳鉻（NiCd）電(dian)池來為(wei)電(dian)動工(gong)具充電(dian)。電(dian)池在(zai)1小時內的電(dian)量標為(wei)C.例如，以0.5 C的充電(dian)速率來為(wei)額(e)定容量600 mAh的電(dian)池充電(dian)，使用(yong)300 mA充電(dian)電(dian)流(liu)要經(jing)歷超過(guo)2小時才能完全充滿電(dian)池。

　　圖2中的(de)電路(lu)能(neng)以0.1 C的(de)恒定充電速率。由(you)于充電器(qi)(qi)的(de)60 Hz變壓器(qi)(qi)的(de)設計意(yi)圖是維持低成本，而非提(ti)供高(gao)(gao)能(neng)效(xiao)等(deng)級，空載能(neng)耗(hao)(hao)通常將高(gao)(gao)于0.5 W,如此高(gao)(gao)的(de)空載能(neng)耗(hao)(hao)不(bu)再能(neng)夠令人接受。早期想法是使充電器(qi)(qi)能(neng)效(xiao)更高(gao)(gao)，但(dan)不(bu)注意(yi)事實上充電后電路(lu)會(hui)持續(xu)無限(xian)期地浪(lang)費電能(neng)。這已(yi)經(jing)被(bei)證(zheng)明是一種有點(dian)誤導(dao)的(de)視(shi)角。

　　即便是當今市場上的許多充(chong)(chong)電(dian)(dian)(dian)(dian)器，也仍然缺(que)乏檢測電(dian)(dian)(dian)(dian)池是否完(wan)(wan)全充(chong)(chong)滿的能(neng)力(li)，且因(yin)此在充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)完(wan)(wan)成后仍然持續提(ti)供電(dian)(dian)(dian)(dian)能(neng)給電(dian)(dian)(dian)(dian)池，因(yin)而浪費(fei)電(dian)(dian)(dian)(dian)能(neng)（釋放為熱量）。通過(guo)使用(yong)可以關閉完(wan)(wan)全充(chong)(chong)滿之電(dian)(dian)(dian)(dian)池的充(chong)(chong)電(dian)(dian)(dian)(dian)通道，電(dian)(dian)(dian)(dian)能(neng)就不(bu)會(hui)無謂地浪費(fei)，電(dian)(dian)(dian)(dian)池也不(bu)會(hui)置于損壞的風險(xian)。

    提供低(di)待機能耗工(gong)作的創新方案

　　家庭中一(yi)項常(chang)見(jian)的(de)待機能(neng)耗(hao)源頭就是(shi)筆(bi)記(ji)本適(shi)配(pei)器(qi)(qi)(qi)。這(zhe)些適(shi)配(pei)器(qi)(qi)(qi)相當多的(de)使用時(shi)間是(shi)在筆(bi)記(ji)本電(dian)(dian)腦斷開連接或關斷的(de)情況(kuang)下(xia)在桌子底下(xia)度過的(de)。如(ru)今典型的(de)市售筆(bi)記(ji)本適(shi)配(pei)器(qi)(qi)(qi)在空(kong)(kong)載(zai)條件下(xia)約(yue)消耗(hao)300 mW至(zhi)500 mW的(de)能(neng)耗(hao)。然而，許(xu)多領先制造商如(ru)今要求(qiu)下(xia)一(yi)代筆(bi)記(ji)本適(shi)配(pei)器(qi)(qi)(qi)的(de)空(kong)(kong)載(zai)能(neng)耗(hao)限制到低于30 mW,從而使其產品與競爭產品區(qu)域開來。圖(tu)3顯示(shi)了65 W筆(bi)記(ji)本適(shi)配(pei)器(qi)(qi)(qi)用下(xia)一(yi)代充電(dian)(dian)系(xi)統(tong)的(de)簡(jian)化示(shi)例。此(ci)電(dian)(dian)路最重(zhong)要的(de)元器(qi)(qi)(qi)件就是(shi)固定頻率(lv)電(dian)(dian)流(liu)模式控制器(qi)(qi)(qi)IC及次級端開關電(dian)(dian)源（SMPS）控制器(qi)(qi)(qi)IC.

　　圖(tu)(tu)3:帶(dai)空載檢測功能(neng)的先進充電(dian)電(dian)路簡化電(dian)路圖(tu)(tu)

　　這(zhe)示例中(zhong)指定的(de)(de)(de)(de)(de)固(gu)定頻率電(dian)(dian)(dian)(dian)(dian)流(liu)模式控制器（即安(an)森美半導體的(de)(de)(de)(de)(de)NCP1246）經(jing)過了(le)專門優(you)化(hua)，在(zai)(zai)空(kong)載(zai)及輕載(zai)條件(jian)下消耗(hao)(hao)極低的(de)(de)(de)(de)(de)能耗(hao)(hao)。交流(liu)-直流(liu)（AC-DC）電(dian)(dian)(dian)(dian)(dian)源(yuan)空(kong)載(zai)條件(jian)下輸入能耗(hao)(hao)的(de)(de)(de)(de)(de)其中(zhong)一項主(zhu)要來源(yuan)是X2電(dian)(dian)(dian)(dian)(dian)容放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)。典型適配器包含高壓(ya)(ya)X2電(dian)(dian)(dian)(dian)(dian)容，它連接(jie)至交流(liu)輸入端(duan)，作為電(dian)(dian)(dian)(dian)(dian)磁(ci)干擾（EMI）濾波器的(de)(de)(de)(de)(de)一部(bu)分。出于安(an)全(quan)原因，強制要求(qiu)此電(dian)(dian)(dian)(dian)(dian)容在(zai)(zai)從墻上拔出適配器插(cha)頭后(hou)的(de)(de)(de)(de)(de)1秒(miao)時間內(nei)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)至安(an)全(quan)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)平(ping)。否則(ze)，接(jie)觸交流(liu)插(cha)頭的(de)(de)(de)(de)(de)扁腳（prong）就面臨(lin)電(dian)(dian)(dian)(dian)(dian)擊的(de)(de)(de)(de)(de)危險。符合此要求(qiu)的(de)(de)(de)(de)(de)標準方法是使(shi)用一串與電(dian)(dian)(dian)(dian)(dian)容并聯的(de)(de)(de)(de)(de)高阻(zu)(zu)抗泄放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)。當(dang)(dang)用于230 Vac應用時，這(zhe)恒定的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)型消耗(hao)(hao)源(yuan)約消耗(hao)(hao)25 mW輸入能耗(hao)(hao)。當(dang)(dang)顧及到(dao)空(kong)載(zai)能耗(hao)(hao)時，這(zhe)25 mW就變(bian)得相當(dang)(dang)大了(le)。NCP1246解(jie)決此問題(ti)的(de)(de)(de)(de)(de)方法是加(jia)入帶(dai)有源(yuan)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)的(de)(de)(de)(de)(de)內(nei)置(zhi)交流(liu)線路(lu)(lu)(lu)檢(jian)測(ce)器。這(zhe)控制器在(zai)(zai)檢(jian)測(ce)到(dao)不再(zai)存(cun)在(zai)(zai)交流(liu)信號時，激活內(nei)置(zhi)開關(guan)來使(shi)電(dian)(dian)(dian)(dian)(dian)容放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)。有了(le)這(zhe)個(ge)功能，就不再(zai)需要泄放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)了(le)，消除了(le)恒定的(de)(de)(de)(de)(de)25 mW能耗(hao)(hao)源(yuan)頭。

　　次級端(duan)(duan)開關(guan)(guan)電(dian)(dian)(dian)源(yuan)(yuan)控(kong)制(zhi)器(qi)（即安(an)森(sen)美半導體的NCP4354）是NCP1246的伴侶(lv)IC,能(neng)(neng)(neng)夠(gou)檢測空(kong)載條件，并(bing)使電(dian)(dian)(dian)源(yuan)(yuan)進入低能(neng)(neng)(neng)耗(hao)關(guan)(guan)閉模式。在(zai)關(guan)(guan)閉模式期(qi)間，初級端(duan)(duan)控(kong)制(zhi)器(qi)停止(zhi)工作，能(neng)(neng)(neng)量由輸(shu)(shu)出(chu)電(dian)(dian)(dian)容提(ti)供。適(shi)(shi)配(pei)器(qi)的輸(shu)(shu)出(chu)電(dian)(dian)(dian)壓(ya)開始下降，因(yin)為(wei)初級端(duan)(duan)不再(zai)在(zai)存(cun)在(zai)開關(guan)(guan)工作。這并(bing)不構成什么問題，因(yin)為(wei)適(shi)(shi)配(pei)器(qi)在(zai)此(ci)模式下不再(zai)連接至筆記本電(dian)(dian)(dian)腦。輸(shu)(shu)出(chu)電(dian)(dian)(dian)壓(ya)被允許下降至某個可調節電(dian)(dian)(dian)平，直到NCP4354通(tong)知初級端(duan)(duan)重(zhong)啟(qi)，重(zhong)新(xin)(xin)為(wei)輸(shu)(shu)出(chu)電(dian)(dian)(dian)容充電(dian)(dian)(dian)并(bing)因(yin)此(ci)維持工作。當適(shi)(shi)配(pei)器(qi)重(zhong)新(xin)(xin)連接至電(dian)(dian)(dian)池(chi)時(shi)，NCP4354控(kong)制(zhi)器(qi)自(zi)動(dong)重(zhong)啟(qi)初級端(duan)(duan)控(kong)制(zhi)器(qi)。能(neng)(neng)(neng)僅以一顆光(guang)耦提(ti)供反饋控(kong)制(zhi)及導通(tong)/關(guan)(guan)閉信(xin)號(hao)。當在(zai)此(ci)類電(dian)(dian)(dian)路中一起(qi)使用時(shi)，NCP1246和NCP4354能(neng)(neng)(neng)夠(gou)采用美國規格的交流主電(dian)(dian)(dian)源(yuan)(yuan)提(ti)供低于(yu)10 mW的空(kong)載能(neng)(neng)(neng)耗(hao)，且在(zai)寬交流主電(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)壓(ya)范圍下提(ti)供低于(yu)20 mW的空(kong)載能(neng)(neng)(neng)耗(hao)。

　　圖4:65 W適配器電路圖

　　雖(sui)然許多消費(fei)電(dian)子OEM生產(chan)高能效(xiao)產(chan)品(pin)，但他們常(chang)常(chang)會對低能耗的(de)充(chong)電(dian)系(xi)統(tong)感到失望。如今已經出現重要(yao)進展，電(dian)池充(chong)電(dian)器可(ke)以消耗更少電(dian)能，同(tong)時提供(gong)市場所(suo)要(yao)求的(de)高性(xing)能基準。諸如本文所(suo)介紹的(de)系(xi)統(tong)致力于(yu)滿足這些標準，并降低系(xi)統(tong)復雜度、節省珍貴的(de)電(dian)路板空(kong)間及使(shi)物料單（BOM）成本受到控制。