當今科技所需求的(de)手(shou)機(ji)電(dian)(dian)池除(chu)了要能夠長(chang)時間(jian)供應穩定電(dian)(dian)源外,體積小重量(liang)輕也是(shi)關鍵。縮小電(dian)(dian)路板(ban)面積、增長(chang)供電(dian)(dian)時間(jian)與減少成本該(gai)如何(he)畢(bi)其功于一(yi)役？將眾多電(dian)(dian)源管(guan)理組件整合在單一(yi)芯片上(shang)將是(shi)解決(jue)問題的(de)最(zui)好途徑(jing)。

    早期的(de)(de)行(xing)動(dong)電(dian)(dian)(dian)話(hua)不是(shi)體(ti)積笨(ben)重龐大(da),就是(shi)必須受到汽車電(dian)(dian)(dian)池的(de)(de)束縛,但經過(guo)長時間的(de)(de)發展(zhan),今天的(de)(de)行(xing)動(dong)電(dian)(dian)(dian)話(hua)已變得非常(chang)輕(qing)巧,除了電(dian)(dian)(dian)話(hua)功能,它(ta)(ta)(ta)們(men)還會做(zuo)許多事。新型3.xG智能型手機(ji)把傳統(tong)的(de)(de)2G行(xing)動(dong)電(dian)(dian)(dian)話(hua)和(he)多種其它(ta)(ta)(ta)功能結合(he)在(zai)一起(qi),包括PDA、數字相(xiang)機(ji)、音(yin)樂播放機(ji)（MP3）以及全(quan)球定位系統(tong)（GPS）。如此多元的(de)(de)功能需(xu)要許多零件,其中絕大(da)多數的(de)(de)電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)壓并不相(xiang)同(tong),電(dian)(dian)(dian)流需(xu)求則不斷增加,使得它(ta)(ta)(ta)們(men)需(xu)要更多電(dian)(dian)(dian)力(li)。(圖(tu)一)是(shi)從2G語(yu)音(yin)電(dian)(dian)(dian)話(hua)升級到3G視(shi)訊(xun)電(dian)(dian)(dian)話(hua)后(hou),功率(lv)需(xu)求增加的(de)(de)估(gu)計值。

 

 

    圖一功耗值(zhi)

    在(zai)此(ci)同時(shi),消費者卻(que)想要更(geng)(geng)精巧的(de)手機。本文(wen)介紹兩種(zhong)電源(yuan)管理(li)系統,它們可以(yi)協助智能(neng)型手機設計(ji)人員在(zai)彼此(ci)沖突(tu)的(de)目標間(jian)取得平衡(heng),例如將(jiang)封裝減至最(zui)(zui)小,同時(shi)支持更(geng)(geng)大的(de)功率(lv)需求;實現最(zui)(zui)佳(jia)效率(lv),讓電池提供最(zui)(zui)長的(de)使用時(shi)間(jian);以(yi)及將(jiang)電源(yuan)噪聲和漣波(bo)降至可接(jie)受水平,以(yi)支持新世(shi)代的(de)行動電話。

    選擇電池(chi)

    選擇充電電池是電源管理系統設計的首要工作之一,鎳氫電池和鋰離子電池則是目(mu)前僅有的(de)(de)兩種實(shi)際選擇(ze)。鋰離子電(dian)(dian)(dian)(dian)池的(de)(de)單(dan)位體(ti)積蓄(xu)電(dian)(dian)(dian)(dian)量(liang)(liang)為270～300Wh/l,單(dan)位重(zhong)量(liang)(liang)蓄(xu)電(dian)(dian)(dian)(dian)量(liang)(liang)為110～130Wh/kg,都(dou)高于(yu)鎳(nie)氫電(dian)(dian)(dian)(dian)池的(de)(de)220～300Wh/l以及75～100Wh/kg,因此在同樣蓄(xu)電(dian)(dian)(dian)(dian)量(liang)(liang)下,鋰離子電(dian)(dian)(dian)(dian)池的(de)(de)體(ti)積和(he)重(zhong)量(liang)(liang)都(dou)小于(yu)鎳(nie)氫電(dian)(dian)(dian)(dian)池;另(ling)外,鋰離子電(dian)(dian)(dian)(dian)池的(de)(de)3.6V工作電(dian)(dian)(dian)(dian)壓也高于(yu)鎳(nie)氫電(dian)(dian)(dian)(dian)池的(de)(de)1.2V。

    行(xing)動電話的多(duo)數功耗都來自(zi)于(yu)1.2V和3.3V電源,要讓交換式電源轉(zhuan)換器發揮最大工作效(xiao)率,較有效(xiao)的方(fang)法通常(chang)是從(cong)高電壓(ya)轉(zhuan)換至低電壓(ya),而不(bu)是從(cong)低電壓(ya)轉(zhuan)換至高電壓(ya),因此鋰離(li)子電池是最佳選擇。

    要讓充電電池提供最長使用時間,適當的電池管理和控制就顯得格外重要。電池管理包含三個部份：充電控制、電池監視和電池保護。從使用外接導通組件的線性控制器開始,到內建開關組件且效率更高的交換式控制器,充電控制組件已有長足進步。電池充電器必須處理(li)500mA到1500mA范圍內的電(dian)流,以便提供快速的充電(dian)周期時間。

    電(dian)(dian)(dian)池(chi)監視和保護組件(jian)通常(chang)都與電(dian)(dian)(dian)池(chi)封(feng)裝在(zai)一起,電(dian)(dian)(dian)池(chi)監視組件(jian)可以是簡(jian)單的「電(dian)(dian)(dian)荷計量(liang)器(qi)」（coulombcounter）,由中央處理器(qi)負責計算電(dian)(dian)(dian)池(chi)剩余(yu)電(dian)(dian)(dian)力;也可以是內建微(wei)控制器(qi)的電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)力量(liang)測組件(jian)（gasgauge）,由它透過(guo)DSP與處理器(qi)之(zhi)間的簡(jian)單界面,直接提供剩余(yu)電(dian)(dian)(dian)力、剩余(yu)供電(dian)(dian)(dian)時間、電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓、溫(wen)度和平(ping)均電(dian)(dian)(dian)流量(liang)測值等資料。

    電源拓樸

    接(jie)著,設計工程師必(bi)須(xu)決定(ding)電(dian)(dian)(dian)(dian)源(yuan)轉(zhuan)換(huan)(huan)組件(jian)的種類(lei),它或許是以(yi)(yi)電(dian)(dian)(dian)(dian)感為(wei)基(ji)礎、并且內建FET開(kai)關(guan)的交(jiao)(jiao)換(huan)(huan)式(shi)電(dian)(dian)(dian)(dian)源(yuan)轉(zhuan)換(huan)(huan)器(qi)(qi)、無(wu)電(dian)(dian)(dian)(dian)感的交(jiao)(jiao)換(huan)(huan)式(shi)電(dian)(dian)(dian)(dian)源(yuan)轉(zhuan)換(huan)(huan)器(qi)(qi)（電(dian)(dian)(dian)(dian)荷(he)(he)泵浦(pu)）或是線(xian)(xian)性(xing)穩壓器(qi)(qi)。這些轉(zhuan)換(huan)(huan)器(qi)(qi)各有其優點(dian)。就效(xiao)率而言,以(yi)(yi)電(dian)(dian)(dian)(dian)感為(wei)基(ji)礎的轉(zhuan)換(huan)(huan)器(qi)(qi)擁有最(zui)(zui)高的整體效(xiao)率,其次是電(dian)(dian)(dian)(dian)荷(he)(he)泵浦(pu),最(zui)(zui)后才是線(xian)(xian)性(xing)穩壓器(qi)(qi)。成本(ben)通常反比(bi)于效(xiao)率,因(yin)此線(xian)(xian)性(xing)穩壓器(qi)(qi)成本(ben)最(zui)(zui)低(di),然(ran)后是電(dian)(dian)(dian)(dian)荷(he)(he)泵浦(pu),最(zui)(zui)后則是以(yi)(yi)電(dian)(dian)(dian)(dian)感為(wei)基(ji)礎的轉(zhuan)換(huan)(huan)器(qi)(qi)。

  線(xian)性穩(wen)壓器(qi)(qi)沒有(you)輸(shu)出(chu)(chu)漣波(bo),電(dian)(dian)(dian)荷泵浦有(you)一些(xie)輸(shu)出(chu)(chu)漣波(bo),交換式穩(wen)壓器(qi)(qi)的輸(shu)出(chu)(chu)漣波(bo)則在三者之間(jian)最高。就整個(ge)解決方案(an)的體(ti)(ti)積來(lai)看,線(xian)性穩(wen)壓器(qi)(qi)的體(ti)(ti)積最小,通常(chang)只(zhi)需(xu)(xu)輸(shu)入(ru)和輸(shu)出(chu)(chu)電(dian)(dian)(dian)容(rong)(rong),電(dian)(dian)(dian)荷泵浦除了輸(shu)入(ru)和輸(shu)出(chu)(chu)電(dian)(dian)(dian)容(rong)(rong)外,還需(xu)(xu)一顆或(huo)兩顆「飛(fei)馳」（flying）電(dian)(dian)(dian)容(rong)(rong),交換式穩(wen)壓器(qi)(qi)則需(xu)(xu)要電(dian)(dian)(dian)感器(qi)(qi),因此其(qi)封裝體(ti)(ti)積會(hui)有(you)很大(da)差(cha)異(yi)。

    無論DSP或模擬數字轉(zhuan)(zhuan)換器(qi)等(deng)數字零(ling)件(jian),或是(shi)電(dian)(dian)源管(guan)理(li)系統(tong)等(deng)模擬零(ling)件(jian),2G電(dian)(dian)話幾(ji)乎不提供任何的(de)功能(neng)整合,系統(tong)設計人員在發展電(dian)(dian)源管(guan)理(li)系統(tong)時(shi),通常會以(yi)成本和體積為(wei)優先考慮,而不是(shi)轉(zhuan)(zhuan)換效(xiao)率。線性穩壓器(qi)只能(neng)將輸(shu)入電(dian)(dian)壓轉(zhuan)(zhuan)換成更(geng)低(di)的(de)輸(shu)出電(dian)(dian)壓,因此(ci)電(dian)(dian)池電(dian)(dian)壓必須高于3.3V,此(ci)時(shi)可利用低(di)電(dian)(dian)流或中電(dian)(dian)流的(de)線性穩壓器(qi)進行電(dian)(dian)壓轉(zhuan)(zhuan)換,以(yi)便提供電(dian)(dian)力給至2.8V范圍內的(de)其它電(dian)(dian)源需求。

    在3G芯片(pian)組中,基頻處(chu)理(li)器(qi)(qi)(qi)(qi)(qi)現已包含DSP、微(wei)處(chu)理(li)器(qi)(qi)(qi)(qi)(qi)／微(wei)控制器(qi)(qi)(qi)(qi)(qi)、模擬數(shu)字(zi)轉換器(qi)(qi)(qi)(qi)(qi)和數(shu)字(zi)模擬轉換器(qi)(qi)(qi)(qi)(qi),用(yong)(yong)來控制射頻訊號(hao)和音(yin)頻訊號(hao)處(chu)理(li)。這顆(ke)處(chu)理(li)器(qi)(qi)(qi)(qi)(qi)的核心電(dian)(dian)壓(ya)已降至1.2V或(huo)是(shi)更低,I/O和外圍電(dian)(dian)壓(ya)也開始減(jian)少(shao)至2.5V至3.0V范圍;由于3.xG電(dian)(dian)話的電(dian)(dian)流需求(qiu)通常都(dou)超過(guo)2.G電(dian)(dian)話,3.xG設(she)計(ji)人(ren)員需要效率高于線(xian)性穩壓(ya)器(qi)(qi)(qi)(qi)(qi)的直(zhi)流電(dian)(dian)源轉換器(qi)(qi)(qi)(qi)(qi),以便提供更長的電(dian)(dian)池(chi)使(shi)用(yong)(yong)時間(jian)。為進一(yi)步(bu)延長電(dian)(dian)池(chi)壽命,許多設(she)計(ji)人(ren)員必(bi)須(xu)盡量利用(yong)(yong)鋰離子(zi)電(dian)(dian)池(chi)電(dian)(dian)力,直(zhi)到其電(dian)(dian)壓(ya)降至最小值為止;在此(ci)過(guo)程中,如何產生3.3V電(dian)(dian)壓(ya)就變(bian)成一(yi)項挑(tiao)戰(zhan)。

    從表面上來看,設計人員若(ruo)能繼續使(shi)用電(dian)(dian)(dian)池(chi)直到2.7V,并利用正電(dian)(dian)(dian)源(yuan)降壓―升壓轉(zhuan)換(huan)(huan)器(qi)(qi)或(huo)是(shi)SEPIC轉(zhuan)換(huan)(huan)器(qi)(qi)提供3.3V電(dian)(dian)(dian)源(yuan),可攜式裝(zhuang)置(zhi)的(de)(de)電(dian)(dian)(dian)池(chi)壽命就會大幅延(yan)長,但(dan)是(shi)根(gen)據(表一)針對600mAh電(dian)(dian)(dian)池(chi)所做(zuo)的(de)(de)簡單(dan)分析可發現情(qing)形并非(fei)如此,因(yin)為無論是(shi)采用效率更高(gao)的(de)(de)降壓轉(zhuan)換(huan)(huan)器(qi)(qi),并將電(dian)(dian)(dian)池(chi)使(shi)用到3.3V,或(huo)是(shi)采用SEPIC之類的(de)(de)轉(zhuan)換(huan)(huan)器(qi)(qi),并將電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)力完(wan)全用盡,這兩種(zhong)方式的(de)(de)供電(dian)(dian)(dian)時間(jian)幾乎沒有任何區別。

    

 

    表一(yi)60mAh電池(chi)分析

    除此之外,無(wu)論是(shi)使用兩顆電(dian)感的(de)SEPIC轉(zhuan)(zhuan)換(huan)器(qi),或是(shi)某(mou)些效(xiao)率(lv)更(geng)高的(de)新型正(zheng)電(dian)源降壓―升壓轉(zhuan)(zhuan)換(huan)器(qi),它們的(de)成本都更(geng)高,因(yin)此在(zai)做整體評估時,只使用3.3V以上的(de)電(dian)池電(dian)力(li),然后利用高效(xiao)率(lv)交(jiao)換(huan)式(shi)電(dian)源轉(zhuan)(zhuan)換(huan)器(qi)提供(gong)3.3V電(dian)源的(de)方法不(bu)但更(geng)有效(xiao)率(lv),還(huan)可能是(shi)更(geng)具吸引(yin)力(li)的(de)選擇。以下介紹的(de)離(li)散解(jie)決方案(an)就是(shi)使用降壓轉(zhuan)(zhuan)換(huan)器(qi)提供(gong)3.3V電(dian)源,整合式(shi)解(jie)決方案(an)則采用SEPIC轉(zhuan)(zhuan)換(huan)器(qi)。

   系統(tong)概述

    不(bu)(bu)同(tong)的(de)智能型(xing)手機零件有(you)著不(bu)(bu)同(tong)的(de)電源(yuan)(yuan)需(xu)求(qiu),(圖二(er))是行動電話中(zhong)(zhong)需(xu)要(yao)電源(yuan)(yuan)的(de)主要(yao)零件簡單(dan)方塊(kuai)圖,例(li)如射頻單(dan)元的(de)壓控(kong)振蕩器(qi)（VCO）以(yi)及鎖相(xiang)回路（PLL）就需(xu)要(yao)極低噪(zao)聲和很高電源(yuan)(yuan)拒斥比的(de)電源(yuan)(yuan),確保它們(men)提供(gong)最高的(de)傳送和接收效(xiao)(xiao)能,因(yin)此(ci)雖然線性穩壓器(qi)的(de)效(xiao)(xiao)率(lv)不(bu)(bu)高,但(dan)由于它沒有(you)輸出漣(lian)波(bo),所以(yi)是這類(lei)電源(yuan)(yuan)供(gong)應的(de)最佳選擇;同(tong)樣重要(yao)的(de)是將直流轉換器(qi)的(de)開關頻率(lv),還有(you)它們(men)的(de)二(er)階和三階諧波(bo),都保持在(zai)中(zhong)(zhong)頻頻帶之外。

    由于(yu)DSP和中央處理器(qi)的(de)核心電(dian)(dian)壓已降(jiang)至1V左(zuo)右,以電(dian)(dian)感為(wei)基礎(chu)的(de)高效率(lv)交換式降(jiang)壓轉換器(qi)是理想選擇。至于(yu)屏幕背光照明所使用的(de)白光二極管(guan),其(qi)電(dian)(dian)源可來自電(dian)(dian)荷泵浦或(huo)電(dian)(dian)感式升壓／降(jiang)壓轉換器(qi)。

    圖二智能型手機電源方塊(kuai)圖

    動態電壓調(diao)整（DynamicVoltageScaling）

    從圖(tu)一可(ke)看出,電源需求最高(gao)的(de)兩顆零件是(shi)在(zai)(zai)射頻(pin)單元,分(fen)別是(shi)發(fa)(fa)射機的(de)功(gong)率(lv)放(fang)(fang)大(da)器和基頻(pin)處理器。隨著電話與基地臺(tai)之(zhi)間(jian)(jian)的(de)距(ju)離不同,功(gong)率(lv)放(fang)(fang)大(da)器在(zai)(zai)通(tong)話過程中(zhong)最多消耗(hao)75％的(de)總功(gong)耗(hao),待命模式則只(zhi)有30％。采用非線(xian)性功(gong)率(lv)放(fang)(fang)大(da)器的(de)舊型GSM電話發(fa)(fa)射機的(de)典(dian)型工作(zuo)效率(lv)約為50％,但(dan)是(shi)WCDMA等較新標(biao)準(zhun)卻(que)同時需要振(zhen)幅及相位調變(bian),這只(zhi)有工作(zuo)效率(lv)在(zai)(zai)25％至(zhi)35％之(zhi)間(jian)(jian)的(de)線(xian)性放(fang)(fang)大(da)器可(ke)以提(ti)供。

    除此之外,CDMA20001x手機的(de)正常(chang)基(ji)頻處(chu)(chu)理器(qi)負(fu)載需求是(shi)在(zai)60至120mA范圍(wei),因此提(ti)供(gong)最有效率(lv)的(de)電源給功率(lv)放大器(qi)和處(chu)(chu)理器(qi)就顯得(de)極為重(zhong)要(yao)。

    動態(tai)／可適性電(dian)(dian)壓(ya)調整(zheng)(zheng)技術（DVS/AVS）與高(gao)整(zheng)(zheng)合度組件所使用的(de)(de)方(fang)式很(hen)類(lei)似,它會(hui)把閉回路系統(tong)中的(de)(de)處(chu)理器和穩壓(ya)器連結在(zai)一起,并在(zai)確保系統(tong)正常工作(zuo)(zuo)(zuo)的(de)(de)情形下(xia),將數(shu)字電(dian)(dian)源供應的(de)(de)輸出電(dian)(dian)壓(ya)動態(tai)調整(zheng)(zheng)至最(zui)小值。功(gong)(gong)(gong)率(lv)(lv)放大器會(hui)被最(zui)佳化,使它在(zai)最(zui)大傳送功(gong)(gong)(gong)率(lv)(lv)下(xia)擁有(you)最(zui)高(gao)效(xiao)(xiao)率(lv)(lv)。由于絕大多數(shu)手機都(dou)在(zai)基地臺附近工作(zuo)(zuo)(zuo),手機的(de)(de)無線(xian)電(dian)(dian)功(gong)(gong)(gong)能會(hui)在(zai)維持通訊質量的(de)(de)前題(ti)下(xia),將傳送功(gong)(gong)(gong)率(lv)(lv)降至最(zui)低(di)水平。當功(gong)(gong)(gong)率(lv)(lv)放大器在(zai)較(jiao)低(di)的(de)(de)功(gong)(gong)(gong)率(lv)(lv)水平下(xia)工作(zuo)(zuo)(zuo)時,它的(de)(de)效(xiao)(xiao)率(lv)(lv)會(hui)受到影響(xiang),從(圖三)可以看出,利用動態(tai)電(dian)(dian)壓(ya)調整(zheng)(zheng)技術來調整(zheng)(zheng)功(gong)(gong)(gong)率(lv)(lv)放大器的(de)(de)電(dian)(dian)壓(ya),它的(de)(de)工作(zuo)(zuo)(zuo)效(xiao)(xiao)率(lv)(lv)會(hui)增加10％至20％。

 

    圖三功率(lv)放(fang)大器效(xiao)率(lv)

    數字處理(li)器的功耗(hao)正比于電壓平方,因此(ci)中(zhong)央(yang)(yang)處理(li)器也能(neng)采用動(dong)態電壓調整技術;當(dang)中(zhong)央(yang)(yang)處理(li)器進入待命模(mo)式或其它(ta)功能(neng)精(jing)簡(jian)模(mo)式,它(ta)就能(neng)在較低的頻率(lv)頻率(lv)下工(gong)作,此(ci)時(shi)可將處理(li)器電壓降低,以便減少功耗(hao),提升工(gong)作效率(lv),延(yan)長電池壽(shou)命。

    就以OMAP1510為(wei)例,假設(she)它(ta)的電源是由TPS62200供應,并(bing)使用1安培小(xiao)時的3.6V鋰離子電池輸入,其它(ta)特(te)性包括：

    ●睡眠模式（TPS62200采用(yong)PFM調變）未(wei)用(yong)動態電(dian)壓調整：Vout=1.5V@300μA;效率=93％

    ●正(zheng)常工(gong)作模式（TPS62200采用PWM調變(bian)）：Vout=1.5V@100mA;效率=96％

    假設(she)此(ci)組件95％時(shi)間(jian)處于睡眠模(mo)式,5％時(shi)間(jian)處于正常工(gong)作模(mo)式,則從輸出(chu)功(gong)率與時(shi)間(jian)的關系圖(tu)可看出(chu),將動(dong)態電壓(ya)調整技(ji)術用于睡眠模(mo)式,電池(chi)壽命(ming)會最多(duo)延長9個(ge)小(xiao)時(shi)。

離散解決方案

    (圖四)是利用離散組(zu)件(jian)實作的電(dian)源管(guan)理系統,電(dian)池電(dian)壓(ya)限(xian)制為3.3V。

    圖四(si)利(li)用離散(san)組件(jian)實作的(de)電源管理系統

    在這(zhe)個解決方案中(zhong),就算鋰離(li)子電(dian)(dian)池下降(jiang)至3.3V左右,在100％負載周(zhou)期模式(shi)下工作的高(gao)效率(lv)(lv)TPS62200降(jiang)壓(ya)轉換(huan)器仍能(neng)提(ti)供3.3V的I/O電(dian)(dian)壓(ya)。上述所有(you)零件都采(cai)用SOT-23封裝(zhuang),除了(le)bq24020電(dian)(dian)池充電(dian)(dian)組件、TPS61020升壓(ya)轉換(huan)器以及TPS61042白(bai)光二極管驅動(dong)組件之外,它們是采(cai)用3×3平方厘米的QFN封裝(zhuang)。TPS61040和(he)TPS61042還內建(jian)上端FET晶體(ti)管,每(mei)顆(ke)(ke)組件只需要一個外接二極管。bq24020、TPS622xx、TPS61020和(he)線性穩壓(ya)器組件全都內建(jian)FET晶體(ti)管,功率(lv)(lv)放大器和(he)中(zhong)央處理器電(dian)(dian)源采(cai)用的動(dong)態(tai)電(dian)(dian)壓(ya)調整技術可以提(ti)高(gao)每(mei)顆(ke)(ke)零件的效率(lv)(lv),進而協助降(jiang)低功耗。

    整合解決方案

    最(zui)新制(zhi)程(cheng)技術(shu)使得工程(cheng)師更容易結合(he)、迅速修改以及／或是(shi)利用現有的(de)(de)(de)(de)離(li)散組(zu)(zu)件設計(ji),以便提供不同整合(he)程(cheng)度(du)的(de)(de)(de)(de)半(ban)導體芯片,例如(ru)通用的(de)(de)(de)(de)雙通道交(jiao)換(huan)(huan)式(shi)轉換(huan)(huan)器和電源拒斥比很高而噪聲很低的(de)(de)(de)(de)雙信道線性(xing)穩壓(ya)器、特殊(shu)應用白光二極管的(de)(de)(de)(de)電源供應以及行動電話、PDA和數字相機的(de)(de)(de)(de)多電源管理解(jie)決方案(an),這(zhe)些產品都(dou)已(yi)開始供應。專門支持終端設備的(de)(de)(de)(de)電源組(zu)(zu)件則(ze)會內建(jian)各(ge)種外圍,其范圍從行動電話的(de)(de)(de)(de)響鈴(ling)器和蜂鳴器到PDA的(de)(de)(de)(de)通用I/O接腳,例如(ru)圖四整合(he)解(jie)決方案(an)所使用的(de)(de)(de)(de)TPS65010就是(shi)這(zhe)類組(zu)(zu)件。

 

    圖(tu)五整合式解決方(fang)案

    在此解決方案中,3.3VI/O電源是由SEPIC轉換器提供,它讓應用系統能充份利用鋰離子電池電(dian)力,直(zhi)到(dao)電(dian)池電(dian)壓(ya)降(jiang)至最(zui)低水(shui)平（大(da)約2.7V）。和離散解決方案(an)一樣,穩(wen)壓(ya)器輸出也來自3.3V輸入(ru)電(dian)源(yuan),以便提高工(gong)作(zuo)效(xiao)率(lv)。TPS65010采用(yong)(yong)48只接腳QFN封裝(zhuang),這些組件都內(nei)建FET晶體管。TPS61130SEPIC轉換器采用(yong)(yong)4×4平方厘米QFN封裝(zhuang),并且內(nei)建FET晶體管,最(zui)高達到(dao)90％以上效(xiao)率(lv),TPS5100則(ze)是三通道輸出控制器,專門用(yong)(yong)來提供電(dian)源(yuan)給顯(xian)示器。功率(lv)放大(da)器和中(zhong)央處理器電(dian)源(yuan)使用(yong)(yong)的動態電(dian)壓(ya)調整技(ji)術可以改善每顆零件的效(xiao)率(lv),進而(er)協助降(jiang)低功耗。

    離散或整合？

    如(ru)何在離(li)(li)(li)散或整合解決方案之(zhi)(zhi)間(jian)(jian)做出抉擇？一般說來,整合組件(jian)的(de)(de)(de)成本會低于同樣(yang)等級的(de)(de)(de)多(duo)顆(ke)(ke)離(li)(li)(li)散零(ling)件(jian);除此之(zhi)(zhi)外(wai),如(ru)同(圖六)的(de)(de)(de)電(dian)路(lu)(lu)板布局所示,相較于執行同樣(yang)功(gong)能(neng)的(de)(de)(de)多(duo)顆(ke)(ke)離(li)(li)(li)散零(ling)件(jian),TPS65010以及與其(qi)搭配的(de)(de)(de)被(bei)動零(ling)件(jian)只需(xu)(xu)較少的(de)(de)(de)電(dian)路(lu)(lu)板空(kong)間(jian)(jian),這(zhe)主要是因(yin)為離(li)(li)(li)散零(ling)件(jian)之(zhi)(zhi)間(jian)(jian)需(xu)(xu)要額外(wai)空(kong)間(jian)(jian)來容納訊號線路(lu)(lu)。由于TPS65010還包含原來由離(li)(li)(li)散零(ling)件(jian)提供的(de)(de)(de)其(qi)它(ta)功(gong)能(neng),例如(ru)電(dian)源供應順(shun)序(xu)、振動器和二極管驅(qu)動組件(jian),因(yin)此整合解決方案可以節省更(geng)多(duo)電(dian)路(lu)(lu)板面積。

  

 

 

    圖六TPS65010與同等(deng)級離散解決方案的電路板(ban)布比(bi)較

    整(zheng)(zheng)合組(zu)件過去主要(yao)支持(chi)特殊應用(yong),彈(dan)性也(ye)不(bu)是很高,因此(ci)在(zai)設(she)計(ji)流程后(hou)期,它們就(jiu)無法再(zai)進(jin)行(xing)重大的設(she)計(ji)變(bian)更(geng)。然而(er)新的制程技(ji)術,包括支持(chi)可(ke)程序輸出電(dian)壓(ya)(ya)以(yi)(yi)及封裝后(hou)調整(zheng)(zheng)的整(zheng)(zheng)合式EEPROM,卻(que)使得工(gong)程師(shi)能以(yi)(yi)更(geng)低(di)成本,更(geng)簡單(dan)快(kuai)速(su)的對現(xian)有組(zu)件（也(ye)就(jiu)是不(bu)同固定輸出電(dian)壓(ya)(ya)的組(zu)件）重復進(jin)行(xing)簡單(dan)修改。另(ling)一(yi)方(fang)面,整(zheng)(zheng)合組(zu)件的供貨(huo)商(shang)通常只有一(yi)家,這可(ke)能迫使廠商(shang)必須采(cai)用(yong)離(li)散解決方(fang)案。

    未來挑(tiao)戰

    消(xiao)費(fei)者想(xiang)要操作時間(jian)更(geng)長的(de)智能型手機,新發展的(de)半導體(ti)制程(cheng)技術已能減少(shao)泄漏電流(liu)和(he)阻抗（有時透過銅覆(fu)蓋(gai)層）,使得FET晶體(ti)管(guan)的(de)靜態電流(liu)更(geng)低,導通阻抗也變得更(geng)小(xiao)。然而不(bu)同于持續進步中的(de)半導體(ti)技術,電池技術卻沒有任何(he)重(zhong)大進展,無法在(zai)不(bu)增加(jia)電池體(ti)積(ji)的(de)情形下(xia)延長供電時間(jian)。

    電(dian)(dian)(dian)(dian)(dian)容(rong)器技術(shu)的(de)某些進展使得充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)和電(dian)(dian)(dian)(dian)(dian)容(rong)器之間(jian)的(de)界限日益模糊,許多可攜式產品已開始(shi)使用高(gao)(gao)能(neng)量超級電(dian)(dian)(dian)(dian)(dian)容(rong)器（supercapacitor）,做為消費者(zhe)更換電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)時的(de)暫(zan)時電(dian)(dian)(dian)(dian)(dian)力來源;另外,高(gao)(gao)能(neng)量暨高(gao)(gao)功率的(de)超高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)容(rong)器（ultracapacitor）還能(neng)在(zai)短(duan)時間(jian)內提供很大電(dian)(dian)(dian)(dian)(dian)流,讓電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)不(bu)必(bi)瞬間(jian)供應龐大電(dian)(dian)(dian)(dian)(dian)力,可以延(yan)長電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)使用時間(jian)。這些超高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)容(rong)器會(hui)整合至(zhi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)封裝內,并在(zai)系(xi)統電(dian)(dian)(dian)(dian)(dian)力需求不(bu)太高(gao)(gao)時,利用微(wei)小電(dian)(dian)(dian)(dian)(dian)流充電(dian)(dian)(dian)(dian)(dian)。

    燃(ran)料(liao)電(dian)池(chi)(chi)近來是(shi)熱門話(hua)題,但由于外形包裝(zhuang)尚(shang)未標準化,使得燃(ran)料(liao)電(dian)池(chi)(chi)的廣泛應用受到影(ying)響(xiang),商業化過程也不太順利。燃(ran)料(liao)電(dian)池(chi)(chi)的輸(shu)出(chu)瞬時響(xiang)應也很糟(zao)糕,因此至少(shao)在最(zui)初階段燃(ran)料(liao)電(dian)池(chi)(chi)只會做為普通電(dian)池(chi)(chi)的補強(qiang)裝(zhuang)置,無(wu)法取代普通電(dian)池(chi)(chi)。

    消費(fei)者(zhe)還希望產品(pin)的(de)(de)(de)體積更小,功能(neng)更加強大,創新(xin)的(de)(de)(de)電源管理(li)組件設計以(yi)及(ji)封(feng)(feng)裝和制程(cheng)技(ji)術的(de)(de)(de)進步(bu)都能(neng)幫助實(shi)現此(ci)目(mu)標。日益(yi)精密的(de)(de)(de)制程(cheng)技(ji)術可以(yi)制造出(chu)越來越小的(de)(de)(de)FET晶(jing)體管,讓晶(jing)粒(li)和封(feng)(feng)裝的(de)(de)(de)體積更小,工(gong)作電壓(ya)更低,閘極電容(rong)更少,使得(de)晶(jing)體管的(de)(de)(de)開關速度更快

    ―對于(yu)以電感(gan)(gan)為基礎的(de)交換式電源供應,更(geng)(geng)快的(de)開(kai)關速度意味著(zhu)更(geng)(geng)小的(de)電感(gan)(gan)。新(xin)封裝(zhuang)技術(shu)則能(neng)在(zai)更(geng)(geng)小的(de)封裝(zhuang)中容納(na)更(geng)(geng)多功能(neng),并且承受(shou)更(geng)(geng)大的(de)功耗(hao),例如內建FET開(kai)關的(de)鋰(li)離(li)子電池(chi)線性(xing)充電組(zu)件bq24010就采用(yong)3×3平方厘米的(de)QFN封裝(zhuang),它在(zai)普通室溫(wen)環境下,最高能(neng)承受(shou)1.5W功耗(hao)。

    要在較(jiao)低(di)的(de)(de)工作電(dian)壓(ya)下提(ti)供(gong)更(geng)強(qiang)大功(gong)能,電(dian)源管理單元(yuan)和低(di)噪聲布局的(de)(de)容(rong)忍要求通常(chang)也(ye)會變的(de)(de)更(geng)嚴格,例如系統若要求1.2V電(dian)源的(de)(de)誤差小于(yu)±3%,就(jiu)表示輸出(chu)電(dian)壓(ya)變動(dong)幅度不能超過±36mV;相形(xing)之下,使用3.3V電(dian)源就(jiu)表示在同(tong)樣的(de)(de)±3%誤差限制(zhi)下,它能容(rong)忍的(de)(de)電(dian)壓(ya)變動(dong)高達±99mV。由于(yu)電(dian)源電(dian)壓(ya)不斷降低(di),未來幾年內對(dui)于(yu)誤差更(geng)小、電(dian)流(liu)更(geng)大、效率更(geng)高和電(dian)磁干(gan)擾極低(di)的(de)(de)直(zhi)流(liu)電(dian)源轉換器的(de)(de)需求將會增加。除(chu)此之外,隨著封裝縮小,可供(gong)散熱的(de)(de)面積也(ye)會減(jian)少,讓這些高功(gong)耗組(zu)件的(de)(de)熱管理繼(ji)續成(cheng)為(wei)困難(nan)挑(tiao)戰。

    整合的力(li)量

    本(ben)文介(jie)紹的(de)(de)電(dian)(dian)源(yuan)解決方案使用不同(tong)整合程度的(de)(de)電(dian)(dian)源(yuan)組件(jian)(jian)。把部(bu)份(fen)或全部(bu)的(de)(de)模(mo)擬電(dian)(dian)源(yuan)組件(jian)(jian)和(he)基(ji)(ji)頻(pin)(pin)處(chu)理器等數(shu)字(zi)零件(jian)(jian)整合在一起會(hui)帶(dai)來許多優點,包括節(jie)省更多的(de)(de)電(dian)(dian)路(lu)板面積,并且降低(di)總成(cheng)本(ben)。復雜電(dian)(dian)子系統的(de)(de)每個(ge)部(bu)份(fen)都有著(zhu)不同(tong)的(de)(de)需(xu)求,這是過去(qu)實現更高階數(shu)字(zi)和(he)模(mo)擬零件(jian)(jian)整合的(de)(de)障(zhang)礙之一,例(li)如數(shu)字(zi)基(ji)(ji)頻(pin)(pin)單元需(xu)要(yao)(yao)高密度制程以支(zhi)持(chi)數(shu)字(zi)訊號處(chu)理,模(mo)擬基(ji)(ji)頻(pin)(pin)和(he)電(dian)(dian)源(yuan)功(gong)能需(xu)要(yao)(yao)電(dian)(dian)壓更高的(de)(de)組件(jian)(jian);射頻(pin)(pin)單元,特別是鎖(suo)相回路(lu),則(ze)需(xu)要(yao)(yao)最適合支(zhi)持(chi)高頻(pin)(pin)操(cao)作的(de)(de)BiCMOS組件(jian)(jian)。

    傳(chuan)統上(shang),制程(cheng)發(fa)展是由(you)數字(zi)設計人員負責管(guan)理(li),他們通(tong)常只會(hui)推(tui)動(dong)高密度制程(cheng)發(fa)展,電路(lu)若需(xu)要高電壓(ya)組(zu)件(jian),就(jiu)必須(xu)采用(yong)不(bu)同制程(cheng),這表示(shi)他們需(xu)要獨(du)立的數字(zi)組(zu)件(jian)。半導體廠商不(bu)但(dan)開始發(fa)展「最小閘極長度」更(geng)短的BiCMOS制程(cheng),以便提(ti)供很高的組(zu)件(jian)密度和工作速度,還有更(geng)高電壓(ya)的汲極延伸型組(zu)件(jian)（drainextendeddevices）,它(ta)們已用(yong)于更(geng)多的模(mo)擬(ni)和電源(yuan)應用(yong)。包括電源(yuan)管(guan)理(li)在內的許多模(mo)擬(ni)和數字(zi)功(gong)能最后都(dou)會(hui)整合成單顆芯片(pian)。

    不(bu)(bu)同(tong)程(cheng)度的組(zu)(zu)件整合(he)正在簡化(hua)可(ke)(ke)攜(xie)(xie)式電(dian)源(yuan)設計,尤其是可(ke)(ke)攜(xie)(xie)式產品的系統(tong)設計人員,他們(men)不(bu)(bu)必再擔心組(zu)(zu)件的電(dian)源(yuan)需(xu)求管(guan)理,整合(he)程(cheng)度不(bu)(bu)同(tong)的電(dian)源(yuan)管(guan)理組(zu)(zu)件可(ke)(ke)以幫助他們(men)讓電(dian)池提供最長供電(dian)時間,同(tong)時將(jiang)電(dian)路板面積和成本減至(zhi)最少(shao)。