移動DVD液晶屏驅動電路供電原理分析 移動DVD是如何供電的

原理分析

移(yi)動(dong)(dong)DVD機，受其(qi)體積限制，外(wai)接電(dian)池電(dian)壓(ya)大多為(wei)9V左(zuo)右，但其(qi)液(ye)晶(jing)屏驅(qu)動(dong)(dong)部分，需要多組不同(tong)的電(dian)壓(ya)，因此(ci)移(yi)動(dong)(dong)DVD機液(ye)晶(jing)屏驅(qu)動(dong)(dong)部分的供(gong)電(dian)電(dian)路相對較(jiao)(jiao)為(wei)復雜，故(gu)障率也較(jiao)(jiao)高。附圖(tu)為(wei)新(xin)科SDP1710型移(yi)動(dong)(dong)DVD機液(ye)晶(jing)屏驅(qu)動(dong)(dong)部分電(dian)路圖(tu)。

此電(dian)(dian)(dian)路(lu)為(wei)(wei)液晶屏(ping)驅動供電(dian)(dian)(dian)電(dian)(dian)(dian)路(lu)（又(you)稱(cheng)二(er)次升壓(ya)電(dian)(dian)(dian)路(lu)）。因(yin)彩色TFT顯示屏(ping)播放視頻圖(tu)像(xiang)時(shi)，要(yao)求有快(kuai)速響應時(shi)間(jian)，對(dui)于控制電(dian)(dian)(dian)路(lu)，意(yi)味著要(yao)加(jia)上更高的(de)驅動電(dian)(dian)(dian)壓(ya)；TFT屏(ping)的(de)非晶薄膜晶體管的(de)閾值(zhi)電(dian)(dian)(dian)壓(ya)較高，輸入的(de)信號有的(de)高達(da)20V。而(er)此電(dian)(dian)(dian)壓(ya)作為(wei)(wei)便捷式產品，一般難以達(da)到要(yao)求，故需(xu)要(yao)通過升壓(ya)電(dian)(dian)(dian)路(lu)來變換。

由N106五端(duan)5V穩壓(ya)集成(cheng)(cheng)電(dian)(dian)路(lu)③腳輸出5V電(dian)(dian)壓(ya)，此電(dian)(dian)壓(ya)作(zuo)為(wei)整個(ge)液晶屏(ping)驅(qu)動的輸入電(dian)(dian)壓(ya)（不包括CCFL共電(dian)(dian)）。一路(lu)供升壓(ya)電(dian)(dian)路(lu)；一路(lu)供N112（PU5100）脈寬(kuan)調制集成(cheng)(cheng)電(dian)(dian)路(lu)。

N112的(de)③腳(jiao)加上(shang)5V電(dian)(dian)壓(ya)，經(jing)內(nei)部穩壓(ya)，恒流得(de)到(dao)1.25V的(de)基準電(dian)(dian)壓(ya)，由(you)(you)⑨腳(jiao)輸(shu)出。12腳(jiao)外掛C174為定(ding)時電(dian)(dian)容。R151為定(ding)時電(dian)(dian)阻，其值決定(ding)N112的(de)工作頻(pin)率，①、11腳(jiao)輸(shu)入(ru)的(de)正負反饋(kui)電(dian)(dian)壓(ya)，經(jing)N112內(nei)部誤(wu)差放大、PWM比較等，由(you)(you)④腳(jiao)輸(shu)出受控脈(mo)沖信號(hao)，經(jing)R143控制VD122（BR）開關管。

當(dang)VD122導通(tong)(tong)時(shi)(shi)，對L137蓄積(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。而(er)(er)VD122截止時(shi)(shi)，L137電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)中(zhong)的電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)經(jing)V123二極管（MI）對C182充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)(gong)(gong)(gong)負載能(neng)(neng)量(liang)，周(zhou)而(er)(er)復(fu)始(shi)。V1電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)為(wei)-14V，調節N112①腳(jiao)(jiao)外接(jie)反(fan)饋電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R140阻(zu)值(zhi)(zhi)可(ke)改(gai)變(bian)其輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)；⑩腳(jiao)(jiao)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，與(yu)來自15腳(jiao)(jiao)的反(fan)饋電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)N112內(nei)部誤差放大(da)，PWM比(bi)較等，經(jing)⑤腳(jiao)(jiao)輸(shu)出(chu)一(yi)個受控的脈(mo)沖信號，經(jing)R146控制VD127（IR）開關管，當(dang)VD127導通(tong)(tong)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)流從(cong)(cong)L131電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)經(jing)集(ji)電(dian)(dian)(dian)(dian)(dian)(dian)極到(dao)發(fa)射(she)極形成回路，從(cong)(cong)而(er)(er)在(zai)L13l中(zhong)蓄積(ji)(ji)能(neng)(neng)量(liang)。而(er)(er)VD127截止時(shi)(shi)，L131電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)中(zhong)的能(neng)(neng)量(liang)經(jing)VD128（MI）對C181電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)(gong)(gong)(gong)負載能(neng)(neng)量(liang)周(zhou)而(er)(er)復(fu)始(shi)工(gong)作。V2電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)為(wei)13.6V，調節R144阻(zu)值(zhi)(zhi)可(ke)改(gai)變(bian)其輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)；由(you)⑩腳(jiao)(jiao)輸(shu)入的基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，與(yu)來自14腳(jiao)(jiao)的反(fan)饋電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)N112內(nei)部誤差放大(da)，PWM比(bi)較等。經(jing)⑥腳(jiao)(jiao)輸(shu)出(chu)一(yi)個受控的脈(mo)沖信號，經(jing)R145控制VD125（IR）開關管，當(dang)VD125導通(tong)(tong)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)流從(cong)(cong)L132電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)經(jing)集(ji)電(dian)(dian)(dian)(dian)(dian)(dian)極到(dao)發(fa)射(she)極形成回路，從(cong)(cong)而(er)(er)在(zai)L132電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)中(zhong)蓄積(ji)(ji)能(neng)(neng)量(liang)，VD125截止時(shi)(shi)L132電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)(gan)(gan)中(zhong)的能(neng)(neng)量(liang)經(jing)VD126二極管（MI）對C124電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)(gong)(gong)(gong)負載能(neng)(neng)量(liang)周(zhou)而(er)(er)復(fu)始(shi)工(gong)作。V3電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)為(wei)7.5V，調節14腳(jiao)(jiao)外接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R152阻(zu)值(zhi)(zhi)，可(ke)改(gai)變(bian)其輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)(zhi)。V1、V2、V3電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)主要(yao)作為(wei)方波放大(da)電(dian)(dian)(dian)(dian)(dian)(dian)路供(gong)(gong)(gong)(gong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)源。