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

移動DVD機，受其(qi)體積(ji)限制(zhi)，外接電(dian)(dian)池電(dian)(dian)壓(ya)大多(duo)為(wei)9V左右，但其(qi)液晶(jing)(jing)屏驅(qu)(qu)動部(bu)(bu)分(fen)，需要多(duo)組不同(tong)的電(dian)(dian)壓(ya)，因此移動DVD機液晶(jing)(jing)屏驅(qu)(qu)動部(bu)(bu)分(fen)的供電(dian)(dian)電(dian)(dian)路相對較為(wei)復雜，故障率也較高。附(fu)圖為(wei)新科SDP1710型移動DVD機液晶(jing)(jing)屏驅(qu)(qu)動部(bu)(bu)分(fen)電(dian)(dian)路圖。

此(ci)電(dian)(dian)(dian)路為液晶屏驅動(dong)供電(dian)(dian)(dian)電(dian)(dian)(dian)路（又稱二(er)次升(sheng)壓(ya)電(dian)(dian)(dian)路）。因彩色TFT顯(xian)示屏播(bo)放視頻圖像時(shi)，要(yao)求(qiu)有快速響(xiang)應時(shi)間，對于控制電(dian)(dian)(dian)路，意味著要(yao)加(jia)上更高的(de)驅動(dong)電(dian)(dian)(dian)壓(ya)；TFT屏的(de)非晶薄膜晶體(ti)管的(de)閾值電(dian)(dian)(dian)壓(ya)較高，輸入的(de)信號有的(de)高達20V。而此(ci)電(dian)(dian)(dian)壓(ya)作(zuo)為便(bian)捷(jie)式(shi)產品，一般難以(yi)達到要(yao)求(qiu)，故需要(yao)通過(guo)升(sheng)壓(ya)電(dian)(dian)(dian)路來變(bian)換。

由(you)N106五端5V穩壓(ya)(ya)集(ji)成(cheng)電(dian)(dian)路③腳輸出5V電(dian)(dian)壓(ya)(ya)，此電(dian)(dian)壓(ya)(ya)作為整個液晶屏驅動(dong)的輸入電(dian)(dian)壓(ya)(ya)（不包括CCFL共電(dian)(dian)）。一(yi)路供(gong)升壓(ya)(ya)電(dian)(dian)路；一(yi)路供(gong)N112（PU5100）脈寬(kuan)調制集(ji)成(cheng)電(dian)(dian)路。

N112的③腳加上5V電(dian)壓(ya)(ya)，經內(nei)部穩壓(ya)(ya)，恒流(liu)得到1.25V的基準電(dian)壓(ya)(ya)，由(you)⑨腳輸出(chu)。12腳外掛(gua)C174為定(ding)時電(dian)容。R151為定(ding)時電(dian)阻，其(qi)值決定(ding)N112的工作頻率，①、11腳輸入的正(zheng)負反饋(kui)電(dian)壓(ya)(ya)，經N112內(nei)部誤差放大(da)、PWM比較等，由(you)④腳輸出(chu)受控脈沖信號，經R143控制VD122（BR）開(kai)關管。

當(dang)(dang)VD122導(dao)(dao)通(tong)時(shi)，對L137蓄(xu)積電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。而VD122截止時(shi)，L137電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)經(jing)V123二(er)極(ji)(ji)(ji)管(guan)（MI）對C182充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負(fu)(fu)載能量(liang)，周(zhou)而復(fu)始(shi)。V1電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值為(wei)-14V，調(diao)節N112①腳(jiao)外接(jie)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R140阻(zu)(zu)值可改(gai)變(bian)其輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值；⑩腳(jiao)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，與來自15腳(jiao)的(de)(de)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)經(jing)N112內部(bu)誤(wu)差放(fang)大，PWM比(bi)較等(deng)(deng)，經(jing)⑤腳(jiao)輸出(chu)一(yi)個受(shou)控(kong)的(de)(de)脈(mo)沖(chong)信(xin)號，經(jing)R146控(kong)制VD127（IR）開關(guan)管(guan)，當(dang)(dang)VD127導(dao)(dao)通(tong)時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流從(cong)L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)集(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)到(dao)(dao)發射(she)極(ji)(ji)(ji)形成(cheng)回路(lu)，從(cong)而在L13l中蓄(xu)積能量(liang)。而VD127截止時(shi)，L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中的(de)(de)能量(liang)經(jing)VD128（MI）對C181電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負(fu)(fu)載能量(liang)周(zhou)而復(fu)始(shi)工作(zuo)(zuo)。V2電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值為(wei)13.6V，調(diao)節R144阻(zu)(zu)值可改(gai)變(bian)其輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值；由⑩腳(jiao)輸入的(de)(de)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，與來自14腳(jiao)的(de)(de)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)經(jing)N112內部(bu)誤(wu)差放(fang)大，PWM比(bi)較等(deng)(deng)。經(jing)⑥腳(jiao)輸出(chu)一(yi)個受(shou)控(kong)的(de)(de)脈(mo)沖(chong)信(xin)號，經(jing)R145控(kong)制VD125（IR）開關(guan)管(guan)，當(dang)(dang)VD125導(dao)(dao)通(tong)時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流從(cong)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)集(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)到(dao)(dao)發射(she)極(ji)(ji)(ji)形成(cheng)回路(lu)，從(cong)而在L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中蓄(xu)積能量(liang)，VD125截止時(shi)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中的(de)(de)能量(liang)經(jing)VD126二(er)極(ji)(ji)(ji)管(guan)（MI）對C124電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負(fu)(fu)載能量(liang)周(zhou)而復(fu)始(shi)工作(zuo)(zuo)。V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值為(wei)7.5V，調(diao)節14腳(jiao)外接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R152阻(zu)(zu)值，可改(gai)變(bian)其輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)值。V1、V2、V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)主要作(zuo)(zuo)為(wei)方波放(fang)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源。