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(dong)(dong)DVD機(ji)，受其(qi)體積限制(zhi)，外(wai)接電(dian)(dian)池電(dian)(dian)壓大多為9V左右，但(dan)其(qi)液晶(jing)屏(ping)驅(qu)動(dong)(dong)部分(fen)，需要(yao)多組不(bu)同(tong)的電(dian)(dian)壓，因此(ci)移動(dong)(dong)DVD機(ji)液晶(jing)屏(ping)驅(qu)動(dong)(dong)部分(fen)的供電(dian)(dian)電(dian)(dian)路相對較(jiao)(jiao)為復雜(za)，故障率也較(jiao)(jiao)高。附(fu)圖為新科SDP1710型移動(dong)(dong)DVD機(ji)液晶(jing)屏(ping)驅(qu)動(dong)(dong)部分(fen)電(dian)(dian)路圖。

此電(dian)(dian)路為液晶(jing)屏驅(qu)動(dong)供電(dian)(dian)電(dian)(dian)路（又(you)稱二次升壓(ya)電(dian)(dian)路）。因彩(cai)色(se)TFT顯示屏播放視頻(pin)圖(tu)像時(shi)，要(yao)求有快(kuai)速響應時(shi)間，對于(yu)控制(zhi)電(dian)(dian)路，意味著要(yao)加(jia)上更高的(de)驅(qu)動(dong)電(dian)(dian)壓(ya)；TFT屏的(de)非晶(jing)薄膜晶(jing)體管(guan)的(de)閾值電(dian)(dian)壓(ya)較高，輸入(ru)的(de)信(xin)號有的(de)高達20V。而此電(dian)(dian)壓(ya)作為便(bian)捷式(shi)產品，一般難(nan)以達到要(yao)求，故(gu)需要(yao)通過升壓(ya)電(dian)(dian)路來變換(huan)。

由N106五(wu)端5V穩壓(ya)集(ji)成電路(lu)③腳輸出5V電壓(ya)，此電壓(ya)作為(wei)整(zheng)個液晶屏驅動(dong)的輸入電壓(ya)（不包括CCFL共(gong)電）。一路(lu)供(gong)升壓(ya)電路(lu)；一路(lu)供(gong)N112（PU5100）脈寬調制集(ji)成電路(lu)。

N112的③腳(jiao)加上(shang)5V電(dian)壓(ya)，經(jing)內部穩壓(ya)，恒(heng)流得(de)到(dao)1.25V的基準電(dian)壓(ya)，由(you)⑨腳(jiao)輸出。12腳(jiao)外掛C174為定時電(dian)容。R151為定時電(dian)阻，其值決定N112的工作頻率，①、11腳(jiao)輸入的正負反饋電(dian)壓(ya)，經(jing)N112內部誤差放大、PWM比較等，由(you)④腳(jiao)輸出受控脈沖(chong)信號，經(jing)R143控制(zhi)VD122（BR）開關管。

當VD122導(dao)通時，對(dui)L137蓄積電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。而(er)VD122截(jie)止時，L137電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)經(jing)V123二(er)極(ji)管（MI）對(dui)C182充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負載能(neng)量(liang)，周而(er)復始(shi)。V1電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)為-14V，調(diao)(diao)節N112①腳(jiao)外接反饋電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R140阻(zu)值(zhi)(zhi)可(ke)改(gai)變(bian)其(qi)(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)；⑩腳(jiao)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，與來自15腳(jiao)的(de)(de)(de)反饋電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經(jing)N112內(nei)部誤差放大，PWM比較(jiao)等(deng)，經(jing)⑤腳(jiao)輸(shu)出一(yi)個(ge)受控(kong)(kong)(kong)的(de)(de)(de)脈(mo)沖信號(hao)，經(jing)R146控(kong)(kong)(kong)制VD127（IR）開關(guan)管，當VD127導(dao)通時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)從(cong)(cong)(cong)L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)到(dao)發射極(ji)形(xing)成回路(lu)，從(cong)(cong)(cong)而(er)在(zai)L13l中(zhong)蓄積能(neng)量(liang)。而(er)VD127截(jie)止時，L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)的(de)(de)(de)能(neng)量(liang)經(jing)VD128（MI）對(dui)C181電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負載能(neng)量(liang)周而(er)復始(shi)工作(zuo)。V2電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)為13.6V，調(diao)(diao)節R144阻(zu)值(zhi)(zhi)可(ke)改(gai)變(bian)其(qi)(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)；由⑩腳(jiao)輸(shu)入的(de)(de)(de)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，與來自14腳(jiao)的(de)(de)(de)反饋電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經(jing)N112內(nei)部誤差放大，PWM比較(jiao)等(deng)。經(jing)⑥腳(jiao)輸(shu)出一(yi)個(ge)受控(kong)(kong)(kong)的(de)(de)(de)脈(mo)沖信號(hao)，經(jing)R145控(kong)(kong)(kong)制VD125（IR）開關(guan)管，當VD125導(dao)通時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)從(cong)(cong)(cong)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)到(dao)發射極(ji)形(xing)成回路(lu)，從(cong)(cong)(cong)而(er)在(zai)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)蓄積能(neng)量(liang)，VD125截(jie)止時L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)的(de)(de)(de)能(neng)量(liang)經(jing)VD126二(er)極(ji)管（MI）對(dui)C124電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供(gong)負載能(neng)量(liang)周而(er)復始(shi)工作(zuo)。V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)為7.5V，調(diao)(diao)節14腳(jiao)外接電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R152阻(zu)值(zhi)(zhi)，可(ke)改(gai)變(bian)其(qi)(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)。V1、V2、V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)主要作(zuo)為方波放大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源。