二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)主(zhu)要(yao)特(te)(te)性就(jiu)(jiu)是(shi)單(dan)向(xiang)導(dao)(dao)電(dian)(dian)(dian)(dian)。可用(yong)(yong)(yong)(yong)于(yu)：檢波、整流、穩壓(ya)(ya)(ya)(ya)、隔離反向(xiang)電(dian)(dian)(dian)(dian)；另(ling)有(you)發光(guang)(guang)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、阻尼二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、光(guang)(guang)敏二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、壓(ya)(ya)(ya)(ya)敏二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、氣(qi)敏二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)等(deng)等(deng)專(zhuan)用(yong)(yong)(yong)(yong)半導(dao)(dao)體器件(jian)。 1、作(zuo)用(yong)(yong)(yong)(yong)：二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)主(zhu)要(yao)特(te)(te)性是(shi)單(dan)向(xiang)導(dao)(dao)電(dian)(dian)(dian)(dian)性，也就(jiu)(jiu)是(shi)在(zai)正(zheng)(zheng)向(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)作(zuo)用(yong)(yong)(yong)(yong)下(xia)，導(dao)(dao)通(tong)電(dian)(dian)(dian)(dian)阻很小；而在(zai)反向(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)作(zuo)用(yong)(yong)(yong)(yong)下(xia)導(dao)(dao)通(tong)電(dian)(dian)(dian)(dian)阻極(ji)大(da)或(huo)無窮大(da)。正(zheng)(zheng)因(yin)為(wei)(wei)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)具(ju)有(you)上(shang)(shang)述特(te)(te)性，無繩電(dian)(dian)(dian)(dian)話(hua)機中(zhong)常把它(ta)用(yong)(yong)(yong)(yong)在(zai)整流、隔離、穩壓(ya)(ya)(ya)(ya)、極(ji)性保護、編(bian)碼(ma)控制(zhi)、調(diao)頻(pin)調(diao)制(zhi)和(he)靜噪等(deng)電(dian)(dian)(dian)(dian)路中(zhong)。晶體二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)按(an)作(zuo)用(yong)(yong)(yong)(yong)可分為(wei)(wei)：整流二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如1N4004）、隔離二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如1N4148）、肖(xiao)特(te)(te)基二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如BAT85）、發光(guang)(guang)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、穩壓(ya)(ya)(ya)(ya)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)等(deng) 2、穩壓(ya)(ya)(ya)(ya)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)穩壓(ya)(ya)(ya)(ya)原(yuan)理：穩壓(ya)(ya)(ya)(ya)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)特(te)(te)點就(jiu)(jiu)是(shi)擊穿后(hou)，其兩端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)基本(ben)保持(chi)不變(bian)(bian)。這樣，當把穩壓(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)接入電(dian)(dian)(dian)(dian)路以后(hou)，若由于(yu)電(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)發生波動(dong)，或(huo)其它(ta)原(yuan)因(yin)造成(cheng)電(dian)(dian)(dian)(dian)路中(zhong)各點電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)變(bian)(bian)動(dong)時，負載兩端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)將基本(ben)保持(chi)不變(bian)(bian) 3.變(bian)(bian)容(rong)(rong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)根據普(pu)通(tong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)內部(bu) “PN結” 的(de)(de)(de)(de)結電(dian)(dian)(dian)(dian)容(rong)(rong)能隨(sui)(sui)外(wai)加反向(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)變(bian)(bian)化而變(bian)(bian)化這一(yi)(yi)原(yuan)理專(zhuan)門設計出(chu)來的(de)(de)(de)(de)一(yi)(yi)種特(te)(te)殊二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)。 變(bian)(bian)容(rong)(rong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)在(zai)無繩電(dian)(dian)(dian)(dian)話(hua)機中(zhong)主(zhu)要(yao)用(yong)(yong)(yong)(yong)在(zai)手機或(huo)座機的(de)(de)(de)(de)高頻(pin)調(diao)制(zhi)電(dian)(dian)(dian)(dian)路上(shang)(shang)，實現低頻(pin)信號調(diao)制(zhi)到高頻(pin)信號上(shang)(shang)，并發射出(chu)去(qu)。在(zai)工(gong)作(zuo)狀態(tai)，變(bian)(bian)容(rong)(rong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)調(diao)制(zhi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)一(yi)(yi)般加到負極(ji)上(shang)(shang)，使變(bian)(bian)容(rong)(rong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)內部(bu)結電(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量隨(sui)(sui)調(diao)制(zhi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)變(bian)(bian)化而變(bian)(bian)化 4.光(guang)(guang)電(dian)(dian)(dian)(dian)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（LED） 光(guang)(guang)電(dian)(dian)(dian)(dian)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、光(guang)(guang)電(dian)(dian)(dian)(dian)三極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)路中(zhong)廣(guang)泛采用(yong)(yong)(yong)(yong)的(de)(de)(de)(de)光(guang)(guang)敏器件(jian)。光(guang)(guang)電(dian)(dian)(dian)(dian)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和(he)普(pu)通(tong)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)一(yi)(yi)樣具(ju)有(you)一(yi)(yi)個(ge)PN結，不同之處是(shi)在(zai)光(guang)(guang)電(dian)(dian)(dian)(dian)二(er)(er)(er)(er)(er)(er)(er)(er)極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)外(wai)殼上(shang)(shang)有(you)一(yi)(yi)個(ge)透(tou)明的(de)(de)(de)(de)窗口以接收光(guang)(guang)線照射，實現光(guang)(guang)電(dian)(dian)(dian)(dian)轉換，在(zai)電(dian)(dian)(dian)(dian)路圖(tu)中(zhong)文字符號一(yi)(yi)般為(wei)(wei)VD。光(guang)(guang)電(dian)(dian)(dian)(dian)三極(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)除具(ju)有(you)光(guang)(guang)電(dian)(dian)(dian)(dian)轉換的(de)(de)(de)(de)功能外(wai)，還(huan)具(ju)有(you)放(fang)大(da)功能，在(zai)電(dian)(dian)(dian)(dian)路圖(tu)中(zhong)文字符號一(yi)(yi)般為(wei)(wei)VT。