二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)主要(yao)(yao)特(te)(te)性(xing)就(jiu)是(shi)單向(xiang)(xiang)導電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。可用(yong)(yong)(yong)于(yu)：檢波(bo)、整(zheng)流(liu)、穩(wen)壓(ya)(ya)、隔離反(fan)(fan)向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)；另有(you)發(fa)光(guang)(guang)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、阻尼二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、光(guang)(guang)敏(min)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、壓(ya)(ya)敏(min)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、氣敏(min)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)等(deng)等(deng)專(zhuan)用(yong)(yong)(yong)半導體器件。 1、作用(yong)(yong)(yong)：二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)主要(yao)(yao)特(te)(te)性(xing)是(shi)單向(xiang)(xiang)導電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)性(xing)，也就(jiu)是(shi)在(zai)正向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)作用(yong)(yong)(yong)下，導通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻很小；而(er)(er)在(zai)反(fan)(fan)向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)作用(yong)(yong)(yong)下導通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)大(da)或(huo)無窮(qiong)大(da)。正因為二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)具有(you)上述特(te)(te)性(xing)，無繩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)話機(ji)中(zhong)(zhong)常把(ba)它用(yong)(yong)(yong)在(zai)整(zheng)流(liu)、隔離、穩(wen)壓(ya)(ya)、極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)性(xing)保護、編碼(ma)控制、調(diao)(diao)頻(pin)調(diao)(diao)制和靜噪等(deng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)中(zhong)(zhong)。晶體二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)按作用(yong)(yong)(yong)可分為：整(zheng)流(liu)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如(ru)1N4004）、隔離二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如(ru)1N4148）、肖(xiao)特(te)(te)基(ji)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（如(ru)BAT85）、發(fa)光(guang)(guang)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、穩(wen)壓(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)等(deng) 2、穩(wen)壓(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)壓(ya)(ya)原理(li)：穩(wen)壓(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)特(te)(te)點(dian)就(jiu)是(shi)擊穿后，其兩端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)基(ji)本保持不變(bian)(bian)。這(zhe)樣(yang)，當把(ba)穩(wen)壓(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)接入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)以后，若(ruo)由于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)發(fa)生波(bo)動，或(huo)其它原因造成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)中(zhong)(zhong)各點(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)變(bian)(bian)動時，負載兩端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)將基(ji)本保持不變(bian)(bian) 3.變(bian)(bian)容(rong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)根據普(pu)通(tong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)內部 “PN結” 的(de)(de)(de)(de)結電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)能隨外(wai)加反(fan)(fan)向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)變(bian)(bian)化而(er)(er)變(bian)(bian)化這(zhe)一原理(li)專(zhuan)門設計(ji)出來的(de)(de)(de)(de)一種(zhong)特(te)(te)殊二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)。 變(bian)(bian)容(rong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)在(zai)無繩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)話機(ji)中(zhong)(zhong)主要(yao)(yao)用(yong)(yong)(yong)在(zai)手機(ji)或(huo)座機(ji)的(de)(de)(de)(de)高(gao)頻(pin)調(diao)(diao)制電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)上，實(shi)(shi)現(xian)低頻(pin)信號調(diao)(diao)制到高(gao)頻(pin)信號上，并發(fa)射(she)出去(qu)。在(zai)工作狀態，變(bian)(bian)容(rong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)調(diao)(diao)制電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)一般加到負極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)上，使變(bian)(bian)容(rong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)內部結電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)容(rong)量隨調(diao)(diao)制電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)變(bian)(bian)化而(er)(er)變(bian)(bian)化 4.光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（LED） 光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)、光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)三極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)中(zhong)(zhong)廣泛采用(yong)(yong)(yong)的(de)(de)(de)(de)光(guang)(guang)敏(min)器件。光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和普(pu)通(tong)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)一樣(yang)具有(you)一個(ge)PN結，不同(tong)之處(chu)是(shi)在(zai)光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)二(er)(er)(er)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)外(wai)殼上有(you)一個(ge)透(tou)明的(de)(de)(de)(de)窗口以接收(shou)光(guang)(guang)線照射(she)，實(shi)(shi)現(xian)光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)換，在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)圖中(zhong)(zhong)文字符號一般為VD。光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)三極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)除具有(you)光(guang)(guang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)換的(de)(de)(de)(de)功(gong)能外(wai)，還具有(you)放大(da)功(gong)能，在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)圖中(zhong)(zhong)文字符號一般為VT。