三极管在开关状态时的电流方向 三极管放大状态时的电流方向
\u8ba9\u4e09\u6781\u7ba1\u5b8c\u5168\u5904\u4e8e\u5f00\u5173\u72b6\u6001\u7684\u7535\u6d41\u8be5\u5982\u4f55\u770b\u5462?\u53c2\u6570\u540d\u5b57\u53eb\u4ec0\u4e48\u5462\u7ed3\u679c\u6b63\u786e\uff0c\u4f46\u8fc7\u7a0b\u6709\u4e9b\u5c0f\u95ee\u9898\u3002
(1) Q5\u7684Ib\u7535\u6d41\u662f\uff08\uff084.2V-0.7V\uff09/1K/2=1.75mA \u2014\u2014\u9519\u8bef
\u5e94\u8be5\uff1aQ5\u7684Ib\u7535\u6d41\u662f(4.2V-0.7V)/1K-0.7V/10K=3.5mA-0.07mA=3.43mA
\u4f46\u8fd9\u91cc\u4e0d\u9700\u8981\u8ba1\u7b97Q5\u7684Ib\u7535\u6d41\u3002\u6240\u4ee5\u9519\u8bef\u4e0d\u5f71\u54cd\u7ed3\u679c\u3002
(2) Q4\u7684Ic\u7535\u6d41\u662f \uff084.2V-0.7V\uff09/1K=3.5mA \u2014\u2014\u6b63\u786e
\u4e25\u683c\u6765\u8bf4\uff0c\u5e94\u8be5\u662fQ4\u9971\u548c\u65f6\u7684Ic\u7535\u6d41
(3) \u8ba9Q4\u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\u7684\u8d77\u59cb\u57fa\u6781\u7535\u6d41\u662f3.5mA/20=0.175mA
\u5e94\u8be5\u662f\uff1a\u8ba9Q4\u5de5\u4f5c\u5728\u9971\u548c\u72b6\u6001\u7684\u6700\u5c0f\u57fa\u6781\u7535\u6d41\u662f3.5mA/20=0.175mA
(4) \u90a3\u4e48R12\u7684\u53d6\u503c\u5e94\u8be5\u662f \uff083.3V-0.7V\uff09/0.175=14857\u6b27\u59c6 \u7ea6\u7b49\u4e8e15K\uff0c\u90a3\u4e48\u5c0f\u4e8e15K\u5c31\u53ef\u4ee5\u8ba9Q4\u5de5\u4f5c\u5728\u9971\u548c\u72b6\u6001\u4e0b\u3002
\u5e94\u8be5\u8bf4\u662f\uff1aR12\u7684\u6700\u5927\u503c\u5e94\u8be5\u662f\u2026\u2026
==========================================================================
\u5206\u6790\uff1a\u8981\u4f7f\u4e09\u6781\u7ba1\u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\uff0c\u5173\u952e\u662f\u8981\u8ba9Q4\u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\uff0c\u53ea\u8981Q4 \u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\uff0cQ5\u4e5f\u5c31\u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\u4e86\u3002
Q4 \u5de5\u4f5c\u5728\u5f00\u5173\u72b6\u6001\uff1a
PIN6=0V\u65f6Q4\u622a\u6b62\uff08\u4e0d\u9700\u8981\u8ba1\u7b97\uff09
PIN6=3.3V\u65f6Q4\u9971\u548c\uff08\u8fd9\u662f\u5173\u952e\uff09
Q4\u9971\u548c\u65f6\uff1aVc\u22480V\uff0c\u56e0\u6b64\u6709\u5e94\u8be5\u662fQ4\u9971\u548c\u65f6\u7684Ic\u7535\u6d41\uff084.2V-0.7V\uff09/1K=3.5mA
\u8fd9\u91ccR13\u4e0d\u53c2\u4e0e\u8ba1\u7b97\uff0c\u6709\u4e0e\u6ca1\u6709\u4e0d\u5f71\u54cd\u7ed3\u679c\u3002\u800cR13\u7684\u4f5c\u7528\u662f\u5728Q4\u622a\u6b62\u65f6\u4fdd\u8bc1Q5\u7684\u53ef\u9760\u622a\u6b62\uff0c\u56e0\u4e3a\u867d\u7136Q4\u622a\u6b62\uff0c\u4f46Q4\u6709\u4e00\u5b9a\u7684\u622a\u6b62\u6f0f\u7535\u6d41\uff0c\u800c\u8fd9\u4e2a\u6f0f\u7535\u6d41\u4f1a\u901a\u8fc7Q5\u8fdb\u884c\u653e\u5927\uff0cR13\u5c31\u662f\u628a\u8fd9\u4e2a\u6f0f\u7535\u6d41\u91ca\u653e\u6389\uff0c\u53ea\u8981\u8fd9\u4e2a\u6f0f\u7535\u6d41\u5728R13\u4e0a\u7684\u538b\u964d\u4e0d\u8d85\u8fc70.5V\uff0c\u5c31\u80fd\u4fdd\u8bc1Q5\u7684\u53ef\u9760\u622a\u6b62\u3002
\u5176\u5b9e\u8fd9\u4e2a\u7535\u8def\uff0c\u4e09\u6781\u7ba1\u5bfc\u901a\u53ea\u662f\u4e3a\u4e86\u7ed9\u7535\u5bb9\u4e00\u4e2a\u653e\u7535\u56de\u8def\uff0c\u4e09\u6781\u7ba1\u4e0d\u5bfc\u901a\u65f6\uff0c\u7535\u6d41\u901a\u8fc7\u626c\u58f0\u5668\u5230\u7535\u5bb9\uff0c\u6b64\u65f6\u7535\u5bb9\u5145\u7535\uff0c\u6d41\u8fc7\u626c\u58f0\u5668\u7684\u7535\u6d41\u4e0d\u65ad\u51cf\u5c0f\u3002
\u4e09\u6781\u7ba1\u5bfc\u901a\uff0c\u7535\u5bb9\u88ab\u653e\u7535\u6b64\u65f6\u6d41\u8fc7\u626c\u58f0\u5668\u7684\u7535\u6d41\u53c8\u589e\u5927\u3002
\u56e0\u6b64\u626c\u58f0\u5668\u5728\u6b63\u534a\u5468\u671f\u53ef\u4ee5\u83b7\u5f97\u4e00\u4e2a\u65b9\u5411\u4e0d\u53d8\uff0c\u5927\u5c0f\u4e00\u76f4\u5728\u6539\u53d8\u7684\u4ea4\u6d41\u4fe1\u53f7\u3002
三极管截止，输出高电平，集电极电流为0，输出电流通过Rc输出，此电流对外称为拉电流。
三极管导通，输出低电平，集电极电压为0.3V，电流通过集电极流向发射极，此电流对外称为灌电流。
绛旓細涓夋瀬绠瀵奸氾紝杈撳嚭浣庣數骞筹紝闆嗙數鏋佺數鍘嬩负0.3V锛鐢垫祦閫氳繃闆嗙數鏋佹祦鍚戝彂灏勬瀬锛屾鐢垫祦瀵瑰绉颁负鐏岀數娴併
绛旓細瀵逛簬鏅朵綋绠涓夋瀬绠鏉ヨ锛氬湪鏀惧ぇ鐢佃矾涓紝闆嗙數鏋佷笉鍙綔涓轰俊鍙风殑杈撳叆绔紝鍩烘瀬涓嶅彲浣滀负淇″彿鐨勮緭鍏ョ銆傚浜嶯PN鍨嬫櫠浣撶鏉ヨ锛鐢垫祦浠庨泦鐢甸泦C鍜屽熀鏋丅娴佸悜鍙戝皠鏋丒锛涘浜嶱NP鏅朵綋绠℃潵璇达細鐢垫祦浠庡彂灏勬瀬E娴佸悜鍩烘瀬B鍜岄泦鐢垫瀬C銆
绛旓細瀵逛簬NPN绠★紝NPN涓夋瀬绠瑕佸閫氬垯闇瑕佷袱涓狿N缁澶勪簬姝ｅ亸鐢靛帇锛孨PN鏄敤B鈥擡鐨勭數娴锛圛B锛夋帶鍒禖鈥擡鐨勭數娴侊紙IC锛夛紝E鏋佺數浣嶆渶浣庯紝涓旀甯告斁澶ф椂閫氬父C鏋佺數浣嶆渶楂橈紝鍗砎C>VB>VE銆傛墍浠ワ紝鐢垫祦鐨勬祦鍚戞槸鐢盋鏋佹祦鍚慐鏋併侭鏋佹槸鎺у埗鑴氾紝B鐨勭數娴佹祦鍚慐銆傚浜嶱NP绠★紝PNP鏄敤E鈥擝鐨勭數娴侊紙IB锛夋帶鍒禘鈥擟鐨勭數娴侊紙IC锛夛紝...
绛旓細涓夋瀬绠＄殑鐢垫祦鏄粠闆嗙數鏋佹祦鍏ワ紝鍙戝皠鏋佹祦鍑銆備笁鏋佺瑕佹斁澶э紝鏈変袱涓潯浠讹細鍙戝皠缁撴鍋忥紝闆嗙數缁撳弽鍋忋傚浜嶯PN绠℃潵璇达紝鍙戝皠缁撴槸鍩烘瀬锛圥锛夋寚鍚戝彂灏勬瀬锛圢锛夛紝闆嗙數缁撴槸鍩烘瀬锛圥锛夋寚鍚戦泦鐢垫瀬锛圢锛夈傝屼笖瀵逛簬鍗婂浣撴潵璇达紝澶氬瓙鏄惡甯︾數鑽风殑涓绘祦锛屼唬琛ㄤ富瑕佺數娴佺殑鏂瑰悜銆傚厛鐪嬪彂灏勬瀬锛岀敱浜庢槸N鍖猴紝澶氬瓙鏄數瀛愶紙璐熺數锛夈...
绛旓細1銆佹埅姝㈢姸鎬 褰撳姞鍦ㄤ笁鏋佺鍙戝皠缁撶殑鐢靛帇灏忎簬PN缁撶殑瀵奸氱數鍘嬶紝鍩烘瀬鐢垫祦涓洪浂锛岄泦鐢垫瀬鐢垫祦鍜屽彂灏勬瀬鐢垫祦閮戒负闆讹紝涓夋瀬绠¤繖鏃跺け鍘讳簡鐢垫祦鏀惧ぇ浣滅敤锛岄泦鐢垫瀬鍜屽彂灏勬瀬涔嬮棿鐩稿綋浜庡紑鍏崇殑鏂紑鐘舵侊紝鍗充负涓夋瀬绠＄殑鎴鐘舵併傚紑鍏涓夋瀬绠″浜鎴鐘舵佺殑鐗瑰緛鏄彂灏勭粨锛岄泦鐢电粨鍧囧浜庡弽鍚戝亸缃2銆佸閫氱姸鎬 褰撳姞鍦ㄤ笁鏋佺鍙戝皠缁撶殑鐢靛帇...
绛旓細鏄惁鏄紑鍏充綔鐢紝鍙鐪涓夋瀬绠鏄笉鏄伐浣滃湪瀵奸氭埅姝㈢姸鎬侊紝濡傛灉鏄紝鍒欎笁鏋佺宸ヤ綔鍦ㄥ紑鍏崇姸鎬锛屾湰渚嬫槸鍦ㄦ斁澶х姸鎬併傝繖涓弽棣堢數璺富瑕佹槸鍒ゆ柇鍙嶉鐨勬ц川锛屽浣犳墍绀篟e1鐢垫祦鏂瑰悜锛岀數闃讳笂姝ｃ佷笅璐燂紝鎴戜滑鐭ラ亾锛歍1闆嗙數鏋佷负璐燂紝T2闆嗙數鏋佷负姝ｏ紝鎵浠ワ紝鐢垫祦閫氳繃Rf銆丷e1鍒板湴锛孯e1涓篢1鐨勪覆鑱旂數鍘嬭礋鍙嶉锛孯f澧炲ぇ浜哛e1鐨勫帇闄...
绛旓細鍗婂浣涓夋瀬绠鏈変笁绉嶅伐浣鐘舵锛氭斁澶с佹埅姝㈠拰楗卞拰銆備笁绉嶅伐浣滅姸鎬佸湪寮鍏夌姸鎬佸搴旂殑鏉′欢涓嶅悓銆傚綋鍙戝皠鏋佸拰闆嗙數鏋佺殑鐢靛帇瓒呰繃涓瀹氭暟鍊煎悗锛孖c=尾Ib锛屾櫠浣撶鍏锋湁鐢垫祦鏀惧ぇ浣滅敤锛澶勪簬鏀惧ぇ鍖猴紝鍙戝皠鏋佸浜庢鍚戝亸缃紝闆嗙數鏋佸浜庡弽鍚戝亸缃傚綋Ib=0鏃讹紝Ic=0銆傚NPN鍨嬬绠★紝褰撳彂灏勬瀬鐢靛帇Ube 0.5V鏃讹紝绠″瓙宸茬粡寮濮嬫埅姝紝浣...
绛旓細鎴鐘舵 褰撳姞鍦ㄤ笁鏋佺鍙戝皠缁撶殑鐢靛帇灏忎簬PN缁撶殑瀵奸氱數鍘嬶紝鍩烘瀬鐢垫祦涓洪浂锛岄泦鐢垫瀬鐢垫祦鍜屽彂灏勬瀬鐢垫祦閮戒负闆讹紝涓夋瀬绠¤繖鏃跺け鍘讳簡鐢垫祦鏀惧ぇ浣滅敤锛岄泦鐢垫瀬鍜屽彂灏勬瀬涔嬮棿鐩稿綋浜庡紑鍏崇殑鏂紑鐘舵侊紝鍗充负涓夋瀬绠＄殑鎴鐘舵併傚紑鍏涓夋瀬绠″浜鎴鐘舵佺殑鐗瑰緛鏄彂灏勭粨锛岄泦鐢电粨鍧囧浜庡弽鍚戝亸缃傚閫氱姸鎬 褰撳姞鍦ㄤ笁鏋佺鍙戝皠缁撶殑鐢靛帇澶т簬PN缁...
绛旓細闆嗙數缁撳弽鍋忥細涓夋瀬绠″湪姝ｅ父宸ヤ綔鐘舵佹椂锛屽姞鍦ㄩ泦鐢垫瀬涓婄殑鐢靛帇鏂瑰悜涓庡叾鐢垫祦鏂瑰悜鐩稿弽銆傚湪鏀惧ぇ鐢佃矾涓璪e缁撴鍋忥紝bc缁撳弽鍋忥紝涓夋瀬绠″伐浣滃湪鏀惧ぇ鍖猴紝鍦ㄦ暟瀛楃數璺腑bc缁0鍋忔垨鍙嶅亸锛屼笁鏋佺浜ゆ浛宸ヤ綔鍦ㄩケ鍜屽尯鍜屾埅姝㈠尯銆傛鍋忥細褰撳鐣屾湁姝ｅ悜鐢靛帇鍋忕疆鏃讹紝澶栫晫鐢靛満鍜岃嚜寤虹數鍦虹殑浜掔浉鎶戞秷浣滅敤浣胯浇娴佸瓙鐨勬墿鏁ｇ數娴佸鍔犲紩璧蜂簡姝ｅ悜...
绛旓細褰撳姞鍦ㄤ笁鏋佺鍙戝皠缁撶殑鐢靛帇灏忎簬PN缁撶殑瀵奸氱數鍘嬫椂锛涓夋瀬绠″浜鎴鐘舵銆傛鏃讹紝鍩烘瀬鐢垫祦涓洪浂锛岄泦鐢垫瀬鍜屽彂灏勬瀬鐨勭數娴涔熼兘涓洪浂锛屼笁鏋佺澶卞幓浜嗗叾鐢垫祦鏀惧ぇ鍔熻兘銆傞泦鐢垫瀬鍜屽彂灏勬瀬涔嬮棿鐨勭數鍔垮樊鐩稿綋浜庡紑鍏鏂紑锛岃〃鏄庝簡杩欑鐘舵佺殑鐗圭偣鏄彂灏勭粨鍜岄泦鐢电粨閮藉浜庡弽鍚戝亸缃傚彟涓鏂归潰锛屽綋鍙戝皠缁撶殑鐢靛帇瓒呰繃瀵奸氱數鍘嬶紝骞朵笖鍩烘瀬鐢垫祦...
