利用戴维宁定理等效变换后求解Q点 + R cQ R BB RbI+ Rh2 T T Rb=Rb1∥Rb2 BQ ●U Rb Rb上静态电压 R 可忽略不计! BB Bo Rb+UbeR+ lEQRe=lBo Rb+UbeR+(l+b)boRe URO =UREO +(1+ BIRoR 若(+B)R>>R,则UR1+k2"C bIb b1 b2 CC b1 b2 b1 BB R R R V R R R V = ∥  + = BQ BEQ BQ e BB BQ b BEQ EQ e BQ b BEQ BQ e (1 ) (1 ) U U I R V I R U I R I R U I R   = + + = + + = + + + 利用戴维宁定理等效变换后求解Q点 Rb上静态电压 可忽略不计！ CC b1 b 2 b1 e b BQ (1 ) V R R R R R U  + 若 +  ＞＞ ，则 