用微变等效电路法进行多级放大电路的动态分析 i2 b2 Bll R B21 1I012IB12B22 be2 输入级 2=RL输出级 R=R Rul=rBu//rbi// reel=r R=R R 2=raulrAzz /rbe?= rul Ro2=rc=r -阝2I2(Rc2/R1)-2(Rc2/R1) b2be2 be2 阝1Ib1(Rc1RB12∥/RB2∥/R1 阝1(Rc1/Ra2) R bel A U Am×A u2Ii1 β2Ib2 β1Ib1 三、用微变等效电路法进行多级放大电路的动态分析 RS + - U Ui1 S Ib1 Rbe1 RB11 RB21 RB12 RB22 Rbe2 Ib2 RL RC2 RC1 输入级 输出级 U Uo i2 Uo1 AU2= = = Uo Ui2 – β2Ib2 (RC2//RL) Ib2Rbe2 – β2 (RC2//RL) Rbe2 – β1Ib1 (RC1// RB12 // RB22 // Rbe2 ) AU1= = = Uo1 Ui1 Ib1Rbe1 – β1 (RC1//Ri2) Rbe1 Ri1 = RB11 // RB21 // Rbe1 = Ri Ro1 = RC1 Ri2 = RB12 // RB22 // Rbe2 = RL1 Ro2 = RC2 = Ro Ii2 AU = AU1 × AU2 Ri1=Ri Ro1 Ri2 =RL1 Ro2 = Ro