Rc RL R B1△ t lod Ro RL R R TIE T2 u D r R Id 2△ 2 EE b2 差模放大倍数A △L R Od B(R。) △ Id Rb+r △i·2(R2∥ R R=2(Rb +rbe) R=2R O) 2 2( 2( ) L Od C c Id B b be Id Od d R u i R u i R r u u A ∥ 差模放大倍数  = −   =   +   = 2 2( ) ) 2 ( o c i b be b be L c d R R R R r R r R R A = = + + = −  ∥