镜象电流源 T1,T2完全对称 B=B,=B BE2 ln=,+2 R %IR=IREF 21B +2 C 2 B (1+ B C2 R R 基本镜象电流源输出电阻rn=ra镜象电流源 BE1 BE2 BE 1 2 V =V =V b = b = b I I I I I I R C B C B C ( ) = + = + = + 1 2 2 2 2 1 2 b 2 CC BE R o ce r r R V V I = − = 基本镜象电流源 输出电阻 T1,T2完全对称 Io=IC2 ≈IR