3.Inverting Amplifier反相放大器 ◆Voltage gain-Av 虚短：ywVp0 R 虚断：ip=iw=0→i2 i=i2→(y-vw)/R=(ywvo)/R2→vo=-(R2/R1) 求得：A,=-(R2R)→vo与相位相反 ◆Input resistance-R; 虚短：ywyp=0→R=y/-R1 ◆Output resistance-R。=O EWB演示3. Inverting Amplifier 反相放大器 vi vo - + R2 R1 vN vP ◆Voltage gain-Av i1 iN iP i2 虚短: vN =vP =0 虚断: iP = iN =0  i1= i2 i1= i2  (vi -vN )/R1 = (vN -vO )/R2  vO =－(R2 /R1 ) vi 求得：Av =－(R2 /R1 )  vO与 vi 相位相反 ◆Input resistance - Ri 虚短: vN =vP =0  Ri =vi / ii =R1 ◆Output resistance—Ro =0 Ri Ro EWB演示