| 摘要 |
PURPOSE:To obtain an amplitude equivalent device with less number of components and less DC offset by providing an operational amplifier whose non-inverting input terminal is common potential point or the like. CONSTITUTION:The operational amplifier M whose non-inverting input terminal is connected to a common potential point, 1st-5th capacitors K1-K5, and the 1st switching means SW1 switching signal input terminals and the common potential point and connecting them to the other end of the 1st capacitor K1 or the like are provided. A transfer function T2(Z<-1>) of the circuit in the Z region is expressed by equation, where N2=K6(1+K1)-(2K6+K1K6-K2K5)Z<-1>+ K6Z<-2>, D2 =1+K1-(2+K1-K2K4)Z<-1>+Z<-2>, Z=e<jomegat>, C1=C2=1.0, K2=K3 and T=1/fc (fc: clock frequency). The DC offset Vout(0) of the circuit is decreased by increasing the K4. |
