PURPOSE: To obtain an amplitude equalizer with less number of components and also less DC offset generated from the circuit by providing an operational amplifier whose non-inverting input terminal is connected to a common potential point or the like.
CONSTITUTION: The operational amplifier M whose non-inverting input terminal is connected to a common potential point, the 1st∼5th capacitors K1∼K5 and the 1st switching means SW1 switching the signal input terminal 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+K=(2+K1-K2K4)Z-1+Z-2, Z=ejωt C1=C2=1.0, K2=K3 and T= 1/fc (fc: clock frequency). The DC offset of this circuit is decreased by increasing the K4.
IZAWA YUUHEI
KAWAKAMI IZUMI
