A switched-capacitor delay circuit for compensating the influences of both finite GB product of operational amplifier and parasitic capacitance

摘要

In this paper, a compensation circuit for the degradation characteristic of a switched-capacitor filter (SCF) by the influences of both finite gain-bandwidth (GB) product of operational amplifier (op-amp) in high frequency area and parasitic capacitance is proposed. In high frequency area, the characteristic of SCF deteriorates with the influence of finite GB product of op-amps as main factor. The parasitic capacitance on the circuit components also degrades the frequency characteristic. Several compensated circuits for the parasitic capacitance have been proposed. However, these circuits become sensitive to the parasitic capacitance when the finite GB product of the op-amp is considered. Then, we propose a compensation circuit for the influences of both finite GB product of op-amp and parasitic capacitance, and prove the usefulness of the proposed circuit construction by experiment using the constructed circuit with discrete components.