CANCELLATION TECHNIQUE OF PARASITICS IN ACTIVE-FILTER DESIGN

This letter presents a technique to cancel the parasitic effects of op erational amplifier (op amp) in active filter design. To minimize the effects, an op amp model considering the parasitics (i.e. both parasit ic poles and zeros) is utilized. It is shown that undesirable factors in the transfer function due to the parasitics can be canceled well by predistorting the passive element values of the circuit. As an exampl e, an active-R highpass filter is evaluated both theoretically and num erically. In this way, the proposed technique can be effectively incor porated into the design of active filters.