Low-sensitivity current-mode active-RC filters using impedance tapering

This paper is concerned with a new design method of low-sensitivity current-mode filters, which results from low-sensitivity voltage-mode filter design using impedance tapering. The current-mode filters are obtained by application of a network transposition to their voltage-mode counterparts, in which the passive-RC network remains the same, and both filters are expected to have identical sensitivity properties. However, current-mode filters may be easier to realize in IC form and are expected to have higher bandwidths, greater linearity and wider dynamic range than the voltage-mode filters. In this paper, the 2nd-order class-4 current-mode filters (with positive feedback) are considered. Design procedures are given for the design of low-sensitivity low-pass (LP), high-pass (HP), band-pass (BP) and band-rejection (BR)) filters, which are all realizable in class-4. A sensitivity analysis is examined using PSpice Monte Carlo runs.