Synthesis of follow-the-leader feedback log-domain filters

Abstract

A systematic approach for the design of log-domain filters is presented. The filters' structures are based on the inverse-follow-the-leader-feedback (IFLF) topology, therefore, they possess low sensitivity. To illustrate the proposed approach, seventh-order linear phase lowpass filters with tunable cutoff frequencies range from 100 kHz to 60 MHz are designed and simulated. Simulations' results indicate that the filters provide a tunable bandwidth (f/sub -3dB/) that extends from 100 kHz to 200 MHz, equalization up to 16 dB and 14 dB, power dissipation of 7 mW and 12 mW for the single-ended and the balanced versions; respectively.