Selective linear phase switched-capacitor filters modelled on classical structures

Abstract

Exact analytic techniques are given for the design of straysinsensitive lossless discrete integrator (LDI) switched-capacitor low-pass and high-pass filters, with phase linearity taken into consideration. An improved synthesis algorithm is also presented for the low-pass case. The given solutions appear for the first time in relation to switched-capacitor filters, but they rely on classical techniques in the area of passive (distributed) networks and cannot be obtained from lumped-element filters. Due to the importance of the topic and the paucity of useful results, parts of the paper are written in a review-like semi-tutorial style, in order to make the design techniques accessible to as wide a readership as possible. This paper, together with [2] and [4], constitute a comprehensive procedure for the exact design of LDI low-pass and high-pass filters with or without phase linearity; thus completing the picture for these important classes of switched-capacitor filters.