A new transformation and design technique for switched capacitor high pass ladder filters.

Abstract

A new technique for the design of switched capacitor high-pass ladder filters using the MLDD transformation is proposed. It is shown that by realizing the resistive source termination of the high-pass continuous ladder proto-type filter with a special delay free circuit, a much superior response is obtained. A new transformation named the modified bilinear transformation for the design of switched capacitor high-pass lader filters is also proposed. Using this transformation and the proposed design technique, it is shown that the magnitude response of the switched capacitor high-pass ladder filter approximates the response of the continuous high-pass ladder proto-type much better than the MLDD transformation. However, in some of the applications this is achieved at the cost of a higher order filter. Finally, an interactive package for the design of the switched capacitor high-pass Butterworth and Chebychev filters using the MLDD and the modified bilinear transformations is presented as a bonus.