Design of wave‐sc filters using building blocks

Besides switched‐capacitor (SC) filters developed for high volume production, e.g. the PCM‐codec lowpass filter, numerous low volume applications exist in the area of solid‐state filtering. to open up this application field for SC filters, a novel wave‐SC filter structure is presented. the filter design using this concept requires only moderate design and layout skills since only a limited library of highly modular building blocks is required. It is also suitable for analogue gate array applications. As will be shown, the wave equations which are known from the theory of wave digital filters can be realized using stray‐insensitive SC integrators and SC amplifiers only. Exemplary designs of a lowpass, a highpass, and a bandpass filter will be carried out with the building blocks presented. the theoretical results are verified by measurements at the breadboarded lowpass filter.