SUMMARYThis paper presents an integrated approach of simulated annealing (SA) and genetic algorithm (GA) for the analogue module placement in mixed-signal integrated circuit layout designs. The proposed algorithm follows the optimization ow of a normal GA controlled by the methodology of SA. The bitmatrix chromosomal representation is employed to describe the location and the orientation of modules. Compared with the conventional bit-string representation, the proposed chromosomal representation tends to signiÿcantly improve the search e ciency. In addition, a slide-based at scheme is developed to transform an absolute co-ordinate placement of modules to a relative placement. In this way, the symmetry constraints imposed on analogue very large scale integration circuits can be easily fulÿlled in the placement run. Use of a radiation-decoder can also drastically shrink the conÿguration space without degrading search opportunities. The proposed algorithm has been tested with several example circuits. The experiments show this promising algorithm makes the better performance than the simpler SA or GA approaches working alone, and the quality of the automatically generated layouts is comparable to those done manually.

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SUMMARYBesides 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 appfication 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.

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