The inexorable increase in levels of integration of electronic circuits
has most often been exploited using digital signals. So much so that
design engineers have sought to digitise analogue signals as early as
possible in the signal processing chain, and performed digital
processing wherever practicable.
However it is increasingly being accepted that such an approach is not
appropriate for many applications, and that circuits which combine
analogue and digital signals can provide superior solutions. There are
at least three factors which support this trend. Firstly improved
process technology giving better dimensional and parametric control and
the availability of BiCMOS and CMOS processes able to support both
analogue and digital components. Secondly the maturing of discrete time
circuit techniques giving competitive high performance solutions.
Thirdly the gain in terms of reliability and reduction in cost achieved
by mixing analogue and digital signal processing and hence implementing
'systems' on a single substrate.
It is therefore timely that wide ranging books such as this one, on the
subject of mixed analogue digital ASICs should appear. It comprises
eighteen chapters contributed by leading academics and practising
engineers in industry. The chapters are arranged in four sections:
Processing technology; Circuit Techniques and Building Blocks; Design
and Applications; and CAD and Supporting Tools.