Abstract :
The rapid evolution from the transistor to the LSI circuit revolutionized telecommunications systems. In particular, the low-cost IC´s triggered the transition from wired- to stored-program control and from analog to digital techniques by introducing standard IC´s as microprocessors, memories, etc. The availability of analog-digital interface circuits, for example codecs, filters, SLIC´s, and vocoders, has become very important. In addition to the technical revolution, the economical aspects must be considered. LSI circuits enter more and more into the vicious circle of greater complexity-fewer applications and thus higher costs. An escape from this circle is offered by programmable circuits such as microprocessors or new circuits with a regular architecture. Nevertheless, custom circuits will always be used in order to protect the system know-how. The blend of standard and custom circuits will be important for the success of a systems house. Since vertical integration activities will be unlikely, different concepts of cooperation between IC manufacturers and system house become more and more important.
