Microelectronics has revolutionized the architecture and design concep
ts of telecommunications products dramatically. Its strength is based
on the combination of three different disciplines : technology, design
automation and device architecture. The evolution in all these topics
will be described and illustrated with several examples of telecommun
ications applications. At present VLSI circuits are used in three impo
rtant business segments of the telecommunications market : switching,
transmission and end-user systems. The technology requirements for the
se applications are followed by a brief discussion on reliability requ
irements and future technology trends.