Integrated circuits of P.C.M. transmissions

Abstract

The development of P.C.M. transmissions went through three sorts of equipments. The first kind was: in the early seventies, the use of transistors (T.T.L.); the second kind was: towards 1975, 7 specialized LSI were used in the terminal equipments, while the repeaters went on using the catalogue components; it can reasonably be thought that the third kind of equipments, in the eighties will be equiped with special LSI circuits which will be described later.