VLSI implementation of the metering signal generator for switching system analog terminations

Abstract

Describes a mixed analog-digital integrated circuit to be employed in a Central Exchange Switching System. This generates a proper shaped telephone metering pulse, according to the actual international standards, and sends it to eight subscribers. It has been designed with a cell-based approach and implemented with a 3 mu m double poly single metal CMOS technology. 80% of the circuit uses digital and analog cells, while 20% has been specifically designed down to a transistor level. In order to reduce the power consumption two different supplies was used.<>