Circuit layout for electronically generating a call impedance in telephone appliances taps call alternating voltage between first and second input terminals while regulating impedance with a programmable digital filter.

摘要

A call alternating voltage (V/=) can be tapped between a first (a) and second (b) input terminal. A regulating device (2), having a programmable digital filter (4) for regulating impedance, includes a transmission function adjusted by programming the digital filter's coefficients. This filter can be incorporated as a digital signal processor or as a program in a digital signal processor.