Subscriber line interface circuitry with current drivers for downstream voice and data signals

摘要

A subscriber line interface circuit apparatus includes an impedance bridge coupled to a subscriber line. A first pair of current drivers is coupled to the impedance bridge for driving a voice signal in a first frequency range onto the subscriber line. A second pair of current drivers is coupled to the impedance bridge for driving a data signal in a second frequency range onto the subscriber line. The impedance bridge couples the second pair of current drivers to the subscriber line across an output impedance of Z 1 +Z 2 within the second frequency range.