A broadband high-voltage SLIC for a splitter- and transformerless combined ADSL-Lite/POTS linecard

Abstract

A monolithic broadband subscriber line interface circuit (B-SLIC) has been integrated in the smart power technology SPT170B, combining the functionality of an analog 150-V ringing SLIC with that of a line driver for ADSL-Lite data signals. Thus the B-SLIC is the key circuit for the realization of a very compact integrated voice data (IVD) central office linecard that neither needs analog filters ("POTS-splitter") nor transformers or relays. In spite of the fundamental voltage/frequency tradeoff, the B-SLIC is able to feed high dc or ring voltages to the line, while simultaneously acting as voice and data transceiver. Total harmonic distortion values are below -60 dB even for a high 25-V/sub pp//550-kHz sine wave signal into a 200 /spl Omega/ load; ADSL-signal-based multitone power ratio (MTPR) measurements also yield results better than 60 dB. Power dissipation in simultaneous voice and data operation is about 2.2 W.