A 700 mW CMOS line driver for ADSL central office applications

Abstract

A dual-channel analog front-end for ANSI/ETSI standards compliant VDSL in 0.25/0.5/spl mu/m 1P 5M CMOS is presented. The chip includes a non-linearity cancelling multi-path line driver achieving -76dBc 3rd harmonic distortion at 12MHz, a 75mW continuous-time multi-bit 3rd-order self-calibrating /spl Sigma//spl Delta/ ADC, a 14b current-steering DAC with PSD mask post filter, a 0-35dB variable-gain amplifier with adjustable hybrid, and a 12ps jitter LC PLL.