ADSL front-end for broadband communications

A novel low-power low-voltage 0.25 µm CMOS ADSL analog front-end with 2.5 V power supply was developed. The analog front-end consists of amplifiers, filters, converters, and a tunable oscillator. The amplifiers feature highly accurate programmable gain. The filters for up-stream and down-stream feature highly accurate programmable cutoff frequencies. The switched current high speed digital-to-analog converter has 12 bit resolution @ 8.8 MHz sampling rate and 1 Vpp. The pipelined high speed analog-to-digital converter has 13 bit resolution @ 8.8 MHz sampling rate and 1 Vpp. All components feature high linearity and low noise. A novel triple-well mixed signal technique with separated power supplies has been applied.