Title :
A CMOS oversampling D/A converter with multi-bit semi-digital filtering and boosted subcarrier SNR for ADSL central office modems
Author :
Lin, Andrew C Y ; Su, David K. ; Hester, Richard K. ; Wooley, Bruce A.
Author_Institution :
Stanford Univ., CA, USA
Abstract :
An oversampling D/A converter for use in ADSL central office modems has been integrated in 0.18-μm CMOS technology. The converter features a resampled, multibit semidigital filter for reconstruction and a digital pre-emphasis filter that flattens the overall in-band magnitude response and boosts the SNR of subcarriers affected by noise shaping. When sampling at 200 MHz, the converter achieves 86 dB of dynamic range for a 1.1-MHz bandwidth, with an average MTPR of 73dBc.
Keywords :
CMOS digital integrated circuits; digital filters; digital subscriber lines; digital-analogue conversion; modems; 0.18 micron; 1.1 MHz; 200 MHz; ADSL; CMOS oversampling D/A converter; central office modems; digital preemphasis filter; in-band magnitude response; noise shaping; semidigital filtering; subcarrier SNR; Bandwidth; CMOS technology; Central office; Digital filters; Dynamic range; Filtering; Modems; Noise shaping; Sampling methods; Signal to noise ratio;
Conference_Titel :
VLSI Circuits, 2005. Digest of Technical Papers. 2005 Symposium on
Print_ISBN :
4-900784-01-X
DOI :
10.1109/VLSIC.2005.1469349
