Title :
Implementation aspects of an oversampling D/A converter for DMT-ADSL systems
Author :
Gao, Yonghong ; Tenhunen, Hannu
Author_Institution :
ESDLab, R. Inst. of Technol., Stockholm, Sweden
Abstract :
This paper presents a 5th-order single-bit oversampling sigma-delta digital modulator for D/A conversion with 1.1 MHz signal bandwidth for DMT-ADSL application. To meet different SNDR requirements, the oversampling ratio is chosen to be 24, 32, 48 and 64 respectively. Feedback coefficients in the modulator are carefully obtained from the simulated results for good stability and in-band performance. Low power consumption is achieved by scaling down the internal word-length of each integrator of the modulator. A modulator with an oversampling ratio of 32 and 14-bit input has been integrated into a D/A conversion chip implemented in a 0.6 μm 3.3 V CMOS process
Keywords :
CMOS integrated circuits; circuit feedback; digital subscriber lines; digital-analogue conversion; low-power electronics; modulators; sigma-delta modulation; 0.6 micron; 1.1 MHz; 14 bit; 3.3 V; 5th-order modulator; CMOS process; D/A conversion; DMT-ADSL systems; SNDR requirements; feedback coefficients; integrator; low power consumption; oversampling D/A converter; oversampling DAC; oversampling sigma-delta modulator; single-bit type; stability; Delta-sigma modulation; Digital filters; Digital modulation; Feedback; Finite impulse response filter; Low pass filters; Noise shaping; Quantization; Stability; Transfer functions;
Conference_Titel :
Electronics, Circuits and Systems, 1999. Proceedings of ICECS '99. The 6th IEEE International Conference on
Conference_Location :
Pafos
Print_ISBN :
0-7803-5682-9
DOI :
10.1109/ICECS.1999.814430
