Title :
A novel low-voltage 2nd-order sigma-delta modulator with double-sampling for GSM/DECT/WCDMA
Author :
Chio, Kinsang ; Martins, R.P. ; U, Sengpan
Author_Institution :
Fac. of Sci. & Technol., Univ. of Macau, Macao, China
Abstract :
This paper presents the design of a double-sampling multilevel sigma-delta modulator (SDM), with relaxed operational amplifier requirements, for GSM/DECT/WCDMA communication standards. The modulator operates with 1.8 V voltage supply (with chopper stabilization technique) and has been implemented in 0.35 μm CMOS. A novel dynamic element matching (DEM) technique is introduced for a double-sampling SDM. The moving sum effect resulting from the fully floating switched-capacitor integrator in the feedback path has been reduced in order that the noise shaping performance remains unchanged in the signal band. The achieved SNR are 88 dB/70 dB/55 dB for GSM/DECT/WCDMA, respectively.
Keywords :
CMOS analogue integrated circuits; cellular radio; choppers (circuits); circuit feedback; cordless telephone systems; integrating circuits; operational amplifiers; sigma-delta modulation; signal sampling; switched capacitor networks; 0.35 micron; 1.8 V; CMOS; DECT; GSM; WCDMA; chopper stabilization; double sampling; dynamic element matching; feedback path; fully floating switched-capacitor integrator; moving sum effect; multilevel SDM; noise shaping performance; relaxed operational amplifier requirements; second-order sigma-delta modulator; Choppers; Communication standards; Communication switching; Delta-sigma modulation; Feedback; GSM; Multiaccess communication; Noise shaping; Operational amplifiers; Voltage;
Conference_Titel :
Communications, Circuits and Systems, 2004. ICCCAS 2004. 2004 International Conference on
Print_ISBN :
0-7803-8647-7
DOI :
10.1109/ICCCAS.2004.1346378
