Design of semi-uniform quantizers and their application in sigma delta A/D converters
2004 (English)In: Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, E-ISSN 1573-1979, Vol. 41, no 03-feb, 253-267 p.Article in journal (Refereed) Published
In this paper a new type of non-uniform quantizer, semi-uniform quantizer, is introduced. A k-bit semi-uniform quantizer uses the thresholds defined by a (k+1)-bit uniform quantizer and arranges them in such a way that small-amplitude inputs will be quantized by small quantization steps and large-amplitude inputs by large quantization steps. Therefore the total quantization error power could be reduced and the modulator's dynamic range could be increased by 1-bit. The condition for a semi-uniform quantizer to achieve a better performance than a uniform quantizer is analyzed and verified using a second order 3-bit sigma delta modulator prototype chip, fabricated in 0.35 mum CMOS process. At 32 x oversampling ratio the modulator achieves 81 dB dynamic range and 63.8 dB peak SNDR with 3-bit semi-uniform quantizer. With 3-bit uniform quantizer the dynamic range is 70 dB and the peak SNDR is 54.1 dB.
Place, publisher, year, edition, pages
2004. Vol. 41, no 03-feb, 253-267 p.
sigma, delta, quantization, modulation, OTA, adc
IdentifiersURN: urn:nbn:se:kth:diva-23729ISI: 000223914200014ScopusID: 2-s2.0-4544387928OAI: oai:DiVA.org:kth-23729DiVA: diva2:342428
QC 20100525 QC 20110921. 9th IEEE International Conference on Electronics, Circuits and Systems, DUBROVNIK, CROATIA, SEP 15-18, 2002