Novel noise shaping of cascaded sigma-delta modulator for wide bandwidth applications

Author

Chiang, Jen-Shiun ; Chang, Teng-Hung ; Chou, Pou-Chu

Author_Institution

Dept. of Electr. Eng., Tamkang Univ., Tamsui, Taiwan

Volume

3

fYear

2001

fDate

6/23/1905 12:00:00 AM

Firstpage

1379

Abstract

In this paper, a novel noise shaping of cascaded sigma-delta modulators is proposed. Two stages are incorporated in this sigma-delta modulator. The first stage is realized by a feedforward architecture and the second stage is realized by a low-order single-loop architecture. Unlike the conventional feedforward sigma-delta architecture, we use a 1.5-bit quantizer in the feedback to substitute for the multi-bit DAC to make implementation very easy. However, it is necessary to add error cancellation schemes in the digital part to cancel the coarse quantization errors. By these arrangements, the architecture can reduce the oversampling ratio effectively and the in-band noise can be suppressed significantly to achieve high resolution. Simulation shows this sigma-delta modulator can achieve very good efficiency in wide bandwidth applications

Keywords

cascade networks; circuit simulation; error correction; feedforward; integrated circuit noise; interference suppression; sigma-delta modulation; 1.5-bit quantizer; cascaded sigma-delta modulator; coarse quantization errors; error cancellation schemes; feedforward architecture; in-band noise suppression; low-order single-loop architecture; noise shaping; noise transfer function; oversampling ratio; wide bandwidth applications; Bandwidth; Circuit noise; Delta-sigma modulation; Frequency; Multi-stage noise shaping; Noise reduction; Noise shaping; Sampling methods; Signal resolution; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics, Circuits and Systems, 2001. ICECS 2001. The 8th IEEE International Conference on

Print_ISBN

0-7803-7057-0

Type

conf

DOI

10.1109/ICECS.2001.957471

Filename

957471