Title :
Sigma-delta analog to digital converter architecture based upon a modulator design employing a mirrored integrator
Author :
Ignjatovic, Zeljko ; Bocko, Mark F.
Author_Institution :
Dept. of Electr. & Comput. Eng., Rochester Univ., NY, USA
Abstract :
We present a method to increase the resolution and stability of ΣΔ analog to digital converters in which the entire ΣΔ modulator is enclosed in a chopper-stabilization (CHS) structure. Simulations of the proposed architecture show that the effects of integrator opamp non-idealities (1/f noise, DC offset and drift) and digital-to-analog converter (DAC) DC offset and even-order distortion harmonics are eliminated and that the effect of integrator saturation distortion is reduced by up to 27dB in comparison to existing designs. Finally, the proposed architecture may be realized in a single-ended design enabling area-conservative circuit layouts.
Keywords :
1/f noise; harmonic distortion; integrated circuit layout; mixed analogue-digital integrated circuits; operational amplifiers; sigma-delta modulation; ΣΔ modulator; 1-f noise; DC offset; analog-digital converter; chopper-stabilization structure; digital-to-analog converter; distortion harmonics; integrator opamp; integrator saturation distortion; mirrored integrator; modulator design; Analog-digital conversion; Choppers; Circuits; Computer architecture; Delta-sigma modulation; Digital modulation; Frequency; Harmonic distortion; Low pass filters; Sampling methods;
Conference_Titel :
Circuits and Systems, 2004. ISCAS '04. Proceedings of the 2004 International Symposium on
Print_ISBN :
0-7803-8251-X
DOI :
10.1109/ISCAS.2004.1328399