Improved null cancellation in a 6TH-order Σ-Δ modulator realized with two 3RD-order sections
Document Type
Conference Proceeding
Date of Original Version
1-1-2002
Abstract
This paper presents an improved method to digitally eorreet for static, analog circuit imperfections in a two-stage, (i " order, cascaded (6-3) sigma-delta modulator. Bv adding a digital correction term to the output of the digital noise cancellation filter, the first stage parasitic quantization noise due to finite amplifier gain and C-Ratio mismatches can be completely removed. A (>-3 modulator implemented as a fully differential switchcd-capacitor circuit , designed for an OSR of 16. has been fabricated in a 1.2 μm double-poly n- well CMOS process. Improvements have been made in t he null cancellation leading to approximately a 10 (IB increase in SNDR over a range of signal amplitudes from 12 μVolts to 500 niY. A peak SNDR/SFDR of 87/100 (IB for a 1 MHz sample rate and 84/93 (IB for a 2.5 Mlfz sample rate have been achieved.
Publication Title, e.g., Journal
4th IMEKO TC4 Conference on Advanced A/D and D/A Conversion Techniques and Their Applications and the 7th Workshop on ADC Modelling and Testing 2002
Citation/Publisher Attribution
Davis, Alan J., Godi Fischer, Hans H. Albrecht, and Jürgen Hess. "Improved null cancellation in a 6TH-order Σ-Δ modulator realized with two 3RD-order sections." 4th IMEKO TC4 Conference on Advanced A/D and D/A Conversion Techniques and Their Applications and the 7th Workshop on ADC Modelling and Testing 2002 (2002). https://digitalcommons.uri.edu/ele_facpubs/221