Analysis of op-amp phase margin impact on SC ΣΔ modulator performance
✍ Scribed by Andrea Pugliese; Francesco A. Amoroso; Gregorio Cappuccino; Giuseppe Cocorullo
- Book ID
- 104053535
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 1011 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0026-2692
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✦ Synopsis
The impact of operational amplifier (op-amp) phase margin on switched-capacitor (SC) sigma-delta modulator (SDM) performance is investigated in this paper. An ad-hoc integrator settling model is developed and verified by circuit simulations performed in a commercial 0.35 mm CMOS technology.
The model allows the effect of op-amp phase margin to be taken into account in SDM behavioural analysis. Behavioural simulations of a typical single-bit second-order modulator are presented, as an example. As shown, the proposed analysis allows well-found specifications for the op-amp unity-gain frequency, slew rate and phase margin to be defined since the preliminary behavioural simulation phase.