Tools For Automated Design of ΣΔ Modulators

We present a set of CAD tools to design ΣΔ modulators. They use statistical optimization to calculate optimum specifications for the building blocks used in the modulators, and optimum sizes for the components in these blocks. Optimization procedures at the modulator level are equationbased, while procedures at the cell level are simulation-based. The toolset incorporates also an advanced ΣΔ behavioral simulator for monitoring and design space exploration. We include measurements taken from two silicon prototypes: 1) a 17bit@40kHz output rate fourth-order low-pass modulator; and 2) a [email protected] central freq@10kHz bandwidth band-pass modulator. The first uses SC fully-differential circuits in a 1.2μm CMOS double-metal double-poly technology. The second uses SI fully-differential circuits in a 0.8μm CMOS double-metal single-poly technology. Foonote This work has been supported by the CEE ESPRIT Program in the framework of the Project #8795 (AMFIS) Tool s for Automated Design of ΣΔ Modulators 2 Workshop on Advances in Analog Circuit Design--Lausanne, 1996 Tools For Automated Design of ΣΔ Modulators