Design and electrical implementation of a 1.8-V multistandard switched-current ΣΔ modulator

Abstract

This paper describes the design and electrical implementation of a 1.8-V, 0.18mm CMOS reconfigurable switched-current SD modulator for multistandard (Bluetooth, WCDMA) communication systems. The modulator topology is an expandible cascade architecture which can be reconfigured both at the architecture level and at the circuit level in order to adapt the modulator performance to the different standards with adjustable power consumption. For this purpose, programmable Class AB memory-cell arrays are used to implement the modulator loop filter. Simulation results are shown that demonstrate correct operation for all standards, featuring 11bits dynamic range within 1MHz and 7.8bits within 3.8MHz bandwidth.