Low-power design of low-voltage current-mode integrators for continuous-time ΣΔ modulators

Abstract

In this paper, we present a method to design low-power low-voltage current-mirror based integrators for continuous-time /spl Sigma//spl Delta/ modulators. It is shown that, by proper biasing of the mirror transistors, very high modulation index can be achieved at low-voltage supply. Careful analysis of the current-mode integrator shows that there exists an optimum supply voltage for minimum power consumption. Simulation results show that proper choice of the supply voltage can reduce the power consumption of the integrator by 40%.