New Proposed Second-Order ASDM Using OTAs

Abstract

In this work, we present a new proposal for the second-order Adaptive Sigma Delta Modulation (ASDM). The new proposed Adaptation scheme is based on using Operational Transconductance Amplifier (OTAs) as an Integrator and as an Amplifier to adapt the quantizer step-size to control the voltage gain by feedback the quantizer output through adaptation scheme. The step-size is changing up or down by the output voltage of the integrator for every clock period. A comparison with general second-order SDM proves that our idea about using OTAs to achieve a high resolution and confirm the signal-to-noise ratio is better than GSM.