A Differential Quantizer-Based Error Feedback Modulator for Analog-to-Digital Converters

Abstract

A differential quantizer-based error feedback modulator intended for digitizing analog signals and its comparison to the traditional interpolative sigma delta analog-to-digital conversion is presented in this brief. The differential quantizer-based error feedback modulator also falls under the class of noise-shaping data converters. This newly introduced technique replaces the integrator with a differential quantizer to achieve noise-shaping characteristics. Thus, integrator associated non-idealities, loop-stability issues, and optimization of the integrator scaling coefficients is no more a concern. Differential quantizer-based error feedback modulator technique can perform well in high-precision and low-power applications. Behavioral-level simulation results demonstrate the mathematical equivalence of the differential quantizer based error feedback modulator technique with interpolative sigma delta modulator technique and confirms its novelty, theoretical stability, and scalability to higher order. The circuit level feasibility and effectiveness of the proposed architecture is verified in a 45-nm CMOS process using a 1-V supply with a power consumption of 0.22 and 0.5 mW for the first and second order modulators, respectively.