A novel approach to implement summing function for feedforward Δ-Σ AD modulator

Abstract

A novel approach is proposed to implement summing function for feedforward Δ-Σ modulator. Unlike the conventional methods, neither summing op-amp nor a large number of summing capacitors are used in our design. The high-accuracy summing function is accomplished by using a few capacitors with small size to compensate the summing error caused by parasitic capacitance, thereby resulting in a smaller chip area and no additional power dissipation. © IEICE 2008.