A High Dynamic Range and Low Power Consumption Audio Delta-Sigma Modulator with Opamp Sharing Technique among Three Integrators

A low power and high performance with third order delta-sigma modulator for audio applications, fabricated in a 0.18µm CMOS process, is presented. The modulator utilizes a third order noise shaping with only one opamp by using an opamp sharing technique. The opamp sharing among three integrator stages is achieved through the optimal operation timing, which makes use of the load capacitance differences between the three integrator stages. The designed modulator achieves 101.1dB signal-to-noise ratio (A-weighted) and 101.5dB dynamic range (A-weighted) with 7.5mW power consumption from a 3.3V supply. The die area is 1.27mm2. The fabricated delta-sigma modulator achieves the highest figure-of-merit among published high performance low power audio delta-sigma modulators.