A 0.8 V switched-opamp bandpass /spl Delta//spl Sigma/ modulator using a two-path architecture

In this paper, a very low-voltage fourth-order bandpass delta-sigma modulator with a two-path architecture is presented. Using the modified switched opamp technique enables the modulator to operate at only 0.8 V supply voltage without any voltage multiplier or bootstrapping switch. Realized in a 0.25 /spl mu/m 1P5M standard CMOS process, the prototype modulator exhibits a signal-to-noise-plus-distortion ratio (SNDR) of 60.6 db and a dynamic range (DR) of 68 db in a 30 kHz signal bandwidth centered at 1.25 MHz while consuming 2.5 mW and occupying an active area of 2.11 mm/sup 2/.