Comunicación presentada al "38 th MWSCAS" celebrado en Rio de janeiro del 13 al 16 de Agosto de 1995.This paper presents a fourth-order bandpass sigma-delta modulator that has been designed using fully-differential switched-current circuits in a 0.8μm CMOS technology. The modulator prototype has been obtained by applying a lowpass to bandpass transformation to a second-order lowpass ΣΔ modulator. Specifications are SNR 60dB@2.5Mhz±15Khz, for a clock frequency of 1OMhz. Preliminary results from the fabricated prototype obtains the correct noise shaping up to 2.5Mhz clock frequency.Peer reviewed