A monolithic 2-b delta-sigma A/D converter

A monolithic 20-b analog-to-digital (A/D) converter using oversampling techniques which is implemented in standard 3- mu m CMOS technology is described. The integrated circuit contains a fourth-order delta-sigma modulator and a digital finite-impulse-response filter and decimator. The modulator consists of a continuous-time chopper-stabilized front end, and a switched-capacitor loop filter and comparator. The dynamic range is 123 dB over a DC-to-500-Hz bandwidth, and the signal-to-noise-harmonic-distortion ratio is 126 dB. The chip consumes 125 mW power and has an area of 29.25 mm/sup 2/.<
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