A Noise-Coupled Time-Interleaved Delta-Sigma ADC With 4.2 MHz Bandwidth, 98 dB THD, and 79 dB SNDR

This paper describes a wideband high-linearity ¿¿ ADC. It uses noise coupling combined with time interleaving. Two versions of a two-channel time-interleaved noise-coupled ¿¿ ADC were realized in a 0.18-¿m CMOS technology. Noise coupling between the channels increases the effective order of the noise-shaping loops, provides dithering, and prevents tone generation in all loops. Time interleaving enhances the effects of noise coupling. Using a 1.5 V supply, the device achieved excellent linearity (SFDR>100 dB, THD=-98 dB) and an SNDR of 79 dB in a 4.2 MHz signal band.