A 94dB SFDR 78dB DR 2.2MHz BW Multi-bit Delta-Sigma Modulator with Noise Shaping DAC

A 5
^th
- order multi-bit lowpass delta-sigma modulator employs a proposed noise shaping dynamic element matching (NSDEM) technique to remove DAC non-linearity error. Unlike most existing DEMs trading SNR for SFDR, the proposed technique improves both SFDR and SNR The noise shaping is incorporated in the first integrator of the loop filter without any additional analog circuitry. The fabricated modulator chip achieves 94dB SFDR and 78dB DR in 2.2 MHz BW and meets the ADSL2+ specifications.