A 13.5-bit cost optimized multi-bit delta-sigma ADC for ADSL

A high-resolution multi-bit ΣΔ ADC architecture for operation at low oversampling ratios is introduced. An area-efficient implementation of a 3
^rd
-order 7-bit modulator, avoiding pipeline latency effects, is presented. Clocked at 26 MHz, the 0.6µm CMOS, dual-stage ΣΔ ADC achieves 83 dB SNR over a 1.1 MHz signal bandwidth.