A digitally-enhanced 2-0 ΔΣ ADC

Voltage supply scaling and wide signal bandwidth require that modern delta sigma (DeltaSigma) architectures surmount the low oversampling ratio (OSR) challenges with low- distortion design. An analog feedforward architecture (AFF) mitigates these issues by reducing the swing at the integrator outputs but requires an analog adder. A two-stage digitally enhanced 2-0 (DE2-0) architecture that employs digital addition and a FLASH ADC in the second stage is proposed. DE2-0 reaps the benefits of AFF, while eliminating the need for an analog adder and attaining a SNR of 63.5 dB at OSR of 10 for a 20 MHz input bandwidth, with 22.8% figure of merit (FOM) improvement over AFF.