Designing Complex ΔΣ Modulators with Signal-Transfer Functions having Good Stop-Band Attenuation

This paper presents design methods for delta-sigma (ΔΣ) analog to digital (A/D) converters having signal-transfer functions (STFs) with improved out-of-band signal attenuation. The trade-off between the improved attenuation of the STF and achieving a noise-transfer function (NTF) that optimizes the SNR of the A/D converter is made explicit.