High-pass or low-pass ΣΔ modulators?

In this paper, High-Pass (HP) ΣΔ modulators are compared to the traditional Low-Pass (LP) ΣΔ modulators. The objective of this comparison is to point out the advantages and drawbacks of the two modulators thereby allowing to choose the most suited for a given application. The metrics of comparison are the noise floor, power consumption, surface area and the effect of the non-idealities of all the basic blocks (i-e Operational Transconductance Amplifier (OTA), Quantizer, Switches and Clocks). It turns out that HP modulators are more suited for narrow band applications because of their immunity against DC-offset and flicker noise. For medium and wide band applications, LP modulators are preferred because of their higher robustness against switch imperfections and clock jitter.