High Pass Filter Implementation Comparison in Unity STF High Pass $\Delta \Sigma$ Modulator
Résumé
High-pass (HP) delta-sigma (ΔΣ) modulators enjoy
superiority over low-pass (LP) ΔΣ modulators because
of their inherent immunity to low-frequency noise. HP filter
is a major building block of HP ΔΣ modulator. This article
presents three state of the art HP filters accompanied by their
detailed comparative analysis. They are compared on the basis
of switch noise, Operational Transconductance Amplifier (OTA)
noise and OTA finite dc-gain, finite gain-bandwidth product
(GBW) and finite slew rate (SR). This in-depth analysis is
validated by simulation results and proves that the improved
structure provides superior performance than the other two HP
filter implementations. It achieves better noise immunity and
relaxes the OTA requirements.