A 187dB FoMS 46fJ/Conv. 2nd-order Highpass Δ∑ Capacitance-to-Digital Converter

The proposed capacitance-to-digital converter (CDC) achieves 187dB $\mathrm{FoM}_{\mathrm{S}}$, which is >2x improvement over the state-of-the-art, with $\mathrm{FoM}_{\mathrm{W}}$ of 46fJ/Conv.-Step. We employ a highpass $\Delta\Sigma$M in CDC applications for the first time while using loop filters based on power-efficient floating inverter amplifiers (FIAs).