A Current Regulator for Inverter-Based Massively Column-Parallel $\Delta \Sigma$ ADCs

The inverter-based switched-capacitor delta-sigma (ΔΣ) analog-to-digital conversion (ADC) has become popular due to its low-voltage low-power capabilities. This brief proposes a new current regulation technique for the inverter-based circuits. The proposed circuit controls both the power supply and the common-mode levels in response to the process-voltage-temperature variations by sensing the current in the replica inverter. The proposed sense and regulation circuit is implemented for the regulation of massively column-parallel ΔΣ ADCs, and the measurement results prove that the performance is well controlled regardless of the variations.