A 2.54μJ∙ppm2-FOMS Supply- and Temperature-Independent Time-Locked ΔΣ Capacitance-to-Digital Converter in 0.18-μm CMOS

Abstract

In this paper, we propose a time-locked ΔΣ CDC (TLΔΣ CDC) that achieves the state-of-the-art FOMS=2.54µJ∙ppm 2 , supply sensitivity of ±0.55%/V over 1.2-2.2V and temperature sensitivity of 49.1ppm/°C over -20°C and 125°C. The sensing resolution is 70.5aF. Implemented in a 0.18µm standard CMOS process, the TLΔΣ CDC consumes 42.76µW from a 1.2V supply and 0.2mm 2 active area.