A standard low-noise sensor interface for 0.66nJ/step-energy-efficient, mobile barometric-pressure-based altitude sensing

This paper presents a mixed-signal sensor interface IC on only 1.5mm²-silicon that delivers almost 16-bit-precise measurement results for resistive bridge-type sensors. The IC integrates a programmable ratiometric analog interface and contains a digital calculation unit for sensor-nonlinearity and temperature dependency compensation. A low-dropout regulator allows the usability of a respective smart sensor in dirty-supply applications without requiring external stabilization components. The IC allows for a new performance level of mobile barometric pressure sensing due to the combination of external component-free power supply rejection, specific analog/digital signal processing and a stringent energy efficiency approach. A figure-of-merit of only 0.66nJ/step is achieved. The absolute accuracy of ±0.5hPa can lead to altitude measurements in the range of -500m to 10km with 8cm-resolution.