A 20 μA Front-End for Three-Axis Capacitive Microaccelerometers

This paper presents the measurement results of a micro-power differential switched-capacitor front-end designed for three-axis capacitive microaccelerometers. The designed front-end is capable of reducing the distortion effects of the electrostatic forces. The front-end was realised with a 0.13 μm CMOS process. The silicon area of the front-end is 0.30 mm². The measurements show that the functionality of the front-end follows the theory and that it achieves the noise densities of 490 μg/√(Hz), 595 μg/√(Hz) and 595 μg/√(Hz) in the x-, y-and z-directions, respectively, when each mass is sampled at 1 kHz. The current consumption from a 1.8 V supply is 20 μA, when four masses are read.