Fully integrated charge pump for high voltage excitation of a bulk micromachined gyroscope

The paper describes fully integrated excitation electronics, which enables quick start-up or powerful continuous stage drive of a resonating sensor. The system of a micromechanical resonator, readout circuitry and high voltage drive electronics is connected to form a positive feedback from the capacitive readout of the sensor to the drive electrodes. The charge pump circuit converts the low voltage signal at the resonant frequency to a 20 V differential square wave. The functionality is verified by forming a positive feedback loop and measuring the start-up time of a bulk micromechanical gyroscope. The measured charge pump is implemented within a chip area of 0.46 mm² and draws 0.9 mA from a 5 V supply.