A Fully Integrated Bipolar 1.8Vpp-to-41Vpp 450kHz Switched-Capacitor MEMS-Driver with a Power Reduction Factor of 16.3

This work presents a fully integrated bipolar switched-capacitor driver for ultrasonic Micro-Electro-Mechanical Systems (MEMS) transducers, capable of generating boosted amplitude modulated signals from a low supply voltage. The proposed architecture consists of a bipolar series-parallel charge pump (SP-CP) that generates positive and negative single-ended output voltages. This almost doubles the peak-to-peak output voltage and the power reduction factor compared to conventional unipolar SP-CPs. The bipolar SP-CP achieves better stage utilization, saving up to 50% in number of stages.