Half-bridge driver with charge pump based high-side voltage regulator

This paper presents a half-bridge driver to fulfill the requirement for interfacing with MEMs sensors. The upper switch of the driver is implemented by a p-type power transistor to make the driver feasible for pulse density modulated input signal. The high-side “ground” reference voltage VSSH is regulated through the proposed charge pump circuit, which harvests the charges flowing into the VSSH node and boosts them to the supply of the power stage VHV. The charge pump is designed with reversion loss prevention function to achieve a voltage difference close to VDD between VHV and VSSH. The driver is fabricated using the 0.18-µm CMOS process with 24-V LDMOS devices. The measurement results confirm the validation of the half-bridge driver with power efficiency up to 95%.