A novel micropump driver used in environmental sensor applications

The reaction times of environmental sensor units are potentially improved by the use of micropumps. Those micropumps require miniaturized driver electronics which generate dual-polarity high voltage pulses optimized to drive light, capacitive load piezoelectric micropumps. This paper presents a novel micropump driver consisting of a DC/DC converter circuit that is based on a combination of a boost converter and a charge pump. This combination generates asymmetric high voltages on two individual synchronous output nodes from a 5-V supply. Through reduction in the number of coils this method supports the overall system shrinking and allows a high level of chip integration. Compared to state-of-the-art miniaturized drivers, the presented topology allows single-ended and differential micropump driving at higher voltage levels (-100 V/+150 V). By connecting the micropump differential to the converter output, the maximum voltage can be increased to 250 V for capacitive micropump loads of up to 200 nF. The converter topology was validated by measurement. The presented novel, miniaturized micropump driver topology allows micropump integration into mobile devices for new fields of sensor applications with rapid reaction times.