A two-level, high voltage driver circuit with nanosecond delay for ultrasonic transducers

In this paper, a two-level, high voltage (HV) driver circuit for driving ultrasonic transducers is presented. The circuit is specifically designed to drive a Capacitive Micromachined Ultrasonic Transducer (CMUT). The driver circuit has no static power consumption from the high voltage power rails which makes it suitable for low power portable ultrasonic applications. The HV driver has a measured peak to peak voltage swing of 47 V at 1.8 MHz pulse frequency. The rise and fall times of the pulses are 78 ns and 67 ns respectively. The work also demonstrates the possibility to have a fully integrated front-end solution for CMUTs without the need to use an external DC bias. The total layout area of the driver circuit is 0.22 mm2. The presented circuit is fabricated using a $0.18 \mu \mathrm{m}$ HV SOI CMOS process.