An Area-Efficient, Differential Resonant Ultrasound Pulser with 69% fCV² Dynamic Power Reduction

This paper presents a scalable, differential resonant pulser for wearable/portable ultrasound applications, such as hand gesture recognition for prosthesis control and gaming. Presently, the mainstream pulser topologies include the class-D amplifier, multilevel pulse shaping, charge-recycling, and LC-resonant. A resonant pulser topology is adopted because theoretical analysis has shown that the resonant pulser has an inherent power advantage over other types of pulsers. The current state-of-the-art resonant pulser, while achieving excellent fCV<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> power dissipation reduction, lacks scalability. This work aims to tackle this shortcoming by using high-voltage DMOS transistors in a more area-efficient manner. On average, the proposed circuit uses three DMOS transistors per single-ended transducer or six DMOS transistors per differential transducer, making the proposed circuit attractive for multi-channel systems. Post-layout simulation results show that the proposed differential resonant pulser can achieve 69% fCV<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> dynamic power reduction, which is comparable to the state-of-the-art. To the best of the authors’ knowledge, the proposed differential resonant pulser for ultrasound applications is the first of its kind.