@article{discovery10195902, note = {This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions.}, year = {2024}, month = {July}, title = {A High-Voltage Differential SPDT T/R Switch for Ultrasound Systems}, journal = {IEEE Transactions on Circuits and Systems I: Regular Papers}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {1549-8328}, keywords = {Bipolar-CMOS-DMOS (BCD), MOSFET switch, high-voltage analog switch, single-pole double-throw switch, transmit/receive switch, ultrasound hand gesture recognition}, author = {Zhang, Yaohua and Jiang, Dai and Demosthenous, Andreas}, abstract = {An improved bootstrapped circuit topology is proposed for the design of a high-voltage, differential, single-pole double-throw transmit/receive switch for an ultrasound hand gesture recognition system. The differential transmit/receive switch is designed in a 0.18 {\ensuremath{\mu}} m HV BCD technology. It is intended to interface with bimorph piezoelectric micromachined ultrasonic transducer electrodes, although a single-ended version can also interface with conventional ultrasound transducers. A comprehensive analysis has produced useful insights, namely the dependence of off-isolation on high-voltage input slew rate, and the dependence of common-mode rejection ratio on threshold mismatch and timing misalignment. In addition, an extended model has been developed to predict harmonic distortion through a DMOS transistor. Measured results verify the effectiveness of the design guidelines and switch operation. The switch circuit exhibits 67 ? on-resistance and ? 63 dB off-isolation while occupying a modest area of 289 {\ensuremath{\mu}} m {$\times$} 295 {\ensuremath{\mu}} m. The switch achieved a figure-of-merit with 74\% improvement over the state-of-the-art. To the best of the authors' knowledge, this differential switch is the first of its kind reported for piezoelectric micromachined ultrasonic transducer biomedical ultrasound systems.}, url = {https://doi.org/10.1109/tcsi.2024.3426558} }