%T A High-Voltage Differential SPDT T/R Switch for Ultrasound Systems
%A Yaohua Zhang
%A Dai Jiang
%A Andreas Demosthenous
%D 2024
%J IEEE Transactions on Circuits and Systems I: Regular Papers
%K Bipolar-CMOS-DMOS (BCD), MOSFET switch, high-voltage analog switch, single-pole double-throw switch, transmit/receive switch, ultrasound hand gesture recognition
%L discovery10195902
%I Institute of Electrical and Electronics Engineers (IEEE)
%O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
%X 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 μ 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 Ω on-resistance and − 63 dB off-isolation while occupying a modest area of 289 μ m × 295 μ 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.