%X This paper presents a differential T/R SPDT switch, designed in a 0.18 μm HV BCD technology for PMUTbased biomedical ultrasound systems. It incorporates a bootstrapping technique to pass high-voltage pulses and a shunt branch for improved isolation. The differential T/R switch is designed to interface with bimorph electrodes although a singleended version can also interface with conventional PZT/CMUT transducers. Post-layout simulation results show that the switch circuit exhibits 64 Ω on-resistance and -62 dB off-isolation. A figure-of-merit is proposed to compare ultrasound T/R switches. To the best of the authors' knowledge, this differential switch is the first of its kind being reported for PMUT biomedical ultrasound systems. %C Singapore %O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. %I IEEE %S IEEE International Symposium on Circuits and Systems (ISCAS) %L discovery10195904 %K CMOS integrated circuit, human-machine interface, PMUT, SPDT switch, T/R switch, ultrasound hand gesture recognition %J Proceedings - IEEE International Symposium on Circuits and Systems %D 2024 %A Y Zhang %A D Jiang %A A Demosthenous %V 2024 %T A Differential SPDT T/R Switch for PMUT Biomedical Ultrasound Systems %B Proceedings of the 2024 IEEE International Symposium on Circuits and Systems (ISCAS)