A new compact, low on resistance and high off isolation high voltage analog switch IC without using high voltage power supplies for ultrasound imaging system

摘要

This paper presents a new high voltage analog switch IC for ultrasound imaging system. Compact analog switch IC that doesn't need dedicated high voltage power supplies is strongly required because it can contribute to reducing size and cost of ultrasound imaging system. To satisfy above requirements, we propose a new floating gate driving circuit and a new switch circuit. To reduce die size of IC, we used finer pattern process based on SOI process. In addition, we optimized the thickness of gate oxide film and breakdown voltage of MOSFETs to reduce on-resistance. Developed IC can transmit +/-100V high voltage signal with 18ohm on-resistance and less than -50dB off isolation performance is realized. Developed IC realized the same die size as the conventional IC by optimizing the structure of MOSFETs. Moreover, power consumption of the developed IC can be reduced about 90% compared to that of the conventional IC.