A High-Voltage TX/RX Switch with 3.3-V Supply for Ultrasound Imaging Front-End ASICs

This paper proposes a novel switch implementation for enabling transmitting and receiving (TX/RX) through one single wire in ultrasound imaging transceivers. The proposed structure consists of a resistor and two current sources controlled by a DC loop. This implementation allows driving the primary switch with the low-voltage (LV) power supply available for the transceiver front-end, while providing isolation to the front-end from the high-voltage (HV) pulses required for driving the transducer in TX mode. Furthermore, by employing a DC control loop, the design not only ensures off-isolation, but also allows having zero leakage current. The proposed TX/RX switch has been designed in a 160-nm bipolar-CMOS-DMOS silicon-on-insulator (BCD-SOI) technology with a 3.3-V supply voltage. Simulation results of the proposed structure confirm its effectiveness in achieving isolation voltages of up to 200 V peak-to-peak at 3-MHz operational frequency with -42-dB off-isolation.