1 Introduction

As the imaging technology is improving in ultrasound systems, there has been an increasing demand to fit more transducer elements along with HV switches in ultrasound probes, while keeping the same form factor. This need has driven to develop switches with high channel density which can be laid out compactly on the PCB with minimal effort.

To understand the use case better, look at how HV multiplexers and switches fit into a present-day ultrasound system. In this context, the multiplexer is responsible for connecting the transmit and receive circuitry to the transducers. The channels of the multiplexer are activated in turn to drive sequential sections of the probe elements. Each multiplexer channel passes the transmitter’s ±100V pulses to each piezoelectric element. When an element subsequently receives the return signal from the subject of imaging, the multiplexer also passes this signal back to the receiver circuitry for amplification, digital conversion, processing, and display.

Figure 1-1 Typical Block Diagram for 128 Channel Ultrasound System

For this application, TI recommends the TMUX9832 device, which is the latest beyond the supply 1:1 32 channel switch.