BOOSTXL-PGA460: Powering large ultrasonic transducer?

Hi Chris,
With respect to high power ultrasonic applications, the PGA460 is best option for driving an ultrasonic transducer.
We have not used the PGA460 is this type of application, so I am unable to comment on the feasibility of this project, but I don't want to discourage you from trying.

The Steminc SMBLTF40W30NH transducer you have identified calls for a maximum input voltage of 950Vpp.
Considering your supply is at 12V, and most ultrasonic sensor center-tap transformers we use have a turns ratio of 1:1:10, the excitation voltage at the transducer will only be ~240Vpp (at most). I recommend that you start with this configuration. If the driver is too weak to be detected through 15m of ice, you may need to consider the following driver options:

To increase the transducer excitation voltage close to the transducer's maximum of 950Vpp, you will need a different center-tap transformer (i.e. 1:1:40 turns ratio for ~960Vpp maximum at 12V CT) or use a pre-driver with the original transformer. The PGA460's OUTA/B pins are limited to a maximum of 30V, meaning the center-tap of the transformer cannot exceed 15V. To apply more than 15V at the center-tap of the transformer, you can use the PGA460's OUTA/B pins as predrivers for external FETs with a larger voltage rating. E.g., if you continued to use a transformer with a 1:1:10 turns ratio, you would need a center tap voltage of 47.5V. Your external low-side FETs should be rated with a Vds of 50V in this example. To see a schematic implementation of the pre-driver transformer mode, see the PGA460 Full-Bridge Driver Solutions for Ultrasonic Transducers AppNote ( www.ti.com/.../slaa780.pdf ). In short, you ill need to connect the transformer's primary outer windings to the drains of the low-side FETs, the gates to the OUTA/B predriver outputs, and the sources to ground.