Safe Operating Voltage for STHV800 in Fault Scenarios

[raghavendrap]

Greetings Community,

I am using the STHV800 ultrasound pulser in the analog front-end of an ultrasound imaging application. In my setup, I pulse at ±50V, generating a 3-cycle biphasic signal at 5.2 MHz for transmit. The transducer is connected via a 2-meter twisted pair cable; 70-ohm impedance match.

I am evaluating potential fault scenarios where:

1. Some transducer elements may be shorted to ground.
2. Some transducer elements may be open.
   To ensure the safety and longevity of the STHV800 under these conditions, I would like to understand the following:
   1. What is the maximum safe voltage I can pulse at without damaging the pulser in these fault scenarios?
   2. Does the STHV800 have any built-in protection mechanisms or considerations for handling short-to-ground or open-circuit conditions?

Thank you for your assistance!

Best regards,
Raghavendra Padmanabha

[Tifidutail]

Dear Sir

I am using the STHV800 and I am facing random issues. Some IC can burn and I don’t understand the reason why. And I cannot succeed in burning any more pulsers during my tests. I suspect too high voltage, but it may be overheating issues, too high current, ESD discharge, manufacturing issues (welding…) …

Have you any feedback you could share?

The application is related to ultrasound, with frequencies between 0.5 MHz to 20 MHz ?

Regards

Tifidutail

[raghavendrap]

Hi @Tifidutail 

Thanks for the note. I have used the STHV800 with a center frequency around 6 MHz. Your symptoms match what I have seen when the pulser is run near its limits or when the load is not well controlled.

A few ideas to check
• Reflections from poor termination or long cables can spike the output.
• Excess current from a shorted or partially shorted channel.

What does your setup look like? (TX voltage, mono or biphasic, frequency, impedance, load) You could also characterize the channel impedance as seen by the pulser across your band using a network analyzer.

best,
Raghav