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Ultrasonic shaker

Brian Wang0928
Genius 11650 points
Other Parts Discussed in Thread: LM4766, TPA3255

Hello, 

We're looking for a solution for the Ultrasonic shaker as below diagram. Is there any suggestion on the Class AB AMP to amplifier the signal from +/-10V to +/-100V?

  • 0
    TI__Mastermind 20830 points

    Hi Brian,

    An output voltage of +/-100V is going to limit your options greatly. The highest voltage our devices are able to output are at about 60V like the LM4766. I'm sure you can lower the voltage requirements with a different transformer though?

    Also another alternative is to change the design to a digital input Class-D amplifier! That way you can remove the DAC! Just something to think about while you are still this early in the design.

    Best Regards,

    Robert Clifton 

  • 0 in reply to Robert Clifton56
    TI__Genius 11650 points

    It looks that Class-D amp is also a good ideal but it should need higher voltage at next stage, TPA3255 should be ok, right? If Cass-D amp is selected，there are few questions for TPA3255：

    1. How much lowest load impedance is able to drive? Is it able to drive 2Ω load? Customer thinking to utilize Transformer to replace speaker. 
    2. Is TPA3255 able to connected in parallel with 2 units to driver higher power？

    Regards

    Brian W

  • 0 in reply to Brian Wang0928
    TI__Mastermind 20830 points

    Hi Brian,

    TPA3255 might be able to work for your application. I'm glad you're considering it. To answer your questions: 

    1. The lowest impedance is actually 1.7ohms if you configure the output in PBTL mode. 

    2. We have studied it in the past but have found that you can't do that safely. Essentially there's no safe way of ensuring all of the FETs are able to equally share the current. This has lead to parts getting destroyed as a result. 

    Best Regards, 

    Robert Clifton