TPA3255: TPA3255 or TPA3116D2 at 100 kHz

Bob Kemp Jr

Part Number: TPA3255
Other Parts Discussed in Thread: TPA3116D2

Hello,

We have successfully used your TI TPA3255 Class-D Power Amplifier using a step-up transformer to increase the voltage and match the high impedance of a piezoelectric underwater acoustic transducer in the 43 kHz range. We now need a Class-D Power Amplifier, also for a high impedance piezoelectric underwater acoustic transducer, to operate in the 50 kHz to 100 kHz range.

The power level of the TPA3255 is about right. Can it be made to operate from 50 - 100 kHz ? Or is there something better ?

We were also looking at your TPA3116D2 with its 1.2-MHz Switching Frequency, thinking that it might be better from 50 - 100 kHz, but it doesn't have the needed power level. Could two of them be operated in a bridge fashion to double the power ?

What is your best product recommendation that could be used for high power Class-D applications like this up to 100kHz ?

Thanks for your help.

over 3 years ago

0 Wei Qiu over 3 years ago

TI__Expert 5690 points

Hi Bob.

Signal Bandwidth up to 100 kHz for High Frequency Content From HD Sources.---TAS3255

The TPA3255 can be operated in the 50kHz to 100kHz range. We don't have any other class D amp similar to TPA3255's power level.

Could two of them be operated in a bridge fashion to double the power ?--- We don't have this usage.

BR.

Wei Qiu.

0 Bob Kemp Jr over 3 years ago in reply to Wei Qiu

Prodigy 45 points

Hello,

Can you please suggest an output filter design for the TPS3255 that will pass 100 kHz, but that will not violate the minimum 5uH inductor requirement ?

0 Wei Qiu over 3 years ago in reply to Bob Kemp Jr

TI__Expert 5690 points

Hi Bob.

You can take the file below as a reference.

LC Filter Design (Rev. A) (ti.com)

Meanwhile, you can also use the design tool below to do some calculation.

LCFILTER-CALC-TOOL Design tool | TI.com

BR.

Wei Qiu.

0 Bob Kemp Jr over 3 years ago in reply to Wei Qiu

Prodigy 45 points

Hello,

Using the LC Filter Design Excel tool, his is what I come up with.

Is this about the best we could expect operating from 50 kHz to 100 kHz; and not going below 5uH ?

0 Wei Qiu over 3 years ago in reply to Bob Kemp Jr

TI__Expert 5690 points

Hi Bob.

This is only the result of ideal calculation and is provided for customer's design reference only. In practice, the inductance and capacitance will have many parasitic parameters, and the actual device selection needs to be adjusted.

BR.

Wei Qiu.

0 Bob Kemp Jr over 3 years ago in reply to Wei Qiu

Prodigy 45 points

Hello,

With all of that being said, should we be able to get the TPA3255 to work from 50 kHz to 100 kHz without violating the >= 5uH inductance requirement ? Do you have any other suggestions for us to be successful with this ?

0 Wei Qiu over 3 years ago in reply to Bob Kemp Jr

TI__Expert 5690 points

Hi Bob.

I think the output filters you calculated above is okay.

We suggest you to use the calculated filters to replace the output filters of our EVM board to confirm it can be successful.

BR.

Wei Qiu.

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TPA3255: TPA3255 or TPA3116D2 at 100 kHz