Tool/software:
Hi!
We have successfully developed a battery powered amplifier PCBA utilizing the TPA3255 and are using this to drive a magnetostrictive actuator with frequencies of 200Hz-3kHz (impedance of load changes significantly over frequency range 1Ω-80Ω). Our client is interested in driving a different actuator and has found that providing a DC offset current aligns the magnetostrictive material and provides better output characteristics when driving this new actuator with the AC drive signal from the amplifier. Our client is interested in a 10VDC output into a coil with approximately 1Ω resistance (10A, 100W). He is interested in varying the DC current depending on frequency such that the DC voltage may vary from 4V to 8V with the desired capability up to 10VDC. My understanding is that the TPA3255 cannot provide a DC offset on the output. Do you have any suggestions on methods to intentionally add a DC offset voltage on the output of the TPA3255 circuit?
We can potentially utilize a 1:1 transformer on the output with a variable DC power supply. My concern is that this relatively high DC current may cause saturation of the transformer and therefore we won't be able to adequately transfer the output from the TPA3255 across the transformer (we could potentially use a very large transformer, but this isn't ideal). We are currently utilizing 1x TPA3255 but the client is interested in implementing two TPA3255 in parallel (I think this has been discussed before on the forums and it is possible to connect the output of the two ICs but only after the output LC filter) and then adding this DC offset capability as well. It is possible we may need to consider utilizing a class A/B amplifier solution and if so, does TI have any solutions that have similar output performance with a DC capability (700-1000W overall output, 100-3kHz frequencies, we are providing the TPA3255 with 54V).
Interested in hearing any ideas you may have to accomplish the DC output along with the TPA3255 IC or if you have any suggestions for other amplifier solutions that have the capability for amplifying DC and the 100-3kHz AC signal with the desired output power capability.
Thanks for your help!
