TI TPA3255EVM

You need to make sure, your rails wont hit any limit specified in the datasheet. Your rails aren't just PVDD set by the supply (i.e. 50V) it also includes pumping effects and overshoot.

With a bad/unregulated supply you may experience some sag which might get modulated by connection wire inductance and bulk capacitance. This need to/should be measured directly at the chip pins.
 
Of course not. It's a trade-off between ease of completion and squeezing the last bits out of the system. With the added question of how much you truly benefit from that last few watts before having the police called on you. :) I'm probably going to pick a couple 3255's up and run it as 4x SE + 2 BTL in an active system. Massive overkill, but hard to justify not going for the 3255's over the 3251's at the same cost.
 
You can use the current limit programming resistor.

Approximation of datasheet values for CB3C:

attachment.php


170Wrms is about 340Wpk so at 4R there will be:

SQRT(340Wpk/4R) = 9.2A -> 41kOhms -> 39kOhms choosen to have some headroom.
 

Attachments

  • TPA3255_CB3C.png
    TPA3255_CB3C.png
    9.9 KB · Views: 3,275
Last edited:
This was a "buy one get three more free" deal over 10 years ago -- 48V Sorensen supplies which have been sitting on a shelf. They would seem to be OK for this project Evaluation Module project. I think I almost tried to give them away at one time -- no takers:
 

Attachments

  • Sorensen_A.jpg
    Sorensen_A.jpg
    146.1 KB · Views: 1,121
  • Sorensen_B.jpg
    Sorensen_B.jpg
    163.8 KB · Views: 1,100