Ultra96: Peak current for pin 37 of LS expansion header

Hello fellow members.

Looking to use this pin to power external module.

What is the peak current rating for pin 37 of the Ultra96’s LS EXP HDR? The 96Board spec states a minimum of 5W (implying 1A).

It looks like the regulator is IR38060MTRPBF, which is capable of delivering 6A max.
But keep in mind that;

  1. That supply powers the entire board, which means that you definitely don’t have the full 6A available at that pin.
  2. You probably don’t want to pull its full capacity continually.
  3. There is no documentation on how much current the traces can handle.
  4. Designing beyond the 96boards specifications will lock you in to the specific board you are currently working with – other boards, current or future, may not be able to support your application.

My recommendation, if you need to go beyond 1A on that pin, is to take the power from SYS_DCIN (7W) and add your own regulator. If you need to go beyond 7W, then add a barrel jack to your mezzanine and power the SBC FROM YOUR BOARD through the SYS_DCIN pins on the LS connector. This option provides you with a power budget that is effectively unlimited – your power supply and board design become the limiting factors.

  1. There is no documentation on how much current the traces can handle.

Quite so. <1A should be safe since it is required by the standard and >2A is beyond the capabilities of the connector and should definitely be avoided.

The gap in the middle is up to the base board designer (it is OK for them to exceed the spec :wink: ). Obviously mezzanine boards that demand 1A would not be standards compliant… but if they are self-built and only target a specific base board that might not matter.

Thanks guys for the prompt feedback - much appreciated!

One more suggestion – make sure you are using the 4A AC/DC supply and not the 2A version.

Will do… Thanks Bryan.