TPS54394 unsed power good pin

Eng Lih Khaw

Expert 2000 points

Other Parts Discussed in Thread: TPS54394, TPS54395

Hi,

I like to seek advise pertaining the TPS54394 unused Power Good pin (PGx):

- Is it possible to leave those pins 'floated' or Not connect? or they have to be connected to a capacitor and grounded (like the soft start pin implementation)

- Should the pins left floated, would it caused any noise?

Thanks in advance!

over 12 years ago

0 JohnTucker over 12 years ago

TI__Guru**** 191445 points

It is ok to leave the PG outputs floating and not used.

0 Eng Lih Khaw over 12 years ago in reply to JohnTucker

Expert 2000 points

Hi,

Thanks for your answer.

Could you advise if it's OK to connect the Power Good pin to a capacitor then to GND. (same implementation as Soft Start pin). Reason being is that my customer port over their design from TPS54395.

Thanks!

0 JohnTucker over 12 years ago in reply to Eng Lih Khaw

TI__Guru**** 191445 points

I have not tried that. I would suggest that they just de-populate the capacitor for TPS65394 design. They will need a pull up for the PG signal though. See the EVM users guide to see how we accommodate both ICs on a single PCB.

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TPS54394 unsed power good pin