TPS92638-Q1:Fault output voltage

Ömer Kalayci

Prodigy 145 points

Other Parts Discussed in Thread: TPS92638-Q1, TPS92633-Q1

Parça Numarası: TPS92638-Q1

Preliminary information

My IC (TPS92638QPWPRQ1) supply voltage will be 28V (Vsupply: 28V)

The MCU I use is powered by 5V.

I'm thinking of pulling the fault pin to pull-up externally with 5V, but I have some concerns (picture-1)

Fault pin internal structure; The fault pin seems to be pulled-up internally with Vsupply (picture-2)

Question1-) Is the connection type shown in picture-1 correct?

Question2-) Is there a possibility that the fault pin will give voltage higher than 5V and corrupt the MCU? (pic-1 // While Vssupply assuming 28V)

picture-1

picture-2

over 2 years ago

0 Gracie Guo over 2 years ago

TI__Genius 11146 points

This is an English forum. If this question is urgent, could you please use English?

For these 2 questions, I suggest pull-up resistor to be 10k ohm. No harm to MCU here. You may refer to TPS92633-Q1 schematic.

BR, Gracie

0 Ömer Kalayci over 2 years ago in reply to Gracie Guo

Prodigy 145 points

There was a mistake in my post, I've fixed it now.
my question is urgent
I would appreciate if you reply again according to TPS92638-Q1, thank you so much master

+1 Gracie Guo over 2 years ago in reply to Ömer Kalayci

TI__Genius 11146 points

TPS92633-Q1 is the next generation of TPS92638-Q1. They share the similar internal fault scheme. You may refer to this application schematic as an example. No harm to MCU. But the external pull-up current needs to be lower than the min value of pull-down current. So the pull-up resistor needs to be >= 10k ohm.

BR, Gracie

0 Ömer Kalayci over 2 years ago in reply to Gracie Guo

Prodigy 145 points

Thank you very much for your reply.

Putting 10k or not doesn't change anything because I think it has an internal pull-up

I understand if I want to ignore errors I should use a resistor less than 5k I would appreciate it if you chek me (pic.3)

thank you so much sensei

Picture-3

+1 Gracie Guo over 2 years ago

TI__Genius 11146 points

Yes. It has a weak internal pullup. So your understanding here is right.

BR, Gracie

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TPS92638-Q1:Fault output voltage