LMZ10504: LMZ10504 EN pin connection plan

yamashita-yukiya

Part Number: LMZ10504
Other Parts Discussed in Thread: TPSM82816, TPSM82813, TPS62140, TPS746

Tool/software:

Thank you for your continued support.

The attached circuit is one that starts up the output of U98/U116/U117 with a delay after power-on (+5V applied).

I would like to confirm this.

Is there any problem with connecting this type of circuit to the EN pin of U117 (LMZ10504TZX-ADJ/NOPB) in the overall circuit?

I am asking because I have no experience connecting in parallel with the EN pins of other LDOs or DC-DC converters like this.

+1 Chris Glaser 10 months ago

Hi,

Thank you for your question.

Yes, standard EN inputs like these can be connected together.

The LMZ10504 is quite old and large. Would the TPSM82816 work instead?

As well, the TPS62140 provides a 17Vin rating, which is not needed for a 5V rail. Would the TPSM82816 or TPSM82813 work instead?

Both of those devices have a SS pin. They also feature a precise EN input, which helps control the delay timing: https://www.ti.com/lit/an/slyt730/slyt730.pdf

Would the TPS746 LDO work for you in place of ADM7171?

Thanks,

Chris

0 yamashita-yukiya 10 months ago in reply to Chris Glaser

Thank you for your continued support.

Thank you for contacting us.

I understand that there is no problem with the connection of the EN input pin.

Thank you also for letting me know about alternative parts.

I will consider this in my next design.

Thank you very much for all your help.

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