LM74700-Q1: Question Asking

Jason Ciou

Part Number: LM74700-Q1
Other Parts Discussed in Thread: LM5118, LM74610-Q1, , LM74500-Q1

Hi team,

My customer use LM5118 buck-boost converter and he wants to do the Reverse polarity protection, and I only find this document

https://www.ti.com/lit/ug/tiduc53/tiduc53.pdf?ts=1630566043281&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTIDA-01179

For my customer specification Vin: 24V to 48V Vo: 54V Io: 1.2A

The document use LM74610-Q1, but its voltage range is 0.48V to 42V.

So I find the LM74700-Q1 to replace the LM74610-Q1, I want to check with team, Is it ok my customer using LM74700-Q1 in this circuit?

Or do you have any suggestions about Reverse polarity protection in my customer case.

over 2 years ago

0 Praveen GD over 2 years ago

TI__Guru 57737 points

Hi Jason,

Yes LM74700-Q1 can be used for input reverse polarity protection. It can withstand +/- 65V at its input.

Please select an appropriate TVS diode at the input such that during all conditions (especially transient) the voltage across the input of the LM74700-Q1 is within its Absolute Maximum rating.

In case only reverse polarity is required and reverse current blocking functionality is not required, you can also consider using LM74500-Q1.

0 Jason Ciou over 2 years ago in reply to Praveen GD

TI__Expert 3600 points

Hi Praveen,

Thanks for your reply,

I only need to change the LM74160 to LM74700 right?

Do I need to change Q3? in my customer case

Jason

+1 Praveen GD over 2 years ago in reply to Jason Ciou

TI__Guru 57737 points

Hi Jason,

Can this device be subjected to any automotive transients at the input ? The FET voltage rating and the input TVS selection depends on the automotive transients that can occur at the input. Please refer to datasheet for datasheet and TVS selection guidelines.

0 Jason Ciou over 2 years ago in reply to Praveen GD

TI__Expert 3600 points

OK, I got it.
Thanks.

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LM74700-Q1: Question Asking