TPS2640: Reverse Input Supply Protection: UVLO, OVP, and SHDN pins

Jorge Vallejera Valdueza

Prodigy 30 points

Part Number: TPS2640

Tool/software:

Hi,

I´m going to introduce the component TPS26400 in our design.

I have a doubt about these pins UVLO, OVP, and SHDN regarding the reverse input supply protection.

In datasheet it is specified that this IC has integrated reverse input polarity protection down to –42V, but in the point 7.1 "Absolute Maximum Ratings" it is specified these values for that pins:

They don´t accept negative values. Only IN and OUT pins.

I have these schematic:

Will I have problems with that pins?, or they are protected too against reverse input supply?

2 months ago

0 Amrit Jit 2 months ago

TI__Genius 16301 points

Hello Jorge,

Welcome to e2e.

Reverse polarity protection is between GND and RTN pin.

Since all other pins (UVLO,OVP) are connected wrt RTN so reverse voltage won't have impact on them.

You can use UVLO for EN pin for TPS2640. How are you planning to use SHDN pin here?

Thanks

Amrit

0 Jorge Vallejera Valdueza 2 months ago in reply to Amrit Jit

Prodigy 30 points

Hi Amrit,

SHDN is connected to IN through a pull-up resistor. There isn´t any other control to this pin. Therefore I understand that it is protected too against reverse voltage, isn´t it?

Best Regards

0 Amrit Jit 2 months ago in reply to Jorge Vallejera Valdueza

TI__Genius 16301 points

Hello Jorge,

If you have provisions to change in your schematic, you can leave SHDN floating.

Recommended operating voltage of SHdN is 4V.

Thanks

Amrit

+1 Jorge Vallejera Valdueza 2 months ago in reply to Amrit Jit

Prodigy 30 points

You have reason. I will leave it unconnected because I need that this IC will be always ON. It has an internal PU to AVDD.

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TPS2640: Reverse Input Supply Protection: UVLO, OVP, and SHDN pins