TPS1HA08-Q1: Unused pin recommendation : Float or GND with pull-down

Motoyasu Hattori

Part Number: TPS1HA08-Q1

Hi,

I want to ask one topic.

According to datasheet P.5, we can find the description "Float or ground through Rprot resistor" on "Connection if not used" column. Which do you recommend "Float" or "GND with pull-down"?? Also, please let us know the reason to select.

He is thinking "Float", however he wants to know the merit/demerit.

Thanks and best regards,
M.HATTORI.

over 5 years ago

0 Anthony P Pham over 5 years ago

TI__Mastermind 23410 points

Hi Hattori-san,

The reasoning for the Rprot resistors being pulled to ground is to help dissipate the current that would be present in a reverse battery or reverse current event. If there is no additional external protections against reverse current, we do recommend these resistors as there is an internal pulldown on these I/O pins.

0 Motoyasu Hattori over 5 years ago in reply to Anthony P Pham

TI__Genius 10935 points

Hi,

If my customer does not use LATCH pin, treatment of this pin is "Floating". Is it OK??
If any concern, please advise us the reason.

Thanks and best regards,
M.HATTORI.

0 Anthony P Pham over 5 years ago in reply to Motoyasu Hattori

TI__Mastermind 23410 points

Hi,

Leaving the LATCH pin floating is fine.

As mentioned, the option to ground through Rprot is used to protect pins from excess current flow in the reverse battery condition.The concern is if there is no resistor, the internal pull down to ground will damage the Latch pin ESD cell.

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TPS1HA08-Q1: Unused pin recommendation : Float or GND with pull-down