HD3SS3412: HD3SS3412 SEL pull High & Low resistance

Hugo Liu

Genius 5095 points

Part Number: HD3SS3412
Other Parts Discussed in Thread: TPS65988

Hi Sir,

The HD3SS3412 datasheet is show the SEL pull Low resistance 100k to GND.

and TPS65988 Evaluation Module show the SEL pull High resistance is 1k.

But our customer used 28 units on PCIE switch, so some one HD3SS3412 need Synchronize SEL pin control with system,

Resistance maybe have Series Parallel change the value,

Could you please provide the pull High & Low Resistance value range for me? we need to Calculation value to customer.

Hugo

over 6 years ago

0 Brian Zhou over 6 years ago

TI__Guru*** 146535 points

can you draw simple schematic or application?

0 Hugo Liu over 6 years ago in reply to Brian Zhou

Genius 5095 points

Hi Brian,

This is riser card in application Storage.

Could you please provide the SEL pull High & Low Resistance range for me?

If our customer want to use the MOSFET or GPIO to control SEL High/Low status, is this any risk on SEL?

Hugo

0 Lee Sledjeski over 6 years ago in reply to Hugo Liu

TI__Mastermind 43795 points

Hi Hugo,

The typical value for the internal pulldown on SEL is 100K Ohms. The lowest resistance value to GND based on the datasheet specification of 95uA @ 3.6V is approximately 38K Ohms.

I do not see any risk of a GPIO driving the SEL pin.

Regards,

Lee

0 Hugo Liu over 6 years ago in reply to Lee Sledjeski

Genius 5095 points

Hi Lee,

Thank you very much.

Hugo

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HD3SS3412: HD3SS3412 SEL pull High & Low resistance