TPS23751: TPS23751 option 3 oring techniques question

allen

Part Number: TPS23751

Dear Sir

My customer use TPS23751 and use types of option 3 oring techniques on their design,

but when I review their circuit, their Rden1 & Rden2 didn't follow below design, they use RDEN1 16.2K & RDEN2 8.87K it were cause any risk?

Allen

over 6 years ago

0 Darwin Fernandez over 6 years ago

TI__Mastermind 41770 points

Hi Allen,

the 13k ohm is important. Note the PSE MUST reject anything lower than 15k. So you want to be below 15k ohms. However, if too low, then the power dissipation gets higher and the resistor power rating must increase. I recommend sticking with the solution we recommended. Note the 1/4W 13.7k ohms resistor is important. Thanks!

0 allen over 6 years ago in reply to Darwin Fernandez

Intellectual 360 points

Hi Darwin

You mean in my customer design, if DEN1 higher then 15K ohm, the PSE will continue powerd PD, but DEN is connect to GND, the hotswap mos will disable.

And I right?

Thanks!!

0 Darwin Fernandez over 6 years ago in reply to allen

TI__Mastermind 41770 points

Hi Allen,

Just to clarify, yes the hotswap will disable and PSE will remove power. However, after PSE power removal, the PSE may try detection to see if PD is connected. When this happens, you want the PSE to reject the PD and not try to turn back on. This is why we choose lower than 15k since per the standard the PSE must reject this detection resistance and the PSE indeed doesn't try to re-power the PD when the adapter is connected.

Thanks!

0 allen over 6 years ago in reply to Darwin Fernandez

Intellectual 360 points

Hi Darwin

Thank you for your quick reply. I fully understand.

Thanks a lot.

Allen

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TPS23751: TPS23751 option 3 oring techniques question