TPS23525: OR-ing FET characteristics

Kazunori Hayami

Part Number: TPS23525

Hello.
I understand that the external FET used in the TPS23525 for OR-ing operation is used to control the FET current by the gate-to-drain voltage, with the current flowing from the source to the drain. However, Power MOSFETs usually have an asymmetric drain-source structure, and the datasheet does not assume a case where current flows from the drain to the source, and the ON resistance, Vgs-Id (Vgd-Is?) characteristics, and Gm are not specified. Please advise me how I should consider the FET characteristics for this kind of reverse usage in general.

over 2 years ago

0 Avishek Pal over 2 years ago

TI__Mastermind 39820 points

Thanks for reaching out to us.

The ORing FET is selected based on the following criteria.

FET RDSON
VGS voltage rating
VDS rating

Please click on "This resolved my issue" if this post answers your query.

0 Kazunori Hayami over 2 years ago in reply to Avishek Pal

Prodigy 70 points

Thank you for your response.
I wanted to ask the following points.
-The FETs used in the ORing circuit must have the reverse current direction from the normal usage.
-The FET datasheet describes the forward characteristics (FET RDSON, VGS voltage rating, VDS rating), but not the reverse direction.
-Is it correct to assume that the characteristics (FET RDSON, VGS voltage rating, VDS rating) for the reverse direction of the FET current are the same as for the forward direction? Or should we check with the manufacturer?
I am waiting for your answer.

0 Avishek Pal over 2 years ago in reply to Kazunori Hayami

TI__Mastermind 39820 points

Please discuss these questions with the FET manufacturer. I am not an expert in MOSFET.

0 Avishek Pal over 2 years ago in reply to Avishek Pal

TI__Mastermind 39820 points

Please click on "This resolved my issue" if this post answers your query.

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TPS23525: OR-ing FET characteristics