TPS2373: If use Adapter ORing option 1 mode, will the hotswap MOSFET of TPS2373-4 work as ON state and have 0.1 ohm resistance as typ value?

Zhizhao Niu

Part Number: TPS2373

Hi team,

Nice to meet you. I receive a question about TPS2373-4 using adapter oring option 1 configuration.

My customer wonder if use the "Adapter Oring" function optional 1. How is the internal hotswap MOSFET statue? Will this MOSFET in ON state and keep a typical Rdson=0.1Ω？

over 5 years ago

0 Michael Pahl over 5 years ago

TI__Mastermind 21320 points

Hello,

From datasheet section 7.4.9 PD Hotswap Operation:

The hotswap switch will be forced off under the following conditions:

1. VAPD above VAPDEN (approximately 1.65 V),

2. V(DEN –VSS) < VPD-DIS when V(VDD-VSS) is in the operational range,

3. PD is over-temperature, or

4. V(VDD –VSS) < PoE UVLO falling threshold (approximately 32 V).

So if the customer is using an adaper, APD > VAPDEN and the FET will be turned off. So it will be high impedance.

If the customer is using PoE, then the FET will turn on.

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Zhizhao Niu over 5 years ago in reply to Michael Pahl

TI__Expert 4400 points

Hi Michael,

Thanks for your reply!

Sorry I didn't understand it. If the MOS is turned off, the adaptor will be disconnected from the circuit. If adaptor disconnect from the circuit, how to power the system in that case?

Thanks!

B.R.

Zhizhao

0 Michael Pahl over 5 years ago in reply to Zhizhao Niu

TI__Mastermind 21320 points

I am sorry I misread your question.

If you are doing option 1, the Hotswap FET will be on.

The following paper goes into more depth in the PSE and Adapter Input OR-ing options.