TPS2384: Requirement of Fuse

Anand Krishnan M

Part Number: TPS2384
Other Parts Discussed in Thread: TPS23861, TPS23882, TPS23881EVM-008, TPS23881

Hi TI Team,

We are using TPS2384 quad PSE for a POE application project containing 4 Ethernet ports.In the datasheet of TPS2384 (http://www.ti.com/lit/ds/symlink/tps2384.pdf), the over-current limit for each port is mentioned as (400 mA to 450 mA).If the current is above this limit corresponding port is shutdown.In the example circuit given in datasheet a resettable Polyfuse of at least 1A is recommended.Please refer the following images.

May I know the purpose of this fuse, since the TPS2384 shutdowns port when an Over current detects ?

Regards

Anand

over 5 years ago

0 Darwin Fernandez over 5 years ago

TI__Mastermind 40660 points

Hi Anand,

Today is a national holiday in the US. We will be able to have answer for you when our applications engineers are back from holiday. Thanks!

0 Penny Xu over 5 years ago

TI__Genius 15655 points

Hi Anand,

The fuses add additional protection the to system and improve the system's robustness. It is not a must have. We usually see customers having the fuse in the system and you may need to do less test to pass UL testing. May I know get better idea of your system?

What is your max port power needed?
Do you have a host to communicate with TPS2384?

We have newer PSE parts TPS23861,TPS23882(coming soon) may be a better choice (easier hardware design and cheaper price) for you. Thanks.

Best regards,

Penny

0 Anand Krishnan M over 5 years ago in reply to Penny Xu

Prodigy 40 points

Hi Penny,

Thanks for your feedback.

1. 10W , PoE IP camera applications ,Cameras uses 802.3af standard.

2. No.We are using it in standalone mode.

0 Penny Xu over 5 years ago in reply to Anand Krishnan M

TI__Genius 15655 points

Hi Anand,

You can use TPS23881 for your design as it has autonomous mode and requires much simpler hardware design.It is also cheaper than TPS2384 even it is a 8 channel device. Please take a look at TPS23881EVM-008. We will have a low cost version(TPS23883) for <30W only application coming out 3Q this year and it is pin to pin compatible with TPS23881. Thanks.

Best regards,

Penny

0 Anand Krishnan M over 5 years ago in reply to Penny Xu

Prodigy 40 points

Thanks Penny

I will look into it.

Regards

Anand

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TPS2384: Requirement of Fuse