TPS2383 Recommended Transformer

user1293366

Other Parts Discussed in Thread: TPS23861, TPS23841, TPS2376

Hi ,

Can anyone please recommend the transformer that can work with KS8999 along with PoE? I want to use the following PoE PSE controller TPS2383.

The transformer used in KS8999 evaluation board is H1164. Which I believe is that it cannot be used to deliver PoE on the data pairs.

best regards,

Nomaan.

over 10 years ago

0 Darwin Fernandez over 10 years ago

TI__Mastermind 41760 points

Hi Nomaan,

TPS2383 is not recommended for new designs.

I recommend looking into our latest PSE TPS23861. Please see below.

You can reference its data transformer in the EVM and associated reference designs.

http://www.ti.com/product/tps23861?keyMatch=tps23861&tisearch=Search-EN-Everything

0 user1293366 over 10 years ago in reply to Darwin Fernandez

Prodigy 50 points

Hi Darwin,

Thanks for such a prompt reply. What I believe is that TPS23861 is one of the best option for us. However some PD devices works on 24V and I was wondering what if I opt for TPS23841 as it supports wide range single supply of 21.5V to 57V. Kindly suggest if I can use TPS23841 24V input.

best regards,

Nomaan.

0 Darwin Fernandez over 10 years ago in reply to user1293366

TI__Mastermind 41760 points

Hi Nomaan,

Yes, you can use a 24V rail to power the TPS23841 however you still need a 48V rail for the PoE power. Is it a limitation on the amount of power you can supply with the 48V rail that it can't power the IC which is why you need an extra 24V rail?

0 user1293366 over 10 years ago in reply to Darwin Fernandez

Prodigy 50 points

Hi Darwin,

What is bothering me is that if 48V rail is needed for the PoE power, then what's the use of operating TPS23841 at 24V rail when it works on single supply? Does TPS23841 have an in built step-up dc-dc converter that can step-up 24V to 48V? Furthermore why does TPS23841 offers such a wide range single supply?.

best regards,

Nomaan.

0 user1293366 over 10 years ago in reply to Darwin Fernandez

Prodigy 50 points

Hi Darwin,

Kindly reply to my last post.

best regards,

Nomaan.

0 Darwin Fernandez over 10 years ago in reply to user1293366

TI__Mastermind 41760 points

Hi Nomaan,

There is no step up converter inside the IC to output 48V. The TPS23841 is capable of outputing 24V (with 570mA ICUT min) to a port but operating at this low of voltage is not IEEE compliant. You may have interoperability issues as a compliant PD will accept between 37-57V depending on the power level.

If you are looking to implement non-standard solution (24V through ethernet cable). You can consider using the TPS2376 PD which has a UVLO pin for the PD to turn on at lower input voltages.

If you are looking for a 24V to 48V converter solution to make this solution compliant. TI Designs has many to choose from based on the power level. Below is the link to TI Designs.

http://www.ti.com/general/docs/refdesignsearchresults.tsp?powerlabflag=Y

0 user1293366 over 10 years ago in reply to Darwin Fernandez

Prodigy 50 points

Hi Darwin,

Thanks a lot.

best regards,

Nick.

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TPS2383 Recommended Transformer