PoE PSE requirement

David Pfaltzgraff

Other Parts Discussed in Thread: TPS2384, TPS23841

In looking through the lierature, it seems that I have an unusual requirement and I'd like some pointers/ideas.

The requirement is for a device with a single ethernet port to provide power to the port. The requirement is for 48V up to 100mA to be available. I could use the TI TPS2384 but that supports 4 ports and I only need one.

Also, any suggestions for a +12V to -48V conversion? It seems that most of the devices and/or designs are much heftier (1A or more!). In this application board space is at a premium and I'd like to keep it as small a possible.

Along the way I need to make sure that the design remains IEEE 802.3at (or appropriate letter) compliant.

Thanks

over 12 years ago

0 Eric Wright over 12 years ago

TI__Mastermind 42795 points

Please refer to the following E2E thread which discusses the use of TPS2384 (and TPS23841) in a single port application. PMP5480 which is embedded in the thread shows the configuration of TPS2384 in single port applications (auto mode).

http://e2e.ti.com/support/power_management/power_interface/f/204/p/234951/833607.aspx#833607

For the 12 to 48V power supply, take a look at the links below. For the negative 48V you can ground the high side as this is an isolated design.

http://www.ti.com/tool/pmp2000 or http://www.ti.com/tool/pmp7132

And, you can refer to the TI power lab reference design pages for other solutions

http://www.ti.com/lsds/ti/analog/powermanagement/reference_design.page