TPS2379: Contradiction between data sheets

Tyson Craven

Part Number: TPS2379

The data sheet in Table 1 gives the classification resistor possibilities as 63.4 Ohms, 90.9 Ohms, !37 Ohms, 243 Ohms or 1270 Ohms. The EVM datasheet says in section 3 that a shunt on J7 can be added to give 45.2 Ohms. But that is not one of the possible classification resistors. It seems to be a contradiction.

over 5 years ago

0 Thomas Amlee over 5 years ago

TI__Genius 9230 points

Hi Tyson,

Nice find! This resistor value is not a part of the . See the description for J7 on table 4. This resistance value was a hold over from a previous implementation of non-standard high power PoE, and NOT a part of the then current 802.3at standard, or upcoming IEEE 802.3bt standard.

Here's a video about non-standard PoE from a few years ago:
training.ti.com/high-power-poe-design-considerations

Thanks,
Tom

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TPS2379: Contradiction between data sheets