Yes the 802.3bt PSE & PD. LTC4291/LTC4292 and LT4321.
LT4321 has a thermal resistance, junction to case, θJC = 4.5° C/W. The θJA = 47° C/W you mentioned is based on a JEDEC 4 layer board.
Please note, LT4321 is an Ideal Diode Controller. As such, it consumes very little power even during full load…
The DC2685 is the demo board for the LTC4291-1/LTC4292 and is a PSE.
The LT4321 is an ideal diode controller, not a PD controller.
I recommend the DC2583A, LT4294 IEEE 802.3bt PD interface demo board for evaluating the PSE.
2) use LTC4266A4 for PSE, LTC4275A for PD. Datasheet for LTC4266A does not mention the Ilimit for 90W
3) PD uses LTC4275A and LT4321 as development board connected with LTPoE++.PHY on PD is isolated from PoE through the network transformer…
Do you know if there is a new POE solution coming out of the Analog Devices / Linear Tech merger? Basically I am thinking of a LT4295 solution use iCoupler Analog Devices technology. Currently to do this I would need to combine the LT4294 with…
I've answered your questions below.
1. Flyback Converter VOUT
You may need to adjust the RC Snubbers, but the first thing you should change is the feedback divider. Change R10 to get 28Vout. This transformer will be fine with this new output.
IEEE 802.3af/at/bt requires the PD to be capable of receiving power from either pairset, the data or spare pairs, and to polarity correct the input. Polarity correcting requires a diode bridge, and receiving power from both pairsets requires two…
in this case I'm trying to understand what could caused explosion of the chip. The relevant portion of the schematics looked like this:
In these conditions the chip was kept in shutdown, because the internal pullup in LT4321 raised voltage…