we designed a 4-phase layout with the LTC3874 in a 2/4 phase arrangement. Everything seems to perform like expected but the inductors getting really hot when using FCC with no load connected.
The design is made with the following specs:
FET/Sync: Toshiba TPH2R506PL
inductors: Coilcraft XAL1580 3uH
Using Burst-Mode or Pulse-Skip of course wont heat up the inductors. Any hint? I can't see any frequency-jitter, compensation seems to work fine as well (with rather low bandwidth of roughly 4kHz (70+dB PM) at 10V VIN). The loop compensation is design made with LTPowerCAD.
Iripple is about 13A per phase at VIN=10V, shouldn't be an issue for the inductors.
I haven't spoken to my local FAE as this is a proof of concept student project which may go into production in the future. (No time to market yet)
Best regards, Christian