Other Parts Discussed in Thread: , CSD18531Q5A
Hi TI guys.
I'm coming from company from Slovenia and I'm a firmware and hardware developer.
Our goal is to make a device which is capable of continuously supplying 100W from the USB-C connection. We have working example of our own design with TPS55288RPMR IC, running at 400 kHz, and practically everything works except that at max. power (around 100W) mosfets get too hot. We're using the reference design from the TPS55288EVM-045 evaluation board. Currently we get the best results with CSD18531Q5A mosfets, but when we check the PCB with a thermal camera we can clearly see that the TPS55288 is also getting too hot, probably because of gate charge of the two mosfets). The problem is really just at high output loads (>70W).
As much as I can tell, I see the problem in the gate-source capacitance, which is in our case around 3200pF @ 1MHz (from the datasheet). Compared to the IPZ40N04S5L-7R4 (the one used in the TPS55288EVM-045) which is 690pF @ 1MHz.
When we rise the frequency to the 2MHz everything gets much worse, which is logical. Now my question for you is:
Can you please suggest us the best mosfet (part numbers) that's in stock and it would work like original IPZ40N04S5L-7R4 that is used on the evaluation board (which work perfect event at max. load)? Problem is that the original part from Infineon is out-of stock everywhere...
p.s.
The coil used in 400 kHz case is: XAL1010-472ME, for 2MHz case is from Wurth Elektronik - 74439358010.