Other Parts Discussed in Thread: PMP7282, LMC7101
Hi support team,
My customer is following PMP7282 to do a 600W interleaving design using LM5116, but they found a issue during the startup where the master phase MOSFET will get overheated at full load startup.
The PMP7282 uses LMC7101 from Master's COMP1 pin to control the slave's FB pin, however in configuration only Master phase will be switching at first because the REF2 will be pull-up by the COMP1 immediately while SS2 is ramping, REF2 will be much higher than SS signal which the slave phase will no switch until SS signal exceeded REF2.
This caused an overheating issue for the master phase during the full load startup, and my customer need to pick much higher rating MOSFET to survive the startup phase.
Please see waveform below:
The slave only started to switching when SS exceeds FB2 i.e. when COMP2 rises.
Is there any better way to implement the interleaving circuit using LM5116? any reference design my customer can follow?
I am thinking instead of using the internal EA of slave controller, does it work by grounding the FB2 pin of the slave (or provide a small offset) and use an op-amp to pull-down the COMP2 to follow COMP1?
Many thanks.
Best Regards,
Wei-Hao
