Other Parts Discussed in Thread: UCC39002, , UCC29002, TPS40057
Tool/software:
I tried to post my question here Forum, but I think the thread is closed. The issue was:
We are using two TPS40054 chips to get 5.1V and 3.3V outputs, a UCC39002 for load sharing control, and a hot-swap controller for reverse current protection. Our design was working fine, but we had to replace the High- and Low-side FETs in the Buck converter from FDB13AN06A to IRF1018ES. We also replaced the UCC39002 surface-mount with a UCC29002 through-hole. The ratio between Qgs/Qgd is better in the Infineon MOSFETs than the Onsemi ones; however, we are encountering issues with the new MOSFETs. When we connect the load-sharing controller to the circuit, hot swap controller enters in fault mode. However, when we replace the new MOSFETs with the old ones, the problem seems to be resolved.
Additionally, the issue only occurs under no-load or light-load conditions; when we connect a certain load to the output, the power supply starts working again.
Do you have any information on how the MOSFETs and the load-sharing controller might be related in this context?
Infineon
OnSemi
I was wondering if we are using the TPS40054, which only source current to the output, and we are having issues with no load or light load conditions. Does it mean the controller is having issues with DCM? I was searching on the internet and I found out that TPS40054 may be unstable in DCM. Thread 2. We replaced the controller with a TPS40057 controller and the problem is solved.
