Part Number:LM5161-Q1
Hi,
We got a question from the customer about LM5161-Q1.
Could you help us?
[Question]
They evaluated LM5161-Q1 in Fly-buck-boost topology on their own board. Before the IC starts switching in start-up, the negative voltage occurs on SW to GND. Please refer to the attached file for the details.
(Please visit the site to view this file)
- They assume this phenomenon occurs due to charge current flows through Cin to Cout. Is this their understanding correct?
- How is the level of negative voltage determined? They assume there are 2 factors.
1. The ratio of Cout to Cin.
2. Vf of the body diode on low side FET.
- Is there any solution to prevent the negative voltage beyond the rating of SW and damage to the body diode due to the rush current?
Best Regards,
tateo