I have an LM3407 design that operates at low current. The inductor was chosen based on the datasheet equations and verified with the design calculator. The sense resistor waveforms look appropriate, and the current has been measured and appears to be as-designed.
We've seen numerous open-circuit inductor failures during long term testing, and are concerned that the current is going out of regulation and burning out the inductor. What circumstances could lead to the inductor current going out of regulation?
I can't provide specific design details on this forum, but I can send them in direct messages to TI staff.
(We're also pursuing this issue with the inductor manufacturer.)
Thanks!
