Tool/software:
Hello TI support team
I've got an issue around a TPS62110. I'm making a down conversion from 12V to 5V with an output max current of 1.2A.
I've got some ringing of the SW pin, only undershoot. The minimum voltage is -1.2V (using stats over a long period of integration)
Here is a zoom :
The probing is make with a custom 1:20 1kOhm passive probe (50ohm input scope to match the coax impedance in order to avoid reflection). With an active probe (ZS1000), the waveform is exactly the same (except some issue with scaling as this probe as got a range of +/-8V). Of course, very very small tip to probe it.
The max absolute ratings are overpassed for the SW pin (-1V).
In other DC-DC it's always written that this undershoot can be overpassed during 10ns for instance. But in the TPS62110 datasheet nothing.
In the TI forum, I've also read that this kind of switching node can go down -3V under 10ns pulse but with no formal specification on the datasheet.
So I would like to know is my design is risky ???
Otherwise, I have to add a snubber (the layout is exactly the one recommended in the datasheet, no improvement on this field). The RC will damp the undershoot but will decrease my efficiency (not yet tested).
Thanks for your answer.
