LMR62421: circuit breakdown

Nicolas Casella

Part Number: LMR62421

Hi,

I have an issue with a circuit implementing LMR62421XSD/NOPB.
It is used to boost voltage from 5V to 18V. The 18V is delivered to 3 LDOs. The circuit was designed with Webench, with a small reduction of the inductance.
The circuit works fine, but breaks after some uses, currently it is tested without loads (only LDOs). With the final application the load will be <50mA, with an average of 20mA.
The supply is a bench supply of 5V, which works properly.

Have you got any suggestions or debug steps?

BR,
Nicolas

over 4 years ago

0 Brigitte over 4 years ago

TI__Guru 65170 points

Hello Nicolas,

Please share your schematic, if possible with the LDOs.

What exactly do you mean with breaks after some uses? Could you possibly measure the input and output voltage at the moment when it breaks down?

0 Brigitte over 4 years ago in reply to Brigitte

TI__Guru 65170 points

Hello Nicolas,

As I do not hear back from you, I expect that you have been able to solve your issue. If this is not the case, please post below or create a new thread if this one is already locked.

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LMR62421: circuit breakdown