LMR51430: switch regulator keeps burning out at VIN net

Hello

You may have some kind of voltage transient on your input supply.

Try to capture the input voltage when the device becomes damaged.

You may need more input capacitance in order to damp out any overvoltage

spikes on the input.

Is the device damaged during start-up, or during some other kind of test ?

Can you provide images of your PCB layout.

Thanks

Here is the PCB layout.

Hello

1. In general the components should be placed closer to the IC.

2. A ground plane flood on the top layer should be used; as well as the bottom plane.

3. Cinx, C4,C5, C6 should all be as close to the device as possible.

4. Note that the data sheet recommends 4.7uF on the input.

5. Cboot should be close to the device and connected with short wide traces.

6. The feedback components should be connected directly to the output capacitor.

7. In general some ceramic output capacitance is needed on the output, depending

 on the ESR of the aluminum output capacitor.

8. In general you will need to follow the PCB layout example in the data sheet

as closely as possible.

Thanks

I appreciate your help Frank. How about this? I added 2 x 4.7uF and 1 x 0.1uF input capacitors per the data sheet (Section 9.2.2.6).

My input will be 24v so i used 50v for each 4.7uF.

I tried to move the parts as close a possible while still allowing me space to solder the IC.

Added additional ground plane under the IC and more VIAs.

Hello

OK

I think you will also need to check that the input voltage is not

overshooting when you apply your input supply.

This could be caused by long leads from the input supply to the regulator.

Thanks