Problems with LT8330 12V to 15V design

Oscilloscope screen showing the behavior of the Vout

Hi 

Can you try adding 4.7pf across R1?

If that does not work please take SW node  wave forms with the conditions described 

Regards

Hi Mikee, 

thanks for your reply.

We made the test using the cap across R1, but with no improvements.

These are the measurements:

-Voltage output:

--Reg Output in DC_Coupling:

--Reg output in AC_Coupling:

-SW node:

  -SW node in DC coupling:

  -SW node in AC coupling: 

The SW node waveforms indicate that the internal switch is not fully turned on.

What's the INTVcc pin voltage?

Also, the suggested layout:

Sorry for my delayed answer,  we had some problems in equipment availability (you'll notice the old school oscilloscope we used for this measurement -  )

This is the measurement of the INTVcc pin:

Please double check whether the components are installed properly, for example, the input inductor.

Solved! The problem indeed was at the input inductor. It has been mounted 90º rotated, becoming a short circuit. Thank a lot!

Solved! The problem indeed was at the input inductor. It has been mounted 90º rotated, becoming a short circuit. Thank a lot!