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LT3032 oscillating

Hi everyone,

I am trying to implement the LT3032 voltage regulator for the small footprint and low noise. However, in my current design I have the problem that the positive rail is oscillating with a frequency dependent on load current (a few kHz).

The circuit seems to get more stable if I remove the bypass cap on BYPP, but as I mentioned, we want to keep the noise low.

Interestingly the simulation using LTSpice shows the same large scale sawtooth oscillations I'm seeing on my board. I tried changing the input/output caps to higher value/higher ESR ones, but that didn't help either. The negative rail is not affected by all of this. All caps are X7R/X5R.

I attached the simulation file I'm using. 6076.3032.zip

Is there anything I missed from the datasheet?

Thanks for your help!



smaller screenshot
[edited by: LeChuck at 8:35 AM (GMT -4) on 23 Oct 2018]