I decided to test my LMR14206 based DC/DC again and replaced the 15uH inductor with a 47uH inductor on the 12V design. The scope pictures was a shock:
This first scope picture show what I saw as 12V out. It is 12.2V, but look at that ripple picture of several voltages. To compare I scoped what I got out of my PSU and what a shock – I saw the same signature in and huge spikes & ripples out of the DPS5005 based PSU.
This is with no load and it show the same noise signature. The Scope above have different time scaling. Replacing the DPS5005 with the older Thaoxin I also instantly saw a different ripple signal from LMR14206 as can be seen below:
This is a bit better as we have 12.2V and +/-100mV ripple out. But, I need to go back and open my DPS5005 to figure out where the ripple noise is introduced.