Hello,
I have used the tps61200 (switching boost regulator) on a couple of recent designs. While debugging the other day, I touched the circuit board around the regulator with my thumb and noticed a small voltage lag on the output. Being curious, I started lightly touching around the regulator and external components (voltage divider, input/output caps). I started seeing wild output voltage swings. I then lightly breathed on that area of the PCB and saw the output voltage drop from its nominal 3.62 volts down to 1.7 volts!! If I breathed on it long enough I noticed the output voltage would stay lagged longer and longer (30 seconds to 60 seconds). My question perhaps belongs in a different forum, but I was curious if this behavior is caused by somehow changing the impedance of external circuitry by introducing humidity? Is this a switching type regulator specific issue? My PCB board will be exposed to occasionally 80% + relative humidity conditions. Is there a good protective coating for PCBs that you could recommend that would protect against this presumable humidity issue?
P.S. The tps61200 is working excellent without the above mentioned scenarios.
Thank you!
Jason
