I need a 12V and 3.3V power supply for a circuit, so I designed a regulator onto a board to turn the 12V to 3.3V. I used the TI TPS62162DSGT to do this, and my schematic looks like:
I used the inductor and capacitor BKPB001608DZ2R2MA2 and GRM188R60J226MEA0D respectively along with this small test board:
I soldered up the board using low temp solder paste and a hot plate, which is less than ideal. But I expected it'd be fine for a test. Checking the components, they seem like they are soldered correctly and in place:
I checked all of the connections and found no shorts, and the capacitance is correct. Unfortunately my multi-meter won't measure inductance. I plugged it in, and it worked fine, although the voltage I measured was only 3.26V. I unplugged it and plugged it back in 2 more times, there was a pop, the device began heating, and the housing briefly caught fire. This has happened twice now, so I suspect a design failure on my part, but I've checked the datasheet and TI's "WEBENCH" numerous times, and can't pin it down. Maybe the ground or voltage side is making contact first, but it wasn't grounding through anything so far as I can tell (off the table). I feel like an idiot, but does anyone know what's happening, I can't figure it out. Thanks in advance.