I'm trying to use a Semtech 5V 3A buck regulator, and there is obviously something wrong with the circuit, because whenever I try to pull current from it, the IC catches fire...
I've done buck regulators before and the schematic looks fine to me, but maybe I'm missing something obvious. I depopulated U15 and hooked up resistors to the output to draw current, and when ~100mA were being drawn the voltage started to drop until eventually the regulator caught fire. Any thoughts on causes?
Below are the different parts with digikey part #s:
- U2: TS30013-M050QFNRCT-ND
- L2: SRN6045TA-4R7MCT-ND
- C4: 1276-1104-1-ND
- C6, C8: 1276-6504-1-ND
- C2: 1276-6736-1-nd
The full project can be found here: https://github.com/UWARG/ZeroPilot-HW/releases
EDIT: Below is a screen shot of the pcb layout. You can also look at the github link if you are familiar with KiCad.
EDIT #2: Below is an oscilloscope screenshot of the input on CH2 and output on CH1 with a 200 Ohm load (25mA). There isn't substantial noise for either signal at any frequency, no matter how much I zoomed in or out. As you can see, the output voltage has dipped to under 5V under a 25mA load.
5V_INT_OUT node with no load:
5V_INT_OUT node as it started to smoke:
Hopefully those oscilliscope images help, I managed to catch one of the screenshots half way through the buck regulator failing, using a 200mA load.