Discovered some issues with the main PCB’s schematic when I was checking it before making the BOM

• First issue was that the inductor I chose for the battery charge IC (BQ25792) that also makes the 9, 12, 15 and 20V for USB PD had a current rating too little (guess that’s what happens if you design a PCB like this very inexperienced like I was 8 months ago) which would have limited it to around 30W output max, so this time I calculated the required rating myself (previously got the inductor from a reference design). Found that it should have been almost double the previous 7A for the 45W I initially aimed for, but if the IC can handle 60W then why not choose an inductor for 60W? So that’s what I did, the new inductor that has a rating of 15.8A should be able handle 60W.

• Second was that for some reason I tied the SDRV pin of the battery charge IC to the battery when instead it should have been tied to GND through a 1nf capacitor if not in use. I don’t know why I did it because the datasheet clearly says “Connect a 0402 / 50V / 1nF ceramic capacitor from SDRV to GND when the ship FET is not used.” This may have been the cause why the PCB didn’t work correctly when I made the first prototype of it around 2 months ago. I thought it was because of bad soldering, so I tried to resolder everything with a hot plate and burned bunch of my capacitors and probably some other components too.

There were some other minor issues like me choosing footprints too small for some capacitors and not using the output current monitoring of the efuse. The efuse current monitoring isn’t really an issue but it is nice to see the exact output current on the display. I probably skipped it because I couldn’t understand how it worked back then.

Thank you for reading!