2 layers22.7 × 29.5 mm

BuckConverter
Roy1112/PCB-Layout-and-Component-Selection-of-a-Buck-Converter-in-KiCad
12V car battery to 5V,3A USB-C out
16 parts
Boards in 1 GitHub repository, designed in KiCad, that use the RMEF0603FT10K0 by Stackpole Electronics (SEI) (-55℃~+155℃ 100mW 10kΩ Thick Film Resistor ±1% ±100ppm/℃ 0603 Chip Resistor - Surface Mount ROHS). See how each wires it, with its parts, size, README and files; the RMEF0603FT10K0’s symbol, footprint and pinout are on its own page.

Roy1112/PCB-Layout-and-Component-Selection-of-a-Buck-Converter-in-KiCad
12V car battery to 5V,3A USB-C out