I’m blocked because execution credits are unavailable, so I can’t add parts, wire the schematic, run calculations, or validate the design in the project right now.
Your requirement is clear: design a PCB power supply with 20–30 V input and 12 V output at 10 A. This is a 120 W buck converter, so the design should use a high-current synchronous step-down regulator/controller, not a simple linear regulator. Key remaining work:
Select a buck controller/regulator rated for at least 30 V input and 10 A output, preferably with margin.
Calculate the power budget and thermal losses.
Choose inductor, MOSFETs or power module, input/output capacitors, feedback resistors, current sense components, and protection.
Add input protection: fuse, TVS diode, reverse-polarity protection if needed.
Add output protection and test points.
Create the schematic from the datasheet-recommended application circuit.
Run electrical review and simulation where possible.
Proceed to PCB layout with careful high-current routing, wide copper pours, thermal vias, and short switching loops.
When credits are available again, I can build this as a complete schematic first, then ask for confirmation before moving to PCB layout.