High-power LEDs and drivers board

I was asked to design a board with four 3W LEDs, integrated constant-current drivers, thermal compensation (to throttle current to prevent heating past a certain safe temperature), and dimming via an external potentiomer.

I designed the schematic and bill of materials by consulting the LED emitter datasheets and application notes, driver datasheets, and an application note for EMC compliance in an automotive environment. I could find no example of a driver that uses both thermal compensation (or thermal foldback) and analog dimming, so I improvised this circuit myself.

I laid out the PCB in Eagle and produced Gerber files. My first prototype came from Iteadstudio in China. It was done well but took 3 weeks to arrive. It cost only about $10 for 10 copies, plus shipping.

After some revisions, I had my second PCB made by "Beta Layout" in Germany. The service was super fast (they even offer an option for one-day service), they sent me photos of each stage of fabrication, the quality was good, and the price was not bad. (Beware their website; you have to re-enter some data after any change, and you need to re-attach your file(s) at the end. They'll accept either Gerbers or Eagle .brd file.)

I had trouble seeing the smallest (0603) parts using the magnifiers we have at XC. I suggest using a jeweler's binocular magnifying glasses (face-mounted, like glasses, e.g. this) for this work, if you don't have access to a binocular microscope. The latter is standard for PCB assembly.

I had a prototype assembled by a local contract manufacturer, Mastek-Innerstep. They did a good job for a reasonable price.

Update 6/13/2023: The client encouraged me to publish this to Github at https://github.com/LiamDGray/LightBoard2x2 . It's under a CC BY-SA-3.0 open-source license.