The design still contains R3, for LC filter stability, which might be removed for the final version, if proven to be unnecessary.

 

I managed to assemble it by hand with a hot air solder gun and solder paste. I only had to resolder the IC once, too much paste. And it functions! I just need to do some extensive tests to measure the exact performance.

 

I added some test results in a zip file, I tested it with resistive loads, 4.7Ω, 20Ω and 470Ω. (Uncooled!) And I varied the input voltages to see what the effect is on the efficiency, as that is the major issue with linear regulators.

 

I updated the Excel sheet with some measurents I did in the lab on an 7805. (Cooled!) I put the efficiencies together in the graphs so the difference in efficiency is obvious to see. It is also interresting to take a look at the ouput voltages, the 7805 has a way higher dropout voltage.

 

I did a pulsed load test to see what would happen in an unideal load condition. I attached a 47Ω load and in parrallel a 6.8Ω load switched by an IRF530 N-MOSFET at 50kHz. That is a load step from about 10% to 85%. I am very pleased with the scope images I added here. No instability whatsoever but there is a spike when the load drops from 85% to 10%, but look at the scale, that is a frequency in the MHz range. A ferrite bead in series with the output could easily fix this. But then again, this is no realistic load scenario. I did have 1uF electrolitic caps on the input and output. A small value ceramic cap could be benificial as well.