Hi,
Under idle conditions, the circuit outputs 11.5V, when putting on a 12V fan rated for 0.1A, output goes down to 10V. Other loads similar drag the output down.
I am using a 16V input. There are two variations from the webbench design.
1) I am using a differently branded 8.2uH inductor, but it is rated similarly (tolerance, series resistance, saturation current, current rating, etc) to the TI recommended part.
2) feedback is using a 10K ohm and 750ish ohm resistor, but this should only have a minor effect on the setpoint.
Neither of these explains the behavior of the circuit.
I have fabricated two test boards, both of which exhibit the same behavior. On one of them, I also tried a different webbench-calculated compensation network of 31.6k ohm resistor, 1nf, and 1pf, which did not fix the problem either.
Schematics and layout attached. Thanks :)