Hi,
If you want a cleaner outupt, I would suggest the following:
The FB node is within the switching current loop; that should be avoided. Noise on the FB affects the jitter, increasing the inductor peak current.
Also, as a general rule, minimize the switching node (U2-2) and minimize the current loops. For a buck reg, the input cap current loop is more critical (rectangular) than the output current loop (triangular).
- put C2 below L1
- rotate C1 and C2 anti-clockwise and place them so that their GND pads are as close as possible
- connect D1-anode to C1-GND with as short wire as possible
- preferably, connect C1, C2, U2, D1 GND only at C2 (on the "quiet" side). If U2 needs cooling, provide a separate heat spread plane connected to tab
- keep trace C1+ to U2-1 as close to the switch node and D1 as possible (minimize current loop)
- connect R2 at C2+ (the point you want to regulate) (not at L1 where you have added switching noise)
If you have the time, do more than one layout and compare the results. You can learn a lot from that.
BR,
Carl