Points in general:
Look at the losses in the inductor. You may have a higher voltage drop across it because of too thin conductors. Make sure you have thick enough wires to carry the current that will eliminate voltage drops.
Also switching losses in the diode will be a factor. Make sure diode is fast enough and have the required reverse blocking voltage rating. Sloppy wiring or layout can produce unwanted leakage inductance that together with fast switching currents will produce high voltage spikes.
Layout is very important, short wires with star type ground connections.
Avoid large enclosed loops for currents from output, to load, and back to ground. Keep this areas as small as possible.
Hope it helps!
E
I see that on the maxim site they have a good amount of tips. It is worth reading....here is the section about layout.
From maxim site:
Layout
Component selection is very important in controlling EMI, but the circuit-board layout and interconnects are equally important. Especially for the high-density, multilayer circuit boards often used in switching power supplies, layout and component placement are critical to the circuit's proper operation and interaction. The power switching can cause large dv/dt and di/dt signals in the circuit-board traces, which lead to compatibility problems by coupling to other traces. Compatibility problems and expensive circuit-board revisions can be avoided, however, by taking extra care in the layout of critical paths.
A distinction can be made between radiated and conducted emissions in a system, but the distinction blurs when talking about interference in a circuit board and wiring. Adjacent traces that couple electric fields also conduct currents by means of parasitic capacitance. Likewise, traces that are coupled by magnetic fields act somewhat like transformers. These interactions can be described in terms of lumped components or through field theory. Which approach to take depends on which method more accurately describes the interaction....
**broken link removed**