About LM43601-Q1 RE(radiated Emission)Graph

Anthony,

EMI is comically termed as black magic for this very reason. The higher the frequency the harder it is to pinpoint the origin.

The data is correct and there is no easy way to determine what interaction of harmonics would result in the curve you see. We only know of ways to mitigate it in general and we apply those liberally in EMI sensitive applications.

It is important to note that once the IC is implemented in your layout, the EMI result could be different than what you see in the datasheet and there are too many factors that affect it, but the chief ones are switching frequency (higher has worse EMI) and layout (<1uF bypass caps are important and high current paths must be minimized).

Thanks,
Anston