Thanks for looking into my question.
I have a circuit that uses 2 LTC3633 to generate 1.0v, 1.2v, 1.8v and 3.3v. Both LTC3633s' switching frequency is set at 4MHz. The voltage output seems ok, but the switching frequency of 1.0v, 1.2v and 1.8v seems to be unstable. The waveform of 3.3v is rather clear and sharp:
But the waveforms of others seems to be quit fuzzy:
My schematic is as follow:
I am wondering whether this issue is important. If so, how can I solve it?