LTC3899 noise caused by inductor

Question

Hello everyone, 
 
 I encountered a problem when working on a design for a power supply with LTC3899. At some point I started to hear a noise near the converter and from my experince it sounds like an inductor which is saturated. I have 12V as Vin for the boost and it gets 12.62V output that is used further as Vbias for this converter and one of the bucks get 10V output. 
 Do you think that the noise could come from anything else? The converter is set to work in continuous mode. 
 Kind regards!

Roadrunner19 · Accepted Answer

Thank you guys, I solved the problem. It seems that the controller was working in Burst Mode indeed and that was causing the noise. I changed the working mode to continuous operation and the noise stopped. 
 Kind regards!)

ADIApproved · Answer

You have two Channels operating near drop out. The boost and your buck. When approaching drop out the converters will drop pulses to maintain regulation. this can often cause bursts of switching to happen at audible frequencies which are then radiated as audible noise from components on the board.

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LTC3899 noise caused by inductor