LM3697: has radiated emission to a sensor

Hi, Team

My customer is meeting  an issue that LM3697 has radiated emission to a sensor. They found the odd harmonic of 25KHz – 25K/50K/100K… And there is peak noise at 500KHz also.

could you help to provide the information on them. Thank you.

To analysis it, they want to know the clock of LM3697:

1. How does the clock generate? How many is the basic clock of oscillator?
2. How does the switching frequency generate from the basic clock of oscillator?
3. They found the radio noise changed with  input voltage. Will SW frequency change follow with input voltage? I thought the SW frequency should be constant regardless VIN.