ADuM4160 internal modulation frequency

Hello,

I'd like to know what is the frequency of the internal modulator of ADuM4160?

I'm seeing a 107Mhz EMI peak emitting from a board and I would like to investigate if it is possible it is coming from ADuM4160, thank you.

Regards.

  • Hello Samba-guy

    The ADuM4160 uses a pulse based data transfer scheme, as opposed to an On Off Keying of a carrier.  We send 1 pulse for a 1-0 transition and 2 pulses for a 0-1 transition, so there is no carrier.

    108MHz is a harmonic of the USB high speed data 9x12, so it is possible that common mode leakage is stimulating a resonance in your CB.  As an experiment I would suggest treating the barrier as a patch antenna, and see if adding capacitance across the barrier could suppress the resonance. If that works, you could explore layouts that could kill the resonance.

    Let me know your progress,

    Best regards

    MSCantrell