I have a question regarding the ADUM5401 EMC;  I am getting a frequency from the switcher at 360MHz; any application of filters used for dampening these frequencies; without having to change the PCB layout.  IE filter circuits

I have a question regarding the ADUM5401 EMC;  I am getting a frequency from the switcher (180) at 360MHz and 540MHz; any application of filters used for dampening these frequencies; without having to change the PCB layout.  IE filter circuits

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    •  Analog Employees 
    on Apr 29, 2016 10:59 PM

    Gsear: Yes, there are techniques to reduce emissions as suggested in the datasheet:

    ADuM5401/ADuM5402/ ADuM5403/ADuM5404 devices must operate at 180 MHz to allow efficient power transfer through the small transformers. This creates high frequency currents that can propagate in circuit board ground and power planes, causing edge emissions and dipole radiation between the primary and secondary ground planes. Grounded enclosures are recommended for applications that use these devices. If grounded enclosures are not possible, follow good RF design practices in the layout of the PCB. See the AN-0971 Application Note for board layout recommendations

    There are also effective techniques in app note AN-1349 that use ferrite beads to filter the ADuM540x Viso and GNDiso pins, as well as using stitching capacitors across the GND1 and GNDiso.

    Regards, Brian

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  • 0
    •  Analog Employees 
    on Apr 29, 2016 10:59 PM

    Gsear: Yes, there are techniques to reduce emissions as suggested in the datasheet:

    ADuM5401/ADuM5402/ ADuM5403/ADuM5404 devices must operate at 180 MHz to allow efficient power transfer through the small transformers. This creates high frequency currents that can propagate in circuit board ground and power planes, causing edge emissions and dipole radiation between the primary and secondary ground planes. Grounded enclosures are recommended for applications that use these devices. If grounded enclosures are not possible, follow good RF design practices in the layout of the PCB. See the AN-0971 Application Note for board layout recommendations

    There are also effective techniques in app note AN-1349 that use ferrite beads to filter the ADuM540x Viso and GNDiso pins, as well as using stitching capacitors across the GND1 and GNDiso.

    Regards, Brian

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