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ADuM5230 with noisy isoGND

Hi,

I am trying to use ADuM5230 to function as an AC switch in my resonant converter design.

The floating ground between two MOSFETs (with back-to-back configuration, having their source as common reference point) is connected to GNDiso, however, with a lot of noises as shown in the attached file.

Would ADuM5230 be able to operate in such a condition?

Kind regards,

William

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  • William: Looking at your results, which look like simulations, I see about a 5MHz ringing and about a 15V/100ns dV/dt on the ISOGND - is this with respect to GND1? This amount of dV/dt should not be a problem for the ADuM5230 according to the 25kV/us specification for CMTI. Also, you can look at the curves in the datasheet section on Commom Mode Transient Immunity and see that even sinusoidal tranients at 5MHz will not be problem for the ADuM5230 at a 15V/100ns rate.

    This assumes you have very good bypassing with 0.1uF ceramic capacitors very close (2mm not 20mm said in datasheet) to the VDD1 to GND1 pins and the VISO to GNDISO pins together with a 1uF or 10uF bulk capacitor.

    Regards, Brian

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  • William: Looking at your results, which look like simulations, I see about a 5MHz ringing and about a 15V/100ns dV/dt on the ISOGND - is this with respect to GND1? This amount of dV/dt should not be a problem for the ADuM5230 according to the 25kV/us specification for CMTI. Also, you can look at the curves in the datasheet section on Commom Mode Transient Immunity and see that even sinusoidal tranients at 5MHz will not be problem for the ADuM5230 at a 15V/100ns rate.

    This assumes you have very good bypassing with 0.1uF ceramic capacitors very close (2mm not 20mm said in datasheet) to the VDD1 to GND1 pins and the VISO to GNDISO pins together with a 1uF or 10uF bulk capacitor.

    Regards, Brian

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