• ADUM4221 testing issue


            We directly replace UCC21540 to ADUM4221 as below schematics. We remove DT pin decoupling cap. The application is server power. Bit while test, the server power will boot normally at no load. But have over 0.2A load, ADUM4221 will shutdown the…

  • ADUM4221 DT connect to 5V(VDDI)


               Customer use SI8233 on board. We will use ADUM4221 to replace it. Customer don't use DT function of SI8233 and DT pin connect to 5V(VDDI).

               Could ADUM4221/ADUM4221-1 DT pin connect to pull hign (5V) for direct replacement? Or ADUM4221…

  • RE: ADUM4221 DT Pin decoupling Cap


    The ADuM4221 cannot have any decoupling capacitance on the DT pin. It is designed to not need it, and capacitance will affect the DT operation.



  • RE: ADUM4221 DT pin connect to 5V(VDDI)

    Hello Patrick,

    It is correct that the ADuM4221-2 does not contain overlap protection. The ADuM4221-2 will allow both channels to be on at the same time if the inputs are both high.

    Overlap protection and deadtime control are very related. In an ideal…

  • RE: ADuM4221 VDD1 series 1.2KΩ resistance


    As pictured, the 1.2 kΩ resistance will be in the way of the decoupling capacitance, meaning that as the part needs more current, the 5 V supply will droop going into the ADuM4221. It is possible to put a resistor to the left of the decoupling…

  • ADUM4221 LTspice model request.


    Can`t find ADUM4221 LTspice model on product page.
    Only IBIS available.

    -- Regards,


  • RE: ADUM4221 comparison to UCC21540

    Hello Patrick,

    The ADuM4221 secondary side supports higher supply voltage as compared to the UCC21540. Also, the CMTI rating of the ADuM4221 is higher than the UCC21540.


  • About ADUM4221/ADUM4121 magnetic isolation and VDD1 power supply

    About ADUM4221/ADUM4121 magnetic isolation and VDD1 power supply

    1.ADUM4221/ADUM4121 is magnetic isolation. In PCB design, it is usually close to the main transformer. Will the transformer and the internal isolation coil of ADUM4221 interfere with each…

  • ADUM4221 DT pin with a paralleled 2.2nF

    Hi ADI Expert

    May I know if it will cause any issue if I add a 2.2nF paralleled to the DT pin resistor(around 20k for my case)?

    thank you


  • RE: ADUM4221 isolation between high side output and low side output


    The isolation between the highside and lowside is not a safety isolation barrier, and is not covered by the isolation standards. It is suggested to keep creepage distances the same as would be required in a reinforced isolation situation, but since…