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 other?

2.The maximum power supply VDD1 of ADUM4221/ADUM4121 is only 6.5V. When cooperating with UCC256304 PWM IC, it is necessary to add an LDO for ADUM4221 separately to supply power. Besides this solution, is there any better solution?

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    •  Analog Employees 
    on Aug 7, 2020 1:14 AM


    1. The ADuM4221 have excellent immunity against magnetic fields. The coils themselves are very small, so coupling from external sources requires extremely larger magnetic fields if it were to be able to produce a signal on the coils. I don't envision any problems with the parts being next to transformers.

    2. Yes, some kind of voltage regulation would be required to reduce the VDD1 supply for the ADuM4221 and ADuM4121. 6.5 V is the abs. max, so it is recommended to operate below that. A 5 V supply does is a good supply to design for.