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ADuM4221 VDD1 series 1.2KΩ resistance


ADuM4221 VDD1 VIN: Can a 1.2KΩ resistor be connected in series with 5V? 

Thank you~

  • Hello,

    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 capacitor. In that way, the decoupling capacitor can fill up and provide a solid DC value to the ADuM4221. I recommend not going above 100 Ω, as 1.2 kΩ may reduce the available current into the part creating voltage drop across the resistor. We expect the VDD1 pin to take in up to 10 mA during normal operation.