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ADUM3221 Feasibility to drive load

Hi, Everyone.

I'm trying to use ADUM3221 to drive mosfet as below.

Two questions :

Q1. Can ADUM3221 drive MOSFETs as attached?(BTS5200, IRF7341)

Q2. Continuous Current value? (IF VIA is  always high, how much current can be drown on VOA)

Can It drive over 2mA?

Q3. If I want ADUM3221 to drive 1A load, Is there a limitation?

Hope to get prompt reply.

attachments.zip
  • Hello,

    Q1) The ADuM3221 is said to be a 4 A gate driver. This is referring to the approximate peak current capability, and not the constant output current. When running a MOSFET like the two in an IRF7341, the current on the VOA/VOB pins drops to near zero once the gate of the MOSFET is driven high or low. This is similar to charging and discharging a capacitor. The ADuM3221 has enough drive strength to operate an IRF7341 well.

    Q2) The abs. max for the ADuM3221 is 23 mA per pin, so 2 mA is definitely doable. If you are thinking of placing a gate pull down resistor, anything between 10 kΩ and 100 kΩ is usually a good value.

    Q3) Is the 1 A load from the power switch drain to source? If so, there shouldn't be any problem. The gatedriver will just see the gate of the device, not the 1 A going through the power MOSFET.

    The ADuM3221 provides two output channels. They are referenced to the same ground on the secondary side. If you are looking to drive two lowside switches, this part will work for you. If you are looking to operate a half-bridge, the ADuM3223 would be a better choice, as it provides two outputs that are isolated from one another.

    The ADuM3221 has a different output stage than the BTS5200 in that the ADuM3221 drives the outputs both high or low. The BTS5200 looks to have highside only on the quad outputs, meaning the part won't pull the output low, but relies on outside pull-downs. The ADuM3221 and BTS5200 are meant for different applications, but the ADuM3221 can operate the IRF7341 if that is the end goal.

    RSchnell

  • Thank you for your detailed answer.

    Have a nice day