Why two mosfets in circuit for "N-MOSFET driver"

[christoffert]

Hi, I have been trying to wrap my head around why two mosfets are necessary in the circuit for the Addressable N-Mosfet Driver and not just one? What are the differences between the two and what is the meaning behind connecting them in that way?

Circuit: https://cdn.shopify.com/s/files/1/0045/ ... 1977644917

Mosfet 1 - RJU003N03 Datasheet: https://media.digikey.com/pdf/data%20sh ... 003n03.pdf
Mosfet 2 - NTD5867NL Datasheet: https://www.onsemi.com/pub/Collateral/NTD5867NL-D.PDF

Thanks a lot.

Cheers
Christoffer

[Officialuser]

I thought the first one had a smaller drive threshhold requirement, but it doesn't seem to. I am at a loss as well.

[ilium007]

I came here to ask the same question ! I can't understand why the RJU003N03 is being used, the NTD5867NLT4G N MOSFET can easily be driven by logic level input.

Did anyone get an answer on why the smaller MOSFET is being used ?

[Brissieboy]

Just a suggestion, but maybe because the WS2811 is a current driver device it cannot be guaranteed to reach appropriate logic levels to fully drive the NTD5867.
You could try an email to support@freetronics.com.au and see if they have design details.