I'm designing a circuit to control power going to a heater. I'll be using this n-channel mosfet. My intended voltage values are:

1 is at 24 VDC for both circuits.

I want the mosfet to be on when 3 = 3.3V and off when 3 = 0 V.

I'm still pretty new to mosfets and want to make sure this will work before ordering the parts. Any help is appreciated. Thanks.

Circuit diagram

  • 3
    \$\begingroup\$ You need p-mosfet or place that n-mosfet to low side. \$\endgroup\$ Feb 21 at 16:42
  • \$\begingroup\$ that won't work until you swap the heater and fets in the diagram. In fact, that could blow the FETs as (24v - 3.3v) > 20V max VGS in the datasheet. \$\endgroup\$
    – dandavis
    Feb 21 at 17:55
  • \$\begingroup\$ I see, I switch the mosfets and the heater so the source is connected to ground. So then when I apply 3.3V to the gate, Vgth will be 3.3V and turn on. Then when I put 0V to the gate the Vgth will be 0V and it'll turn off? Is that right? \$\endgroup\$
    – Smashley
    Feb 21 at 19:45
  • \$\begingroup\$ Wrong. It's supposed to be Vgs, not Vgth. So voltage between gate and source. \$\endgroup\$ Feb 22 at 8:25

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