Advice on what MOSFET to use?

Back again. I got my Arduino to drive a RGB LED strip with these MOSFETs but now I am trying to drive them with a 3.3volt output. I am running into issues and I am guessing that is because the 3.3v is not enough to switch these MOSFETs (is that correct??).

Could anyone point me towards some options for appropriate MOSFETs for this task assuming a max amperage ~ 5 amps?

Thanks

http://aosmd.com/res/data_sheets/AON2400.pdf
http://www.digikey.com/product-detail/en/alpha-omega-semiconductor-inc/AON2400/785-1422-1-ND/3594492
Might be a little awkward to wire up.

CrossRoads:
http://aosmd.com/res/data_sheets/AON2400.pdf
http://www.digikey.com/product-detail/en/alpha-omega-semiconductor-inc/AON2400/785-1422-1-ND/3594492
Might be a little awkward to wire up.

This one is a slightly easier form factor to work with:

DMG6968U-7 Datasheet
DigiKey Link

Description:
MOSFET N-CH 20V 6.5A SOT-23
N-Channel 20V 6.5A (Ta) 1.3W (Ta) Surface Mount SOT-23-3
25mΩ @ VGS = 4.5V
29mΩ @ VGS = 2.5V
36mΩ @ VGS = 1.8V

SOT-23 is a lot easier to hand solder..... :slight_smile:

Thanks for the replies! I went with one similar to the adafruit recommended IRLB8721 with some help from the digikey online chat. Thankfully digikey is only a few hours away so lets hope for quick and affordable shipping lol

bmoe24x:
Back again. I got my Arduino to drive a RGB LED strip with these MOSFETs but now I am trying to drive them with a 3.3volt output. I am running into issues and I am guessing that is because the 3.3v is not enough to switch these MOSFETs (is that correct??).

Could anyone point me towards some options for appropriate MOSFETs for this task assuming a max amperage ~ 5 amps?

Thanks

Those MOSFETs are rated for 10V, they are not even remotely logic level, let alone 3.3V logic compatible.

MarkT:
Those MOSFETs are rated for 10V, they are not even remotely logic level, let alone 3.3V logic compatible.

I see that now. Went with them on a suggestion from elsewhere. At this point I am surprised they worked with my actual Arduino. Any advice on what to look for in the future regarding what to look for based on a certain voltage I have to drive them?

  • Look for this graph in the data sheet, you want a low Vgs for the Id current you are designing for.
  • Look for low Rds(on) resistance for the Vgs voltage used.

.

LarryD:

  • Look for this graph in the data sheet, you want a low Vgs for the Id current you are designing for.
  • Look for low Rds(on) resistance for the Vgs voltage used.

.

Thank you!

See these links:

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bmoe24x:
I see that now. Went with them on a suggestion from elsewhere. At this point I am surprised they worked with my actual Arduino. Any advice on what to look for in the future regarding what to look for based on a certain voltage I have to drive them?

Rds(on) is quoted at one or more values of Vgs - the gate-source voltage guaranteed to turn the device on
to a particular on-resistance. That's the first thing to check. Typically for logic level the value of Vgs is 4.5V
(5V allowing for voltage drops in the wiring and manufacturing spread of the voltage regulator). 10V is normally
quoted for high power MOSFETs designed to work from 12V supply - this allows for voltage drop in a car battery,
for instance.

MarkT:
Rds(on) is quoted at one or more values of Vgs - the gate-source voltage guaranteed to turn the device on
to a particular on-resistance. That's the first thing to check. Typically for logic level the value of Vgs is 4.5V
(5V allowing for voltage drops in the wiring and manufacturing spread of the voltage regulator). 10V is normally
quoted for high power MOSFETs designed to work from 12V supply - this allows for voltage drop in a car battery,
for instance.

Thanks for your response. I am new to mixing software with hardware but excited to get my project completed. Watched a very helpful video on YouTube about mosfets that clarified a lot.