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Choose the right Mosfet

aaronik19

Sep 4, 2017
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Sep 4, 2017
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Dear Friends,

I would like to choose a N-Channel Mosfet which needs to be triggered by 5V signal to switch on, and 0V to turn off. The amount of current needed is about 2A from Source to drain (to drive the load). Am I right to say that on datasheets I need to look for the VGS to be able to drive from 5V microcontroller?

Thanks
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Look for a MOSFET described as "logic level"

You probably should be looking for something which is rated for a continuous Ids of 4A or more.
 

BobK

Jan 5, 2010
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And don't be fooled by the gate threshold voltage. That voltage is what it takes for the MOSFET to pass 250μA, it will not turn the MOSFET on for a 2A load. The threshold voltage is more of an indicator of what voltage will turn the MOSFET off completely.

Bob
 

Awesome Academy

Sep 6, 2017
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Sep 6, 2017
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There are two relevant datasheet parameters here. The first you are looking for is Vgs(th). It needs to be significantly below 5V. But even better than this, look for information on Rds(on) at different values of Vgs. If you get for example Rds(on) of 50mR at Vgs=4.5V then heat generated in the FET would be a very reasonable 2*2*0.05=0.2W.
 
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