# Understanding Datasheets

Discussion in 'General Electronics Discussion' started by Xenobius, Sep 12, 2017.

1. ### Xenobius

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0
May 15, 2012
Hi all,

I have a question with regards to knowing how much voltage/current I need to drive a Mosfet and transistor.

I have this Mosfet available http://www.mouser.com/ds/2/427/sq3427ee-101865.pdf
When I look at the datasheet, I'm sure there is enough information to tell me how to drive it but I want to understand more.

Could anyone first point me to how to calculate the voltage/current needed and secondly how to understand better the technical terms used?

I understand Mosfets are driven with Voltage and transistors with Current and Mosfets use Gates while Transistors use Base so the basic idea is there just not technical enough.

Thanks a lot
X

2. ### Harald KappModeratorModerator

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2,629
Nov 17, 2011
You need to understand how a MOSFET works (alternatively see here), then you will understand the datasheet, too.
There is no use in explaining datasheet terms or doing calculations when you lack the understanding.

shrtrnd and dorke like this.
3. ### BobK

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1,688
Jan 5, 2010
The gate of a MOSFET is essentially a capacitor, with the source being the other terminal. Therefore it does not draw any current when the voltage on it is steady.

Current comes into play only for fast switching times. Some will need over an Amp of current, for nanoseconds, to achieve their fastest switching capability. The total gate charge tells you how much charge the gate takes, from which you can determine the switching time for any given current.

Bob

Last edited by a moderator: Sep 12, 2017
4. ### Xenobius

125
0
May 15, 2012
I see, that makes a little more sense... thanks, I'll keep reading.

5. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
In a recent video, Dave Jones of eevblog goes through a datasheet showing you how to read it. Sure, it's not the component your interested in, but it may still be worth a look at.