Continue to Site

# Query on MOSFET

#### FreshmanNewbie

##### Full Member level 6
There's this MOSFET (https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/414/SH8K5.pdf)

The gate threshold range for this MOSFET is given as 1V to 2.5V from the table (but from the table I see this value is for a drain current of only 1mA).

My question is, I want to get a drive current of 1A. In that case, What should be the maximum allowable gate-source threshold voltage I can give?

Seeing the graph below, Gate-Source voltage vs Drain current, the maximum gate-source voltage that is shown is 3V.

So my question is:

1. What is the maximum gate-source voltage that I can give to get a drain current of 1A?

2. What if I give 10V as gate-source voltage? - I know that I won't damage the MOSFET as the maximum gate-source voltage that is mentioned in the datasheet is 20V. So, what would happen if I give 10V as Vgs?

Step back and declare whether your "1A" is a
-controlled- 1A with tolerance and load resistance
rejection, or -at least- 1A with negligible loss in the
switch.

If I had to guess I'd say the latter. And that everything
to the right of Vgs=3 is just "more of the same" (until
you rupture the gate ox). But guessing is not a good
use of peoples' time.

There's this MOSFET (https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/414/SH8K5.pdf)

The gate threshold range for this MOSFET is given as 1V to 2.5V from the table (but from the table I see this value is for a drain current of only 1mA).

My question is, I want to get a drive current of 1A. In that case, What should be the maximum allowable gate-source threshold voltage I can give?

Seeing the graph below, Gate-Source voltage vs Drain current, the maximum gate-source voltage that is shown is 3V.

So my question is:

1. What is the maximum gate-source voltage that I can give to get a drain current of 1A?

2. What if I give 10V as gate-source voltage? - I know that I won't damage the MOSFET as the maximum gate-source voltage that is mentioned in the datasheet is 20V. So, what would happen if I give 10V as Vgs?
great, big RTFM for you. There’s a plot of drain current vs Vgs. There’s another plot of Rds vs Vgs. What more do you need????

The data sheet tells all.

If you are using it as a switch, this shows that the minimum Vgs on voltage should be 4V:

This shows the maximum Vgs you can apply without damage:

FvM