Mosfet BSR802N suitability ...for UNO

I am planning to use this N-Channel MOSFET for being switched ON/OFF by a Port Pin of the UNO. The load on the MOSFET is the UNO itself - so all together may not exceed 100 to 200mA.

the data sheet is here : http://www.farnell.com/datasheets/1648230.pdf?_ga=1.67044590.1144235018.1483419470

The MOSFET will be used in a kind of Push to ON latch application running off a 3.7V Lithium Ion cell.

The user pushes a key which fires the Gate of the MOSFET. The MOSFET in turn powers the UNO which then holds the gate at about 3.5V via a digital pin for about 10 seconds. The UNO does what it is supposed to do and then after 10 secs, the port pin drops to LOW switching off the MOSFET.

Will the MOSFET suit this requirement ?

The transistor will work at low logic levels. Draw and attach the schematic for us to see.

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SO here is the sketch…

UNO with MOSFET.jpg

Make sure that the (un-drawn) signal lines from the Arduino to the RF module are either set to HIGH or as INPUTs before powering down the module using a low-side-switch like this, because in the powered down state the whole RF module is sitting at Vcc.

Most of the time high-side switches are used for powering peripheral devices because ground can remain commoned up.

MarkT: .....

Most of the time high-side switches are used for powering peripheral devices because ground can remain commoned up.

Good point. But then it means I need to use a P-Channel MOSFET and the Gate has to be at "0" Volts for the MOSFET to fire. Not very comfortable doing this.

I am actually now finalizing on the FQP30N06L ... just a query on this :

Vgs Threshold is at 2.5V RD(s) ON test Voltage Vgs is 10V

And at best my UNO can drive the gate at about 4.5V. This means I will never be able to get the quoted Rds(on) value of 0.027 Ohm ? Not that I need it anyway as my load is pretty small - but just curious.

Thanks