Using a Mosfet

Hi,

I am aiming to make the circuit as attached. The Arduino controls a 400mA LED load that is turned on/off using a mosfet http://www.ti.com.cn/cn/lit/ds/symlink/tps1110.pdf and a single Arduino pin.

The Arduino will not be powered down, it will always put to sleep when not required.

Will this circuit work fine?
When the Arduino is put to sleep, can it keep the Mosfet load switched off when the Arduino is sleeping?

Greatly appreciate any assistance.
Jeffro

mosfet.png

A 10k from gate to source would be a start...

Thanks for your response.

A 10k from gate to source would be a start...

How does this look?

Thanks

mosfet.png

When Arduino goes into sleep mode, output pins remain at the level they were.
TPS1110 is an obsolete device.
http://www.mouser.com/Search/Refine.aspx?Keyword=tps1110
Where are you getting them?

Jeffro_Aus:
Thanks for your response.

A 10k from gate to source would be a start...

How does this look?

Thanks

Yes. Then the MOSFET will default to off when the system powers up or is reset.

Thanks for your responses.

TPS1110 is an obsolete device.

The last time i checked, they were available. I am now looking at a new version from Texas,

Is this one ok?

Then the MOSFET will default to off when the system powers up or is reset.

To confirm, the load will be off when the Arduino is powered up or reset due to the 10k resistor, and will hold its outpin state whilst sleeping?

Thanks a lot for your help

What is this setup? Eg powering down the processor does not power down the usb to tty (atmega8u2) or other components, your battery discharges faster than the power the processor consumes...

Wow, can't you find anything smaller to use? Talk about extremes.

How much current are you planning on putting thru that?
You may need to provide for cooling at Rds = 0.08 ohm (see Fig 7).

Yes, resistor holds Gate off until sketch kicks in. Output holds state while in sleep mode.

What is this setup?

I'm making a standalone Arduino project where the Arduino is sleeping when not required, otherwise it is awake. One of the Arduino pins controls a LED array of 400mA. The board is powered by a 3.7V lipo. The attached circuit shows how i will hopefully control the LED part.

mosfet.PNG

Wow, can't you find anything smaller to use? Talk about extremes.
How much current are you planning on putting thru that?

I'm planning to have max. load of 500mA. Is something like this more suitable?CSD25202W15 data sheet, product information and support | TI.com

If you can handle soldering the microscopic stuff, go for.
I can't see well enough to do stuff that small.
At least the first part had a workable form factor.

Thanks for your responses. This is actually part of a larger project that I will eventually get developed in a PCB. I will go with the last mosfet I mentioned and hopefully everything is ok.