Micro's current draw goes up when its Vdd rail goes near the threshold...why?

[treez]

Hello,

We are using the Atmel SAM3N00B micro.
We set the supply monitor to 3V.
Why is it that when the micro's supply rail gets near 3V its current draw goes up by 3mA (from 1mA to 4mA)?

SAM3N00B MICROCONTROLLER DATASHEET:
http://www.atmel.com/Images/doc11011.pdf

 

[barry]

When you are below the threshold, the device is asleep, isn't it? I think that's the whole point of the supply monitor, to shut the chip down when the power falls. Obviously, it draws more current when it's running than when it's asleep.

 

[treez]

ok but the current peaks up as it falls to the supply threshold, then goes back down again as the supply rail falls further