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SAM3N00B repeatedly powers up and down..is this OK?


Well-Known Member

We are using a SAM3N00B microcontroller in our "special" emergency light application.

Whenever the battery is removed when the mains is ON, the microcontroller repeatedly powers down and powers back up again.......(once every 5 seconds)

Is this a problem? (does repeated power up and down damage the micro?)

Our new software engineer says it is a problem, but can't say why.

Its certainly not a problem from the point of view of the operation of the unit.

SAM3N00B datasheet


Well-Known Member
Powering up and down of a microcontroller doesn't damage it. It is important to take the rest of the circuit into account, as it is possible for things that the microcontroller is connected to cause issue to themselves or to the microcontroller. This is not normally an issue if the hardware engineer has put in the appropriate fail-safes for when e.g. the microcontroller pins are at undefined states.

Your new software guy should provide a reason for his opinion, otherwise it's as good as baseless superstition.


As dougy83 says it depends on the circuit. On switch off things could be left in an undefined state if the code doesn't have a warning to power stuff down. Also you need a reliable power up sequence for the hardware and the software. But you should do these things as a matter of good design, as power interruptions can occur when least anticipated.

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