LowPowerLab Forum

Hardware support => Moteino => Topic started by: BarryS on January 08, 2020, 01:09:49 PM

Title: 16MHz / 3.3V and the ATMega328p safe operating area
Post by: BarryS on January 08, 2020, 01:09:49 PM
I'm considering using Moteino in a project I am developing. I see the Moteino runs at 3.3V and 16MHz, which appears to be outside the safe operating area defined for an ATMega328p in section 28.4 (page 260) of the datasheet.

I am wondering if I misread the datasheet, or if there is a justification for this? Is it simply experience has shown it not to be a problem? Perhaps if the board isn't operated close to its temperature limit, it can operate outside of the clock limit?
Title: Re: 16MHz / 3.3V and the ATMega328p safe operating area
Post by: Felix on January 09, 2020, 09:46:57 AM
Indeed at 16mhz/3.3v the atmega328p is slightly overclocked.

This was asked many times before so I will give you the TLDR:
No problems found in practice on many projects implemented with Moteino and custom boards, deployed from underground, caves, water, space, residential, commercial, industrial, etc.

You can always dial down to 8mhz for even lower power, to be within the datasheet spec.
Title: Re: 16MHz / 3.3V and the ATMega328p safe operating area
Post by: BarryS on January 09, 2020, 12:41:13 PM
Thanks. I am not surprised the question has been asked before - but I couldn't find anything with a search. I'll give them a shot. As you say, I can always mess with the prescaler to slow them down if I find reliability issues.