Running Atmega 2560 on 1.8V.?

Hello everybody,
Is there anyway I can run Atmega2560 on 1.8V.? I am working on a project where I am using Atmega2560 as my MCU and powering it up using single cell LI-ION battery. I don't want to use voltage Booster circuit here.

Please help.
Thanks

Not recommended; well out of spec.

ATmega2560/V datasheet

As you can see on the bottom of the fist page, You'll need an ATmega2560V running at 4 MHz or less to be able to run it at 1.8V

Is there any other Atmel chip which can help me in this situation.? and this chip should have minimum double the space of Atmega328P , 2 Hardware serials, ADC's,SPI - to interface SD card and can be RUN on 1.8V.?

Thank you

There's plenty!

The models you ate looking for is the *V models:

ATmega644PV, ATmega1284P, ATmega640V, ATmega641V, ATmega1280V, ATmega1281V, ATmega2560V, ATmega2561V.

The best option is to maybe choose a microcontroller in a DIP package for easy soldering. This leaves out all except for the ATmega644PV and ATmega1284P. These are both great microcontrollers with great Arduino support, thanks to (my very own) MightyCore.

If the ATmega1284 isn't a whole lot more expensive, you should definitely go for this one. It has 16 kB RAM, which is 8 (!!) times more than an ATmega328!

(deleted)

hansibull:
Not recommended; well out of spec.

ATmega2560/V datasheet

As you can see on the bottom of the fist page, You'll need an ATmega2560V running at 4 MHz or less to be able to run it at 1.8V

I'm planning to do a mobile project so need to run Arduino in 1.8 to 3.3V too. What need I do to let Arduino running at that voltage? Connecting an 4Mhz oscillator crystal and setting the board to 4MHz for example? Thanks

The Atmega2560V can run at that low voltage
ATmega640V/ATmega1280V/ATmega1281V: • 0 - 4MHz @ 1.8V - 5.5V, 0 - 8MHz @ 2.7V - 5.5V

The Arduino Mega uses the nonV chip and needs 4.5V no matter the speed, see the lower right graph.

Speed Grade Atmega2560 and V.jpg

How small of a board are you after? This board I offer could be assembled with a 2560V and 4 MHz crystal. Do you have a 1.8V power source?
http://www.crossroadsfencing.com/BobuinoRev17/

hansibull:
The models you ate looking for is the *V models:

Processors labeled "picoPower®" (e.g. ATmega328P) are also good choices.

I don't think there are any "rules" that says that picopower enabled devices supports 1.8v. The ATmega644P for instance support > 2.7V. If you're running it at 1.8V, you'll need the 644PV version. The ATmega1284P however works at 1.8V (According to the datasheet).

However, I don't think an SD card will function properly at 1.8v..

Pretty sure SD cards need 3.3V.