Question About Running at 1.8v vs 3.3v [ATSAMD21J18A/ATSAME54P20A]

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I know that for some AVR chips, running at 1.8v vs 3.3v or higher meant sacrificing cpu frequency. I can't find anything about this in the ATSAME54P20A's datasheet or the ATSAMD21J18A's datasheet. Does it just not matter for arm cores? What are the tradeoffs for running at a lower voltage than the usual 3.3v?

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im a penguin

Last Edited: Wed. Feb 12, 2020 - 04:29 AM
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The SAMD21 can operate at any frequency with input voltages between 1.62V to 3.63V.  As for the SAME54 I cannot tell you, I have not looked at the datasheet.  

Look in 8.2.1 "Power Supplies" on page 36.  VDDIO powers the internal 8MHz oscillator (OSC8M) and an external oscillator (XOSC).  VDDIN powers an internal regulator which supplies DFLL48M and FDLL96M high frequency clock sources.  VDDANA powers all the other clocks including the external 32kHz oscillator.  The valid supply voltage ranges from 1.62V to 3.63V.  

 

Here is a link to the SAMD21 datasheet.

http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D21_DA1_Family_Data%20Sheet_DS40001882E.pdf

 

Finding the right information in a datasheet over 1000 pages long can be a real pain sometimes.  

 - biobuilder

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Thanks for the response. I saw this, but I didn't know if the mcu was particular about operating voltage vs operating frequency. Guess not. 

im a penguin