Computing stuff tied to the physical world

Out of spec

In AVR, Hardware on Feb 27, 2009 at 00:01

Running an Atmega168 at 16 MHz on 3.3V power is beyond its specs:

Out of spec

Officially, you’re only allowed to run it at up 13.333 Mhz with 3.3V. Easy math: it’s 10 Mhz change over a range of 1.8V, and 3.3V is one third of the way up from 2.7V.

Yet I’ve been running this chip with a 16 Mhz resonator on at least a dozen JeeNodes now. I don’t know whether that means all is well because the limits are conservative ones, or whether they might fail outdoors in an extended temperature range, or whether a few units will not work.