Rooting around in the fascinating stuff at the bottom of a draw labelled 'Engineering - Junk Miscellaneous'. Delving amongst the delightful...
An Engineer in Wonderland – An 0.7V microcontroller
Last year around this time, Silicon Labs introduced C8051F9xx – a microcontroller family capable of operation down to 0.9V, and up to 3.6V.
The core does not actually run at 0.9V, there is an in-built boost converter.
Atmel has gone one better, or maybe just 0.2 better, and come up with an MPU that works down to 0.7V.
Dubbed ATtiny43U , it is guaranteed to start from 1.35V (typically 1.2V).
With its little dc-dc converter fed from 1.2V, but the processor shut down, the chip will sit there consuming only 5[micro]A – which is commendably little.
Fire the core up at 4MHz, and this increases to 5mA – also pretty good.
And the dc-dc delivers at least 17mA at 3V from 0.7V – and up to 60mA with a generous input – so there is enough to at least drive an led.
Efficiency is generally above 70%, and up to 95%, and there are a couple of firmware links so the core can control the dc-dc converter.
For operation above 1.8V, the converter can be turned off completely.
Power-down consumption is than 150nA from 3V, or 400uA running at 1MHz.
I do quite like the ability to run from a single NiMH or alkaline cell, particularly when sleep at a few uA is still possible.
Operation from 0.9V is a good idea. I am not sure there is too much to be gained from improving this to 0.7V – except a few more minutes operation from an alkaline perhaps.
But if it comes for free, let’s have that as well, particularly as the core is Atmel’s programmer-friendly AVR.
Comment below, or to firstname.lastname@example.orgTags: dc dc converter, microcontroller family, nimh, programmer, silicon labs