Hi ChemE,
I never used the TPL51110 and I'm looking for alternatives to run projects using one or two AA/AAA cells, at the moment testing some "whisper nodes", but would be much happier with 40nA you're getting! As far I understand it turns the whole circuit on and off based on a adjustable timer, correct? So you always "boot" your board instead of sleeping it, losing all memory?
Another question is how does it helps with the 2xAA batteries? wouldn't the battery voltage, 2 AA gives you only 3V and not 3.3V. Also, wouldn't the voltage start to drop below an acceptable level after while?
Very interested in your results!!!