Hello everyone,
I am working on a project that needs to be extremely small and last at least 14 hours between charges.
Input is a single cell Li-Ion battery rated as 3.7V 2,000mAh.
Output needs to be:
5v - 200mA (max), 500uA (sleep)
3v3 - 116mA (max), 2.4uA (sleep)
The device will sleep most of the time.
Waking only the MCU (9mA) and Bluetooth 4 Low Energy module (27mA) every 8 seconds (for about 1 second).
And waking everything else only if user input is provided (sleeping again after 10 seconds of no activity).
My question is, what is recommended to get the required voltages at the required current?
Should I:
- Step-up the 3.7V to 5V then down to 3.3V?
- Step-down the 3.7V to 3.3V then up to 5V?
What configuration / components should I use to get maximum efficiency and not waste current?
I appreciate any help I can get.
Thanks,
Anthony
Australia (not Austria)