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SPBT2632 (C2A) for ultra low power consumption - Tips and strategy?

Question asked by debelle.adrien on May 24, 2016
Hello everybody,

I am designing a small stimulator that needs to wirelessly communicate, for research purposes, and I use the SPBT2632C2A for its low power capabilities and small size. There is a battery embedded but I want it to be as small as possible (for now 90mAh) and to last few weeks.

My strategy is the following:
I only need few exchange of data every 5 minutes, thus I use a power switch to remove the supply voltage from the device, and I switch it ON only when needed. But it leads to high current consumption during stratup (~30mA_rms during 2s) and then high current consumption during the sppconnect phase (~20mA_rms during 2.5s). Starting up the device every 5 minutes is still far better than keeping the device supplied all of the time (even with the LPO design that I use as advised in the datasheet for low power) because I measured the sleep mode current and it is far from consumming only 70µA as mentionned in the datasheet.

- Would it be some parameters refinement (I already put the sniff, shallow sleep, CPU clock at 2MHz,etc...) to make the device consume less or react faster? During startup and SPPconnect?
- Would you advice other powering strategies to improve the overall consumption on the long run?

I tried to use the deep sleep, but when I enable it the microcontroller is unable to communicate since the module is not reacting over UART unless during its very short wakeup phase. Is there a way to use deep sleep without this issue?

But, finally with the startup strategy I explained, it goes to the point that the sleeps are not really usefull since if I am right it is not used during startup and SPP Connect, which constitutes the main part of my communication time, and consumption (the real information will take only few milliseconds to be transmitted since it is only few strings of characters)

Thanks to the one who will read and answer this!
Best regards

Adrien Debelle