Sleep Current of XIAO nRF52840, Deep Sleep vs. Light Sleep

[msfujino]

I compared the sleep current between SystemOFFSleep(DeepSleep) and SystemONSleep(LightSleep). The board service package is “Seeed nRF52 Boards 1.1.1”. To enter sleep mode, I used NRF_POWER->SYSTEMOFF = 1; for DeepSleep and RTOS delay() function for LightSleep.
The pppk2 was used to measure the sleep current by applying 3.6V to the BAT pad on the backside of XIAO. The measured results were 2.4uA and 5.4A, with no significant difference.
Note that the quiescent current of the 3.3V LDO is measured even when the MPU enters sleep mode.

I hope this helps those considering sleep mode!

Flash_Light_Deep_Sleep.zip (1.1 KB)

[msfujino]

I studied the variation of the sleep current. We took a total of 39 measurements with 3 devices at different times and on different days. The results showed a variation of nearly 1uA for LightSleep, probably due to the RTOS running, but very little variation was seen for DeepSleepd.
(Note that the sleep currents shown here include the current drawn by the on-board 3.3V LDO).

[Eric_S]

Thanks for all thus tests. Although I’m not working on it now, this will help me reaching my goals for my datalogger.