how much consume nrf51822 in low power, datasheet and mesure are not the same !?!?

[bibi]

Hello,

what do I need to pay attention to calculate the consumption of nrf51822 in low power mode (sleep).

I make this simple program :

===================================

enable Low frequency quartz => Ix32k = max 1uA

enable watchdog => Iwdt = typ 0.1uA

NRF_POWER->RAMON = 0;

NRF_RADIO->POWER = 0;

NRF_POWER->TASKS_LOWPWR = 1;

__WFI();

===================================

so the consumption must be 1uA + 0.1uA ~=1.1uA but I mesure a consumption of 2.28uA

I try the same program with only the LFCLCK => calculated : max 1uA => mesured : 2.1uA

with no wdt and no LFCLCK => mesured : 1.43uA

Am I missing something in my calculs ? have anyone an idee ? Thank you

[Stefan Birnir Sverrisson]

Hi

The expected current consumption is actually System_On_mode + LFCLK_crystal_WDT = 2.6 + 0.4 + 0.1 = 3.1uA, so your observed current consumption of your specific nRF51 chip is surprisingly low. The chip remains in System_On low power mode when you call __WFI.

More information on current consumption is given in the current consumption guide.