lowest possible current consumption when system is running (nRF52810)

[buja]

Chip - BT832AF (nRF52810 QFAA)

SDK- nRF5_SDK_17.0.2_d674dde

SD - s112_nrf52_7.2.0

2V- power supply

  My application need not to be very fast, but is extremely concerned about the power consumption. My application  sends beacon, communicates with sensor (SPI).

My device is drawing a current of 330nA during system OFF, 1 uA during system ON. are these the lowest figures I can get ?

Is it possible to reduce the clock frequency to save even more current during the controller is running/systemON/OFF ?

[Simonr]

Hi

1. By default most of our examples are configured to not use RAM retention. If you're using a timer for wake up, that is why you're seeing ~1uA. Please check out the various sleep current consumption scenarios here.

Best regards,

Simon

[buja]

Hi Simon,

thank you for your reply. 

1) I checked current consumption  for various scenarios in systemON and it is same with timer/gpioTE and without timer/gpioTE.

clock source is XTAL

External clock accuracy used in the LL to compute timing is NRF_CLOCK_LF_ACCURACY_20_PPM

Actually the current consumption is not stable and is varying from 850nA to 1.1uA from time to time. Do you have any suggestion ?

2) I saw in many answers in forum that calling "sd_app_evt_wait" will put device in system ON without RAM retention. But when i read the register "RAM[n].POWER (n=0..7)" before calling sd_app_evt_wait(), the value is 0xFFFF which means that RAM will be retained according to the spec. Then how RAM doesn't retain data during system ON?

From the above table I am assuming that disabling RAM retention during systemON is only possible by disabling the power to the RAM. Is my understanding correct ?  Also, if RAM is not retained, Will the code be moved from flash to RAM each time device is waking up from systemON ? 

Best regards,

Nizar