This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

System OFF mode(0.3uA) in nrf52832

Hello everyone,

I trying my nrf52832 getting ultra low power current conception mode using System OFF mode(0.3uA). I using SDK 15.2 ble_app_beacon example I change 32KHZ internal RC configuration this link and sd_power_system_off();  this command for low power conception but my module(PCA10040) take 5mA current for advertising. I need get ultra low power conception for sleep and advertising both side please share any example code or refer link to achieve this concept.

DK:PCA10040

SDK:15.2

Parents
  • Hi

    It seems like you're misunderstanding the product specifications somewhat. 0.3uA will not be achievable while advertising, as the radio is not active while in SYSTEM OFF mode. You can see in the PS, section 17.1.1 Electrical specification, that the current while the radio is active, will be between 4.1 and 7.1 depending on your output power. So if you're advertising very often, that means the application will draw current closer to this number in total. You can take a look at our current consumption guide for ways to minimize your current consumption.

    How much current does your chip use when it's in SYSTEM OFF mode now? I think this will be somewhat higher than 0.3uA, as the internal RC oscillator needs to wake up the SoftDevice in order to calibrate the oscillator to keep it from drifting. 0.3 uA should be achievable if you're using the external 32.768kHz crystal.

    Best regards,

    Simon

Reply
  • Hi

    It seems like you're misunderstanding the product specifications somewhat. 0.3uA will not be achievable while advertising, as the radio is not active while in SYSTEM OFF mode. You can see in the PS, section 17.1.1 Electrical specification, that the current while the radio is active, will be between 4.1 and 7.1 depending on your output power. So if you're advertising very often, that means the application will draw current closer to this number in total. You can take a look at our current consumption guide for ways to minimize your current consumption.

    How much current does your chip use when it's in SYSTEM OFF mode now? I think this will be somewhat higher than 0.3uA, as the internal RC oscillator needs to wake up the SoftDevice in order to calibrate the oscillator to keep it from drifting. 0.3 uA should be achievable if you're using the external 32.768kHz crystal.

    Best regards,

    Simon

Children
  • Thanks for replay simonr,

        for (;;)
        {
            idle_state_handle();
        			err_code = sd_ble_gap_adv_stop(m_adv_handle);
    			APP_ERROR_CHECK(err_code);
    
    			advertising_init();
    			
    			err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);
    			APP_ERROR_CHECK(err_code);
    			nrf_delay_ms(1000);
    			NRF_POWER->SYSTEMOFF=1;
    			sd_power_system_off(); 
    		nrf_delay_ms(5000);
    		}

    I using ble_app_beacon code for sleep current measurement. i check my nrf connect doesn't show any advertising data but 3uA current show constantly. i know its wrong method how can i find advertising current and sleep current on my module. please suggest any correct way possible to archive ultra lower current conception.

Related