System ON low power mode with soft device

[Julian_sanchez]

Hello,

We are using the nrf52832 in SES with the softdevice s112 (v7.2.0) and sdk17.1.0 in a custom board for a BLE application (that includes OTA DFU and a custom service). We want the application to go in low power mode after disconnecting from BLE, the following peripherals should remain working: SAADC, COMP, RTC, FDS, PWM and TWI. At the moment, when measuring the  current consumption in this mode is 2.3mA, but we have to reduce the power consumption <1mA for the application . We are running nrf_pwr_mgmt_run(), is there something else we are missing to reduce the power consumption?

we try also disabling the softdevice but the device went directly in SYSTEM OFF

[Sigurd]

Hi!

1) If you have DCDC components on the PCB, make sure to enable DCDC mode.

sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE);

2)

To lower the current more, you would likely need to disable SAADC and/or PWM.

[Julian_sanchez]

Hi Sigurd, thank you for your response.

We identified indeed that the SAADC or PWM were causing the high current consumption. We don't have DCDC components on the PCB, is it possible to disable the DCDC?

The SAADC is sampling with nrf_drv_saadc_sample() each 10 seconds while the PWM is started with nrf_drv_pwm_complex_playback() with an interrupt. How is the best way to handle these peripherals in the low power mode?
Does the current consumption decreases if the softdevice is disable? we have read that this is not recommended

[Sigurd]

Hi!

Julian_sanchez said:

We don't have DCDC components on the PCB, is it possible to disable the DCDC?

DCDC is default off. So if you don't have the DCDC components, then you don't need to take any action.

Julian_sanchez said:

The SAADC is sampling with nrf_drv_saadc_sample() each 10 seconds while the PWM is started with nrf_drv_pwm_complex_playback() with an interrupt. How is the best way to handle these peripherals in the low power mode?

Either don't use them that often, and/or fully disable them in your low power mode. nrf_drv_pwm_uninit() / nrf_drv_saadc_uninit()

 

Julian_sanchez said:

Does the current consumption decreases if the softdevice is disable? we have read that this is not recommended

No, this does not help.