nRF52840 - System ON mode with RTC wake-up and Lowest power consumption as possible

[Circuit Designers]

HI,

We are currently using System ON mode with RTC is running, and we are not facing any problem. But our concern is power consumption

We are using below peripherals with ble functionalities in our application...

1) 2 - SPI

2) 1 - TWI

3) 5 - GPIO

4) 4 - timers

We have one condition in that when we press one switch our device will go into we call it as "stand-by" mode in which only RTC is running rest all of the things we need to disable or stop to reduce power consumption. So we have below few question for we need help and those are ....

A) Can you tell us how we can reduce power consumption ?

B) Which peripherals and how we can disable them ?

C) What else we need to turn off and need to take care ?

Thanks

Regards

Vivek

[Circuit Designers]

i am already doing all three points you told me to do.

By doing those i am getting 1.4mA current after disabling all and doing all you mentioned.

Our BLE chip is consuming 1.0mA to 1.2mA  current out of  1.4mA.

Any further solution ?

Thanks

[Stian Røed Hafskjold]

Is 1.2 mA with DCDC enabled? And are you using nRF52832? If so, this number corresponds well with the HF clock and DMA bus being active. Sometimes the SPI and TWI will not release the clock if they are not disabled properly. Can you please post some code showing how you disable the peripherals?

There's more info about this in these posts:

https://devzone.nordicsemi.com/f/nordic-q-a/37754/putting-i2c-peripheral-back-into-lowest-power-state/145646#145646

https://devzone.nordicsemi.com/f/nordic-q-a/26030/how-to-reach-nrf52840-uarte-current-supply-specification/102605#102605

In the workaround proposed in the above two posts please change the xx part of the register address to the peripheral you are using: 0x400xxFFC

You can find the base address for the different peripherals here: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/memory.html?cp=2_1_0_7_3#topic