Reduce idle current below 5µA

RE: Reduce idle current below 5µA

Vidar Berg — Tue, 26 Aug 2025 14:11:48 GMT

The USB cable must still be connected to the DK to supply the supporting curcuitry like the interface MCU to avoid leakage. VDD is also closer to 3 volt.

RE: Reduce idle current below 5µA

Purvesh patel — Tue, 26 Aug 2025 13:35:35 GMT

Hello Vidar,

Sorry for the late reply, I got stuck in another issue.

After your recommendation, I tried different modes and obtained the following results:

Ammeter with Coin Cell

Configuration:

Result:

same result as when connected with usb

Source Meter

Configuration:

Result with vext->nRF switch off

saw increase in idle current to greater than 100ua!!

Result with vext-> nrf switch on

RE: Reduce idle current below 5µA

Vidar Berg — Fri, 22 Aug 2025 11:13:13 GMT

Hi,

It looks like you may be seeing some USB noise from the interface. Please try to use the PPK2 in source mode instead as this should lead to less noise in the measurements (see Measuring current in Source Meter mode).

[quote user=""]Power state control: Is there a way to force the CPU into a specific low-power state? I know pm_state_force() existed, but CONFIG_PM has been removed and the function is only available under #if defined(CONFIG_PM) || defined(__DOXYGEN__) in pm.h. [/quote]

This are no addtional power states implemented on the nrf52 series. It will enter System ON mode when entering the idle thread and the power managment is automated in HW by the power management unit (PMU).

[quote user=""]System poweroff with RTC wakeup: Can I use sys_poweroff() with the internal RTC timer as a wakeup source/interrupt?[/quote]

No, the clocks are powered off in System OFF so you need an external wakeup source.

[quote user=""]PM_S2RAM effectiveness: Does enabling CONFIG_PM_S2RAM make S2RAM the preferred power state when the system goes idle?[/quote]

This option is not available for this chip.

Best regards,

Vidar