Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

NewtoM — Thu, 03 May 2018 13:19:11 GMT

Thank you!

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

Stian Røed Hafskjold — Thu, 03 May 2018 12:28:09 GMT

The bugfix timer that was introduced in SDK14 also needs to be shut down before sleep in order to get lower consumption.

NRF_ESB_BUGFIX_TIMER->TASKS_SHUTDOWN = 1;

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

NewtoM — Wed, 07 Mar 2018 12:34:30 GMT

Dear Torbjørn,

you're right. I inserted the proposed line right after nrf_esb_disable(); and my current draw dropped to 2.7 µA in "sleep" mode after using ESB in TX mode.

Thank you very much!

Tamas

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

ovrebekk — Wed, 07 Mar 2018 08:30:34 GMT

Hi Tamas

It sounds to me like you have hit product anomaly #78, which makes the timer module draw excessive current in sleep unless the SHUTDOWN task is triggered.

Can you try to shut down the timer before entering sleep?

Like this:

NRF_ESB_SYS_TIMER->TASKS_SHUTDOWN = 1;

Best regards
Torbjørn Øvrebekk

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

NewtoM — Tue, 06 Mar 2018 12:57:54 GMT

In the meantime I repeated the test with the nRF52840 Preview DK (External 3V supply, nRF only setting). The problem DOES exist there, too. Current consumption after disabling ESB and calling nrf_pwr_mgmt_run() in a loop:

17 µA if the ESB was previously initialized as PTX, and
2.7 µA if the ESB was previously only initalized as PRX.

In System Off mode the current consumption drops to 1.8 µA in both cases.

RE: Higher current draw in System On low-power mode after ESB PTX than after ESB PRX

NewtoM — Tue, 06 Mar 2018 07:25:36 GMT

The issue is still relevant. While 1.4 µA is lower than the "sleep" current of competing devices, 8 µA would rule out the Nordic chip in our intended scenario.