Current consumption issue of nRF21540 when using antenna 2

[Noah_iR]

Hello. 

There was a problem with high current consumption when using Antenna 2 in some products.

The failure rate seems to be less than 7%, and the current consumption increases by about 100uA.

Main MCU is nrf5340 and NCS version is v2.5.0

According to 3.4.[13] System: Increased supply current in Powerdown state with digital input pins at high level of "nRF21540_Revision_2_Errata_v1.2", the ANT_SEL pin should be held low in Power-down state. However, when we measured it, it seems to be held high, which may be causing the high current.

Since all pins that are mentioned on that errata report are handled by NCS library, I can't control that ANT_SEL pin.

I looked at the release notes for the other NCS versions and it doesn't seem like there was a fix for this.

Is there a NCS version that has a workaround for this?

[Kazi Afroza Sultana]

Hello,

There is a workaround here https://docs.nordicsemi.com/bundle/errata_nRF21540_Rev2/page/ERR/nRF21540/Rev2/latest/anomaly_540_13.html. I need to check if it is implemented in the mpsl driver.

You can check the trace codes for the devices (7%) with higher current draw, if these are earlier than stated in these errata then you should expect higher current draw for these devices:

https://docs.nordicsemi.com/bundle/errata_nRF21540_Rev2/page/ERR/nRF21540/Rev2/latest/anomaly_540_14.html