nrf9160 ensure COEX1 is input/floating

[tpg]

Hi,

We use SDK 2.5.2 on a nrf9160. And have a hardware issue due to a too late update with the first boards. The GNSS LNA enable is wrongly connected to COEX1.

COEX0 is not accessible, but COEX2. A quick possible fix would be to connect COEX2 to COEX1, or alternatively some constant power.

Can we consider COEX1 to be floating/input as default?

It seems a bit unclear to me, if it always outputs PPS? Is PPS actually implemented?

Some parts of the documentation say it 'can' output PPS, so we can disable it?

Some part refer to the SDK for controlling it, seems with 2.6.99 there is some functionality to disable it. But, what would be the default status with SDK 2.5.?

When PPS is disabled in a newer SDK, can we consider the pin floating?

Best,

Thomas

[Charlie]

Hi Thomas,

In the document, we only have the following description: When the LTE modem is not active, the COEX interface floats.

The pin COEX1 floating/low state when it is disabled while modem is active is not clear. I will request a measurement in the lab to confirm.

I will update to you once this is done.

Best regards,

Charlie