Knowledge Base

SX1261/2 TCXO and sleep

I am using SX1262 and TCXO in my project. ( LORA mode )
After POR and automatic calibrations ( chip is doing it automatically after reset ) i get directly XOSC_START_ERR ( function GetDeviceErrors ).
And this is a normal situation because auto calibration after POR doesn't know that TCXO is used and as default trying to do it with XTAL.

Next I am clearing this error using ClearDeviceErrors.
( By the way, there is also a bug in the documentation. In documentation to clear the errors is enough to write 0x07 0x00. In reality we need to write : 0x07 0x00 0x00. Simmilar like ClearIrqStatus function )

Write the whole configuration also with SetDIO3AsTCXOCtrl and calibration.
After this error isn't present.
So far is ok, and error isn't present.

But if we call SetSleep in warm start mode or SetRxDutyCycle and next SetStandby
we got again present error XOSC_START_ERR ( but SX1262 is working correctly with TCXO )

Going to sleep once seems that error is appearing again.

Any ideas?

Thanks for reporting this.

This is actually a bug. When leaving leaving "sleep mode" with a warm start (i.e. with device configuration in retention), the flag "XOSC_START_ERR " is not properly reconfigured. But, as you mentioned, the device is still functional with the TCXO.

The next release of the datasheet will include an explanation about this behavior.