we developed a custom board for the DA14680 and experience a BOD reset every 8 seconds.
The BOR only occurs with DCDC on.
After a BOR event the CRG_TOP->BOD_STATUS_REG Register reads the Decimal value 19, sometimes 21. It indicates a problem with the 1V8 or 1V8P rail, but I can not find the cause.
The DA14680 is in a aQFN-60 package.
Additionally we use a slightly modified version of the ble_peripheral example and the lates SDK (SDK_188.8.131.521)
Please find attached a trace of the BOR event.
The HIGH-Signal of the GPIO output is as follows:
1. Peak: The GPIO Port is set HIGH (port configured as input + pull-up) on entering the main() function and set immediately afterward to LOW (port configured as input + pull-down).
2. Peak: The GPIO Port is set HIGH (port configured as input + pull-up) on entering the vLPTimerCallback() function. It is set to LOW as part of the BOR I guess, because i did not set it to low manually.
3. Peak: The main() function got called again after the BOR event.
As stated in other forum posts and in the hardware guide a proper connection of the DCDC ground pad is important and a bad ground connection could be the cause. On the other hand you can see at the bottom side of the QFN package that all ground pads are interconnected.
Also the same code runs without issue on the DA14681 Development Kit - Basic.
Could you please give me additional help?