I am having some trouble with my Atmega256RFR2.
Some background information:
I have created a custom PCB, this pcb contains the atmega256rfr2 with necessary circuitry.
It also contains a power circuit, an Attiny and a USB connector.
It works, i get wireless connection with the zigbee radio, i have connection and have tested the atmega mcu.
My problem:
The Zigbee radio is not able to recieve anything after the voltage rises abow 3.25.
Everything else like I/O pins work fine with voltages abow 3.25.
What i have done:
I am testing the wireless connection in Atmel Studio with the wireless composer 7.0 and i am able to hold a steady connection.
I have looked closely on the power signals while tuning the voltage up by small increments, nothing noticable is happening there.
I have bypassed the power circuit in case anything was wrong there.
I have ruled out that the ATtiny can be the problem, because i have another PCB without the ATtiny with the exact same case.
I am currently only powering the mcu and its external components with a lab bench power supply.
In the datasheet it is specified maximum voltage 3.6V. It is also stated in the datasheet about internal regulators.
I can not find the reason why the zibgee radio terminated its transmission when the voltage rises abow 3.25 volt.
Thanks in advance!