Reference Manual
Table Of Contents
- Digi XBee® 3 RF Module Hardware Reference Manual
- General XBee 3 specifications
- IEEE 802.15.4-specific specifications
- Mechanical drawings
- Pin signals
- Design notes
- Regulatory information
- XBIB-C development boards
- Manufacturing information
- Troubleshooting
Troubleshooting Brownout issue
Digi XBee® 3 RF Module Hardware Reference Manual
75
Brownout issue
The XBee 3 RF Module uses a Silicon Labs EFR32MG System on Chip (SoC). Silicon Labs has announced
an intermittent restarting issue with EFR32MG revision B SoCs which can be caused by voltage
brownout or supply dips during power-on. The information below is provided to help you avoid this
issue.
Voltage brownout
This issue may occur if the VCC pin momentarily dips past the specified lower bound of the voltage
range (2.1 V) into the range of 1.8 V to approximately 1.2 V. When the supply returns to normal levels
the SoC may not restart properly and enter an unresponsive state. You must fully power cycle the
XBee 3 to recover from this state. The failure rate tends to increase with slower ramp down rates of
the power supply; for more details see RMU_E203 — AVDD Ramp Issue. If the part is kept within the
operational voltage range specified in Power requirements, the conditions to cause this failure are
never met.
Voltage ramp up discontinuities
This issue is similar to the voltage brownout issue. The SoC may fail to start if, during power on, the
supply powering the VCC pin experiences discontinuities in the voltage rise (in other words, dips) while
the voltage is in the range of approximately 1.2 to 1.8 V. You must fully power cycle the XBee 3 to
recover from this state. The failure rate tends to increase with slower ramp up rates of the power
supply; for more details see RMU_E203 — AVDD Ramp Issue. The issue can be avoided by ramping your
power supply steadily to the normal operating range.
How to distinguish revision B parts
Silicon Labs has corrected these issues in revision C of their SoC. We are printing the SoC revision on
the XBee 3 label to make it easy to distinguish. The letter is located on the right edge of the sticker
and rotated 90 degrees. There were some parts made before this issue was identified that do not
have the revision letter printed on the sticker. All of those parts are revision B parts.