Digi offers several options for interfacing to a low voltage (3.3V) system or a 5V system.
The simplest option is to use either the 3V XBee or a 9XTend OEM modules which supports a flexible input voltage range between 2.85 - 5.5VDC.
A second option if additional range or software performance is needed is to build a low voltage interface from your 5V device such as a Processor to the 3V device such as the Digi XBee modules (they require a regulated 3 VDC supply.)
To facilitate using a 5V device with a 3V device, we provide the attached reference schematic.
Please don't hesitate to let us know how we can further assist you.
Aug 23, 2017