What pin on the Boron is “Supply Input Voltage” referring to? VBUS is typically 5V when powered from USB. The only other input supply voltage I see is LiPo+.
What is the input voltage range for the VBUS pin to utilize the lipo battery charger?
That’s probably due to that value also being present on Argon and Xenon where you could power the device via the 3V3 pin, but for the Boron that’s not an option.
VUSB PIN
The pin is internally connected to the VBUS of the USB port. The nominal output should be around 4.5 to 5 VDC when the device is plugged into the USB port and 0 when not connected to a USB source. You can use this pin to power peripherals that operate at such voltages. Do not exceed the current rating of the USB port, which is nominally rated to 500mA.
LiPo
If you want to make your projects truly wireless, you can power the device with a single cell LiPo (3.7V). The Boron has an on board LiPo charger that will charge and power the device when USB source is plugged in, or power the device from the LiPo alone in the absence of the USB.
Li+ PIN
This pin is internally connected to the positive terminal of the LiPo connector. You can connect a single cell LiPo/Lithium Ion or a DC supply source to this pin for powering the Boron. Remember that the input voltage range on this pin is 3.6 to 4.2 VDC.
For the Boron 2G/3G version, make sure that the external DC supply is able to support 2A peak current requirements.
3V3 PIN
This pin is the output of the on board 3.3V step-down switching regulator (Torex XC9258A). The regulator is rated at 1000mA max. When using this pin to power other devices or peripherals remember to budget in the current requirement of the Boron first. Unlike the Xenon or the Argon, this pin CANNOT be used to power the Boron.
Seeing that detail is good to know and for you and I who understand the separation as depicted in your extract above - however in the module overview pinout, which many will look at first, the PCB silkscreen on that pin is confusing and should then be changed to match the label in red as they indicate they are the same net.