Power Supply - Fibocom L850-GL Series Hardware Manual

Reset Value: The initial status after module reset, not the status when working.
H: High Voltage Level

L: Low Voltage Level

PD: Pull-Down

PU: Pull-Up

T: Tristate

OD: Open Drain

PP: Push-Pull

PI: Power Input

PO: Power Output

Note:
Digital IO pins CANNOT be connected to power directly.
The unused pins can be left floating.
All 3.3V ports are based on +3.3V power domain. When the power supply range is
3.135V~4.4V, the 3.3V ports voltage will follow the change of power supply range.

3.2 Power Supply

The power interface of L850 module is shown in the following table:
Pin Pin Name
2, 4, 70, 72, 74 +3.3V
36 UIM_PWR
L850 module uses PCIe interface. According to the PCIe specification, the PCIe Vmain should be used as
the +3.3V power source, not the Vaux. The Vaux is the PCIe backup power source and it is not sufficient
as the power supply. In addition, the DC/DC power supply other than PCIe ports should not be used as
the external power cannot control the module status through the PCIe protocol.
3.2.1 Power Supply
The L850 module should be powered through the +3.3V pins, and the power supply design is shown in
Figure 3-2:
Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved.
FIBOCOM L850-GL Series Hardware Guide
I/O Pin Description
PI Power supply input
PO USIM power supply
DC Parameter (V)
Minimum Typical
Value Value
3.135 3.3
1.8V/3V
-
Maximum
Value
4.4
-
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