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L850-GL Hardware User Manual Page 21 of 54
PU: Pull-Up
T: Tristate
OD: Open Drain
PP: Push-Pull
PI: Power Input
PO: Power Output
Note:
The unused pins can be left floating.
3.2 Power Supply
The power interface of L850 module as shown in the following table:
Pin
Pin Name
I/O
Pin Description
DC Parameter
(
V
)
Minimum
Value
Typical
Value
Maximum
Value
2, 4, 70, 72, 74 +3.3V
PI
Power supply input
3.135
3.3
4.4
36
UIM_PWR
PO
USIM power supply
-
1.8V/3V
-
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:
Figure 3-2 Power Supply Design