ZTE Corporation ZM8300G 用户手册
ZTE ZM8300G Module Hardware User Manual
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19
3.3 Power Interfaces
3.3.1
Overview of Power Pins
The LGA interface unit of the ZM8300G module provides the following power pins:
VSYS: Power supply for module
VIO:
power output pin of the module
3.3.2
VSYS Primary Power
The ZM8300G module uses the VSYS pins (PIN 48 and PIN 49 is the interface for
LGA), which are Power supply for module, to receive power provided by an external power
supply. The input voltage should be within the range of 3.0 V to 4.2 V (with the typical value
being 3.6 V), and the input current should not be less than 1 A.
Considering all external applications of the ZM8300G module, focus on the specifications
of the external power supply. As the network environments differ from each other dramatically,
when the ZM8300G module sends signals at the maximum transmit power, the peak
operating current for module is more than 600mA,which continued for 10ms. In this case,
ensure that the voltage drop of the external power supply is not lower than the operating
voltage of the ZM8300G module (3.0 V). Otherwise, abnormal case such as a ZM8300G
module reset may occur.
For external power supplies, ensure that they provide adequate and steady input
capabilities. Buck or Boost/LDOs/Battery with the output capability not less than 1 A are
required. In addition, ensure that the power circuit on the external system board is as short as
possible and is wide enough and that a good backflow is ormed on the ground plane. Connect
energy storage capacitors of at least one hundred uFin parallel at power interfaces of the
module, with the goal of reducing instantaneous power fluctuations. Moreover, it is
recommended that customers add a ferrite-bead(or a same-package zero-ohm resistor) to
the VSYS power circuit in order to reduce EMI. Ensure that the rated current of the selected
ferrite-bead meets the requirement. In addition, carry out ESD measures for the power
interfaces. Figure 3-2 illustrates the recommended power supply circuit.
VDD_3V6
VSYS
1
5
0
u
F
4
7
u
F
2
2
u
F
1
u
F
0
.1
u
F
3
3
p
F
TVS
Bead