HUAWEI ME909 Series LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Issue V0.3 (2013-05-21)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
26
Figure 3-4
Connections of the POWER_ON_OFF pin
3.4.3
RESIN_N Pins
The RESIN_N pin is used to reset the module
’s system. When the software stops
responding, the RESIN_N pin can be pulled down to reset the hardware.
Pull up resistor is never needed for this pin.
Figure 3-5
Connections of the RESIN_N pin
As the RESIN_N and POWER_ON_OFF signals are relatively sensitive, it is
recommended that you install a 10 nF
–0.1 µF capacitor near the RESIN_N and
POWER_ON_OFF pins of the interface for filtering. In addition, when you design a
circuit on the PCB of the interface board, it is recommended that the circuit length not
exceed 20 mm and that the circuit be kept at a distance of 2.54 mm (100 mil) at least
from the PCB edge. Furthermore, you need to wrap the area adjacent to the signal
wire with a ground wire. Otherwise, the module may be reset due to interference.