W_Disable# Signal - Huawei MC509 Hardware Manual

HUAWEI MC509 CDMA Mini PCIe Module
Hardware Guide
As the RESIN_N signal is relatively sensitive, it is recommended that you install a

10 nF to 0.1 µF capacitor near the RESIN_N pin 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 should not exceed 20 mm and that the circuit
should 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.
The maximum Forward Voltage Drop of the diode used in the module is 0.6 V. So

when the host wants to reset the module, the low-level voltage in the RESIN_N pin
should be below 50 mV.
The MC509 Mini PCIe module supports hardware reset function. If the software of the
MC509 Mini PCIe module stops responding, you can reset the hardware through the
RESIN_N signal as shown in Figure 3-6 . When a low-level pulse is supplied through
the RESIN_N pin, the hardware will be reset. After the hardware is reset, the software
starts powering on the module and reports relevant information according to the actual
settings.
Figure 3-6 Reset pulse timing

3.4.4 W_DISABLE# Signal

The W_DISABLE# signal is provided to allow users to disable wireless
communications of the module.
The W_DISABLE# signal is internally pulled up, which is automatically on when 3.3 V
is applied and it is active-low.
Issue 03 (2014-12-26)
The RESIN_N pin must not be pulled down for more than 1s.
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The RESIN_N pin is optional, which can be connected or not.

The maximum Forward Voltage Drop of the diode used in the module is 0.6 V.
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Description of the Application Interfaces
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