Specifications

Chapter 9 – SocketModem CDMA (MTSMC-C)
Multi-Tech Systems, Inc. Universal Socket Hardware Guide for Developers (S000342C) 126
Application Notes
SocketModem Interfaces
Flashing LED Interface
The flashing LED signal is used to indicate the working mode of the SocketModem.
LED and SocketModem Status
Signal SocketModem Status
OFF Download mode or switched OFF>
Continuously lit Switched ON (not registered on the network) ON
Flashing Switched ON (registered on the network)
RF Interface
The impedance is 50 Ohms nominal.
RF Connector
The RF connector is MMCX standard type. An antenna can be directly connected through the
mating connector or using a small adapter.
General Guidelines for the Use of the SocketModem
Hardware and RF
• Ground plane: Multi-Tech recommends having a common ground plane for analog, digital, and
RF grounds.
• ESD protection on serial link,
• Possible spurious emission radiated by the application to the RF receiver in the receiver band.
The Antenna
The antenna sub-system and integration in the application is a major issue: Choice of antenna
cable (type, length, performances, thermal resistance, etc.) These elements could affect CDMA
performances such as sensitivity and emitted power.
The antenna should be isolated as much as possible from the digital circuitry including the interface
signals.
Multi-Tech recommends shielding the terminal. On terminals including the antenna, a poor
shielding could dramatically affect the sensitivity of the terminal. Subsequently, the power emitted
through the antenna could affect the application.
Soldering and Cleaning the SocketModem
The pins of the SocketModem may be hand soldered or wave soldered. If wave soldered, the
temperature on the top of the SocketModem must not exceed 100° C.
There should be no solvent or water washing of the SocketModem.
Do not use a hot air gun on the SocketModem.
Initial Configuration Using Mobile PhoneTools
For initial configuration of your wireless device, Multi-Tech offers a Windows-based mobile
PhoneTools application.
To load Mobile PhoneTools: Click the Mobile PhoneTools icon on the product CD and follow the
on-screen prompts.