User's Manual
Table Of Contents
- 1 Introduction
- 2 Module Power
- 3 Physical Interfaces
- Module Mounting to Host Board (Reference)
- Connectors
- Connectors
- I/O Connector Pin Assignments
- Circuit Protection
- Antenna
- Control Connector Signal Functions
- Module Power (Pins 85, 87, 89, 91, 93, 95, 97, 99)
- Power Control (Pin 35) - (PWR_CTL)
- Level Translation Reference Power (Pin 77)
- USB (Pins 1, 3, 5, 7, 9)
- General Purpose Input/Output Interface
- RTC Sleep
- Serial Interfaces & Handshake (Pins 11, 13, 15, 17, 19, 21, 23, 25)
- Multi-Channel Serial Interface (MCSI) – (Pins 12, 14, 16, 18)
- VBackup Input (Pin83)
- Using VBackup
- Analog-to-Digital Input (Pin 74)
- Handset Microphone Input (Pins 65, 67)
- Handset Microphone Bias Output (Pin 63)
- Handset Speaker Output (Pins 71, 73)
- Headset Microphone Input (Pin 55)
- Headset Microphone Bias Output (Pin 53)
- Headset Speaker Output Left & Right (Pins 57, 59)
- Headset Output Common Mode (Pin 61)
- Headset Detect (Pin 47)
- Subscriber Identity Module (SIM) Carrier (Pins 76, 78, 80, 82, 84)
- 4 Hardware Design
- General Design Guidelines for Using Novatel Wireless M2M GSM Modules
- Enabling the Transmission Modes for the GSM/GPRS Services
- Voice Communication
- Circuit-Switched Data
- SMS: Short Message Services
- Provisioning The SIM
- GSM Services Supported by the Novatel Wireless M2M Enabler IIIG Module
- GPRS Services Supported by the Novatel Wireless M2M Enabler IIIG Module
- Selecting the GSM Modes of Operation
- 5 Setup and Initialization
- 6 Integration and Testing
49 novatelwireless.com
applications where antenna quality is less than ideal, it is recommended to have a low pass
filter (Pi structure with N=3) in the RF path to the antenna. This is a secondary plan should
there be a need to lower harmonic levels at frequencies above the PCS band. The pad
structure may also be used to match the antenna load impedance, if required. If it is not
needed, a capacitor of low reactance may be used to bridge the Pi structure.
The RF cable going between the Enable module and the antenna is very lossy, therefore, the
length of this cable should be kept as short a possible.
VBAT Input
The Enabler Vbat input can have a relative high current draw that can fluctuate rapidly,
especially when transmitting at max power and burst mode. The Vbat interface must be
designed to provide the required instantaneous voltage and current with minimal voltage
droop. This includes both sufficient bulk decoupling capacitance as well as adequate layout
provisions.
When laying out the connections to the Enabler interface connector, it is tempting to use
traces of the same width as the connector pins. However, this is a very compact connector
and traces of that width will not have sufficient copper. Similar to the discussion on thermal
relief, the use of narrow traces to connect the Vbat pins to the source voltage can act like a
high impedance and cause a significant voltage droop when higher currents are required as
shown in Figure 4.