Telit Wireless Solutions LM940 Design Guide

LM940 Hardware Design Guide
1VV0301352 Rev. 18 Page 5 of 75 2022-01-04
Not Subject to NDA
6.3.2.1. Fast Shutdown by AT Command 36
6.3.2.2. Fast Shutdown by GPIO 37
6.3.3. Unconditional Shutdown (Support Only on LM940 2.0) 38
Reset 39
6.4.1. Graceful Reset 40
6.4.2. Unconditional Hardware Reset 40
Dying Gasp 41
Communication Ports 41
6.6.1. USB Interface 42
6.6.2. SIM Interface 44
6.6.2.1. SIM Schematic Example 45
6.6.3. Control Signals 46
6.6.3.1. W_DISABLE_N 46
6.6.3.2. WAN_LED_N 46
6.6.4. General Purpose I/O 47
6.6.4.1. Using a GPIO Pin as Input 47
6.6.4.2. Using a GPIO Pin as Output 48
6.6.4.3. Dedicated I/O 48
6.6.5. I2C – Inter-Integrated Circuit 49
Using the Temperature Monitor Function 49
7. RF SECTION 50
Antenna Requirements 50
Main Antenna Requirements 50
Antenna Diversity Requirements 50
GNSS Receiver 51
7.4.1. GNSS RF Front End Design 51
Antenna Connection 52
7.5.1. Antenna Connector 52
7.5.2. Antenna Cable 53
7.5.3. Antenna Installation Guidelines 54
8. MECHANICAL DESIGN 55
General 55

Telit Wireless Solutions LM940 Specifications

General

Brand	Telit Wireless Solutions
Model	LM940
Category	Wireless modules
Language	English