User's Manual

GSM/GPRS Module Series
M85 Hardware Design
M85_Hardware_Design Confidential / Released 3 / 88
Contents
About the Document ................................................................................................................................... 2
Contents ....................................................................................................................................................... 3
Table Index ................................................................................................................................................... 6
Figure Index ................................................................................................................................................. 7
1 Introduction .......................................................................................................................................... 9
1.1. Safety Information ................................................................................................................. 10
2 Product Concept ................................................................................................................................ 11
2.1. General Description ............................................................................................................... 11
2.2. Directives and Standards ...................................................................................................... 11
2.2.1. FCC Statement ............................................................................................................... 11
2.2.2. FCC Radiation Exposure Statement .............................................................................. 12
2.3. Key Features ......................................................................................................................... 12
2.4. Functional Diagram ............................................................................................................... 14
2.5. Evaluation Board ................................................................................................................... 15
3 Application Interface ......................................................................................................................... 16
3.1. Pin of Module ......................................................................................................................... 17
3.1.1. Pin Assignment .............................................................................................................. 17
3.1.2. Pin Description ............................................................................................................... 18
3.2. Operating Modes ................................................................................................................... 23
3.3. Power Supply ........................................................................................................................ 24
3.3.1. Power Features of Module ............................................................................................. 24
3.3.2. Decrease Supply Voltage Drop ...................................................................................... 24
3.3.3. Reference Design For Power Supply ............................................................................ 25
3.3.4. Monitor Power Supply .................................................................................................... 26
3.4. Power On and Down Scenarios ............................................................................................ 26
3.4.1. Power On ....................................................................................................................... 26
3.4.2. Power Down ................................................................................................................... 28
3.4.2.1. Power Down Module Using the PWRKEY Pin ................................................ 28
3.4.2.2. Power Down Module Using AT Command ...................................................... 29
3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown ...................................... 29
3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin ............................................. 30
3.4.3. Restart ............................................................................................................................ 31
3.5. Power Saving ........................................................................................................................ 32
3.5.1. Minimum Functionality Mode ......................................................................................... 32
3.5.2. SLEEP Mode .................................................................................................................. 33
3.5.3. Wake up Module from SLEEP Mode ............................................................................. 33
3.5.4. Summary of State Transition .......................................................................................... 33
3.6. RTC Backup .......................................................................................................................... 34