Quectel M85, Hardware Design

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GSM/GPRS Module
M85 Hardware Design
M85_Hardware_Design Confidential / Released 3 / 92
Contents
About the document ................................................................................................................................... 2
Table Index ................................................................................................................................................... 6
Figure Index ................................................................................................................................................. 7
1 Introduction .......................................................................................................................................... 9
1.1. Safety Information ................................................................................................................... 9
2 Product Concept ................................................................................................................................ 11
2.1. General Description ............................................................................................................... 11
2.2. Key Features ......................................................................................................................... 11
2.3. Functional Diagram ............................................................................................................... 13
2.4. Evaluation Board ................................................................................................................... 14
3 Application Interface ......................................................................................................................... 15
3.1. Pin Of Module ........................................................................................................................ 15
3.1.1. Pin Assignment .............................................................................................................. 15
3.1.2. Pin Description ............................................................................................................... 18
3.2. Operating Modes ................................................................................................................... 23
3.3. Power Supply ........................................................................................................................ 25
3.3.1. Power Features of Module ............................................................................................. 25
3.3.2. Decrease Supply Voltage Drop ...................................................................................... 25
3.3.3. Reference Design For Power Supply ............................................................................ 26
3.3.4. Monitor Power Supply .................................................................................................... 27
3.4. Power On and Down Scenarios ............................................................................................ 27
3.4.1. Power On ....................................................................................................................... 27
3.4.2. Power Down ................................................................................................................... 29
3.4.2.1. Power Down Module Using the PWRKEY Pin ................................................ 29
3.4.2.2. Power Down Module Using AT Command ...................................................... 30
3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown ...................................... 30
3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin ............................................. 31
3.4.3. Restart ............................................................................................................................ 32
3.5. Power Saving ........................................................................................................................ 33
3.5.1. Minimum Functionality Mode ......................................................................................... 33
3.5.2. SLEEP Mode .................................................................................................................. 34
3.5.3. Wake Up Module From SLEEP Mode ........................................................................... 34
3.5.4. Summary Of State Transition ......................................................................................... 34
3.6. RTC Backup .......................................................................................................................... 35
3.7. Serial Interfaces ..................................................................................................................... 36
3.7.1. UART Port ...................................................................................................................... 38
3.7.1.1. The Features of UART Port ............................................................................. 38
3.7.1.2. The Connection of UART ................................................................................ 39
3.7.1.3. Firmware Upgrade ........................................................................................... 41
3.7.2. Debug Port ..................................................................................................................... 42
3.7.3. Auxiliary UART Port ....................................................................................................... 42
Quectel
Confidential