User's Manual
Smart Machine Smart Decision
SIM868_Hardware_Design_V1.00 4 2016-06-20
4.8.2. SIM Card Design Guide ...................................................................................................................... 36
4.8.3. Design Considerations for SIM Card Holder ...................................................................................... 37
4.9. SD Interface ................................................................................................................... 39
4.10. I2C Bus .......................................................................................................................... 39
4.10.1. I2C Multiplexing Function .............................................................................................................. 39
4.11. ADC ............................................................................................................................... 40
4.12. Network Status Indication............................................................................................... 40
4.13. Operating Status Indication ............................................................................................. 41
4.14. RF Synchronization Signal ............................................................................................. 41
4.14.1. RF_SYNC Multiplexing Function ................................................................................................... 42
4.15. GNSS ............................................................................................................................. 42
4.15.1. GNSS Overview .............................................................................................................................. 42
4.15.2. Power on/down GNSS ..................................................................................................................... 42
4.15.3. 1PPS Output..................................................................................................................................... 42
4.16. Antenna Interface ........................................................................................................... 42
4.16.1. GSM Antenna Interface ................................................................................................................... 43
4.16.2. GNSS Antenna Interface .................................................................................................................. 46
5. PCB Layout ..................................................................................................... 48
5.1 Pin Assignment .............................................................................................................. 48
5.2 Principle of PCB Layout ................................................................................................. 49
5.2.1 Antenna Interface ................................................................................................................................ 49
5.2.2 Power Supply ...................................................................................................................................... 49
5.2.3 SIM Card Interface .............................................................................................................................. 49
5.2.4 Audio Interface.................................................................................................................................... 49
5.2.5 Others .................................................................................................................................................. 49
6. Electrical, Reliability and Radio Characteristics .......................................... 50
6.1 Absolute Maximum Ratings ........................................................................................... 50
6.2 Recommended Operating Conditions .............................................................................. 50
6.3 Digital Interface Characteristics ...................................................................................... 50
6.4 SIM Card Interface Characteristics ................................................................................. 50
6.5 SIM_VDD Characteristics .............................................................................................. 51
6.6 VDD_EXT Characteristics ............................................................................................. 51
6.7 Current Consumption(VBAT=4.0V) .......................................................................... 51
6.8 Electro-Static Discharge ................................................................................................. 52
6.9 Radio Characteristics ...................................................................................................... 52
6.9.1 Module RF Output Power ................................................................................................................... 52
6.9.2 Module RF Receive Sensitivity ........................................................................................................... 54
6.9.3 Module Operating Frequencies ........................................................................................................... 54
7. Manufacturing ................................................................................................ 55
7.1. Top and Bottom View of SIM868 ................................................................................... 55
7.2. Typical Solder Reflow Profile ........................................................................................ 55
7.3. The Moisture Sensitivity Level ....................................................................................... 55
7.4. Baking Requirements ..................................................................................................... 56