User's Manual
GSM/GPRS/GNSS Module Series
MC20 Hardware Design
MC20_Hardware_Design Confidential / Released 4 / 95
3.4.3. Summary of GSM and GNSS Parts’ State in All-in-one Solution .................................. 37
3.4.4. Summary of GSM and GNSS Parts’ State in Stand-alone Solution ............................. 37
3.5. Power on and down .............................................................................................................. 38
3.5.1. Power on ..................................................................................................................... 38
3.5.2. Power down ................................................................................................................. 40
3.5.2.1. Power down Module Using the PWRKEY Pin ................................................. 40
3.5.2.2. Power down Module Using AT Command ....................................................... 41
3.5.2.3. Power down GNSS Part Alone Using AT Command ....................................... 42
3.5.2.4. Under-voltage Automatic Shutdown ................................................................ 42
3.6. Serial Interfaces .................................................................................................................... 43
3.6.1. UART Port ................................................................................................................... 45
3.6.1.1. Features of UART Port .................................................................................... 45
3.6.1.2. The Connection of UART ................................................................................ 46
3.6.1.3. Firmware Upgrade ........................................................................................... 48
3.6.2. Debug Port................................................................................................................... 49
3.6.3. Auxiliary UART Port and GNSS UART Port ................................................................. 49
3.6.3.1. Connection in All-in-one Solution ..................................................................... 49
3.6.3.2. Connection in Stand-alone Solution ................................................................ 50
3.6.4. UART Application ......................................................................................................... 51
3.7. Audio Interfaces .................................................................................................................... 52
3.7.1. Decrease TDD Noise and Other Noises ...................................................................... 54
3.7.2. Microphone Interfaces Design ..................................................................................... 54
3.7.3. Receiver and Speaker Interface Design ...................................................................... 55
3.7.4. Earphone Interface Design .......................................................................................... 56
3.7.5. Loud Speaker Interface Design.................................................................................... 56
3.7.6. Audio Characteristics ................................................................................................... 57
3.8. SIM Card Interface ................................................................................................................ 57
3.9. ADC ...................................................................................................................................... 61
3.10. Behaviors of the RI ............................................................................................................... 61
3.11. Network Status Indication ...................................................................................................... 63
3.12. EASY Autonomous AGPS Technology ................................................................................. 64
3.13. EPO Offline AGPS Technology ............................................................................................. 64
3.14. Multi-tone AIC ....................................................................................................................... 65
4 Antenna Interface ............................................................................................................................ 66
4.1. GSM Antenna Interface ......................................................................................................... 66
4.1.1. Reference Design ........................................................................................................ 66
4.1.2. RF Output Power ......................................................................................................... 67
4.1.3. RF Receiving Sensitivity .............................................................................................. 68
4.1.4. Operating Frequencies ................................................................................................ 68
4.1.5. RF Cable Soldering ..................................................................................................... 68
4.2. GNSS Antenna Interface ....................................................................................................... 69
4.2.1. Antenna Specifications ................................................................................................ 69
4.2.2. Active Antenna ............................................................................................................. 70
4.2.3. Passive Antenna .......................................................................................................... 71