GSM/GPRS Module Series
M35 User Manual
M35_User_Manual Confidential / Released 5 / 85
3.7.1. UART Port ...................................................................................................................... 39
3.7.1.1. The Features of UART Port ............................................................................... 39
3.7.1.2. The Connection of UART .................................................................................. 40
3.7.1.3. Firmware Upgrade ............................................................................................. 42
3.7.2. Debug Port ..................................................................................................................... 42
3.7.3. UART Application ........................................................................................................... 43
3.8. Audio Interfaces ..................................................................................................................... 44
3.8.1. Decrease TDD Noise and Other Noise .......................................................................... 46
3.8.2. Microphone Interfaces Design ....................................................................................... 46
3.8.3. Receiver Interface Design .............................................................................................. 47
3.8.4. Earphone Interface Design ............................................................................................ 47
3.8.5. Loud Speaker Interface Design ..................................................................................... 48
3.8.6. Audio Characteristics ..................................................................................................... 48
3.9. PCM Interface ........................................................................................................................ 49
3.9.1. Configuration .................................................................................................................. 50
3.9.2. Timing ............................................................................................................................. 50
3.9.3. Reference Design .......................................................................................................... 52
3.9.4. AT Command ................................................................................................................. 52
3.10. SIM Card Interfaces .............................................................................................................. 53
3.10.1. SIM Card Application ...................................................................................................... 53
3.11. Behaviors of The RI ............................................................................................................... 57
3.12. Network Status Indication ...................................................................................................... 58
3.13. Operating Status Indication ................................................................................................... 59
4 Antenna Interface ............................................................................................................................... 61
4.1. RF Reference Design ............................................................................................................ 61
4.2. RF Output Power ................................................................................................................... 62
4.3. RF Receiving Sensitivity ........................................................................................................ 62
4.4. Operating Frequencies .......................................................................................................... 63
4.5. Antenna Requirement ........................................................................................................... 63
4.6. RF Cable Soldering ............................................................................................................... 64
5 Electrical, Reliability and Radio Characteristics ............................................................................ 65
5.1. Absolute Maximum Ratings................................................................................................... 65
5.2. Operating Temperature ......................................................................................................... 65
5.3. Power Supply Ratings ........................................................................................................... 66
5.4. Current Consumption ............................................................................................................ 67
5.5. Electro-static Discharge ........................................................................................................ 68
6 Mechanical Dimensions .................................................................................................................... 70
6.1. Mechanical Dimensions of Module ....................................................................................... 70
6.2. Recommended Footprint ....................................................................................................... 72
6.3. Top View of the Module ......................................................................................................... 73
6.4. Bottom View of the Module ................................................................................................... 73
7 Storage and Manufacturing .............................................................................................................. 74