3.9. UART Interface ........................................................................................................................ 35
3.9.1. The Connection of UART ............................................................................................... 36
3.9.2. UART Application ........................................................................................................... 38
3.10. Behavior of the RI .................................................................................................................... 39
3.11. Analog Audio Interface ............................................................................................................ 40
3.11.1. Decrease TDD Noise and Other Noise .......................................................................... 41
3.11.2. Microphone Interfaces Application ................................................................................. 42
3.11.3. Receiver and Speaker Interface Application .................................................................. 43
3.11.4. Earphone Interface Application ...................................................................................... 45
3.12. PCM and I2C Interface ............................................................................................................ 46
3.13. USIM Card Interface ................................................................................................................ 48
3.13.1. USIM Card Application ................................................................................................... 48
3.13.2. Design Considerations for USIM Card Holder ............................................................... 50
3.14. USB Interface .......................................................................................................................... 53
3.15. ADC Function .......................................................................................................................... 54
3.16. Network Status Indication ........................................................................................................ 55
3.17. Operating Status Indication ..................................................................................................... 56
4 Antenna Interface ............................................................................................................................... 58
4.1. Antenna Interface .................................................................................................................... 58
4.1.1. Pin Definition .................................................................................................................. 58
4.1.2. Operating Frequency ..................................................................................................... 58
4.1.3. Reference Design .......................................................................................................... 59
4.2. Antenna Installation ................................................................................................................. 59
4.2.1. Antenna Requirement .................................................................................................... 59
4.2.2. Install the Antenna with RF Connector .......................................................................... 59
5 Electrical, Reliability and Radio Characteristics ............................................................................ 62
5.1. Absolute Maximum Ratings ..................................................................................................... 62
5.2. Power Supply Ratings ............................................................................................................. 63
5.3. Operating Temperature ............................................................................................................ 63
5.4. Current Consumption .............................................................................................................. 64
5.5. RF Output Power ..................................................................................................................... 66
5.6. RF Receiving Sensitivity .......................................................................................................... 66
5.7. Electrostatic Discharge ............................................................................................................ 67
6 Mechanical Dimensions .................................................................................................................... 68
6.1. Mechanical Dimensions of the Module.................................................................................... 68
6.2. Footprint of Recommendation ................................................................................................. 70
6.3. Top View of the Module ........................................................................................................... 71
6.4. Bottom View of the Module ...................................................................................................... 71
7 Storage and Manufacturing .............................................................................................................. 72
7.1. Storage..................................................................................................................................... 72
7.2. Manufacturing and Welding ..................................................................................................... 72
7.3. Packaging ................................................................................................................................ 73