GSM/GPRS Modules
GSM Module Audio Design Guide
GSM Module Audo Design Guide Confidential/Release 3 / 35
Contents
About the document ................................................................................................................................... 2
Contents ....................................................................................................................................................... 3
Table Index ................................................................................................................................................... 5
Figure Index ................................................................................................................................................. 6
1 Introduction .......................................................................................................................................... 7
1.1. Summary ...................................................................................................................................... 7
1.2. Safety Information ........................................................................................................................ 7
2 Audio Circuit Design ........................................................................................................................... 9
2.1. Audio Circuit Reference ............................................................................................................. 10
2.1.1. M1x ................................................................................................................................. 10
2.1.1.1. Microphone Reference Circuit .............................................................................. 10
2.1.1.2. Receiver Reference Circuit....................................................................................11
2.1.1.3. Headset Reference Circuit ................................................................................... 13
2.1.2. M95................................................................................................................................. 13
2.1.3. Microphone Reference Circuit ....................................................................................... 13
2.1.3.1. Receiver Reference circuit ................................................................................... 14
2.1.3.2. Headset Reference Circuit ................................................................................... 14
2.1.3.3. SPK Reference Circuit .......................................................................................... 15
2.1.4. M80................................................................................................................................. 16
2.1.4.1. Microphone Reference Circuit .............................................................................. 16
2.1.4.2. Receiver Reference Circuit................................................................................... 16
2.1.4.3. Headset Reference Circuit ................................................................................... 18
2.1.4.4. SPK Reference Circuit .......................................................................................... 18
2.2. Ringtone ..................................................................................................................................... 19
2.3. Hands-free Application at Channel AIN1/AOUT1 ...................................................................... 20
2.4. Suggestion for Audio Layout ...................................................................................................... 21
2.5. TDD Noise Solution.................................................................................................................... 21
2.6. Suggestion for Mechanical Design ............................................................................................ 22
2.7. Component of SPK .................................................................................................................... 25
2.8. Component of Microphone......................................................................................................... 26
3 Description and Suggestion ............................................................................................................. 27
3.1. AT Command ............................................................................................................................. 27
3.1.1. AT+QAUDCH ................................................................................................................. 27
3.1.2. How to Modify Volume ................................................................................................... 28
3.1.2.1. AT+QMIC .............................................................................................................. 28
3.1.2.2. AT+CLVL ............................................................................................................... 29
3.1.2.3. AT+QSIDET .......................................................................................................... 30
3.1.3. Echo Algorithm ............................................................................................................... 31
3.1.3.1. Description of Par0, Par2 and Par12 ................................................................... 33
3.1.3.2. Recommended Application Field .......................................................................... 34