Quectel EC21 Series, Hardware Design

Page: 5 / 95

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design Confidential / Released 4 / 94
Contents
About the Document ................................................................................................................................ 2
Contents .................................................................................................................................................... 4
Table Index ............................................................................................................................................... 6
Figure Index .............................................................................................................................................. 8
1 Introduction ..................................................................................................................................... 10
1.1. Safety Information ..................................................................................................................11
2 Product Concept ............................................................................................................................. 12
2.1. General Description .............................................................................................................. 12
2.2. Key Features ......................................................................................................................... 13
2.3. Functional Diagram ............................................................................................................... 16
2.4. Evaluation Board ................................................................................................................... 16
3 Application Interfaces ..................................................................................................................... 17
3.1. General Description .............................................................................................................. 17
3.2. Pin Assignment ..................................................................................................................... 18
3.3. Pin Description ...................................................................................................................... 19
3.4. Operating Modes .................................................................................................................. 28
3.5. Power Saving ........................................................................................................................ 28
3.5.1. Sleep Mode.................................................................................................................. 28
3.5.1.1. UART Application ............................................................................................... 28
3.5.1.2. USB Application with USB Remote Wakeup Function ....................................... 29
3.5.1.3. USB Application with USB Suspend/Resume and RI Function .......................... 30
3.5.1.4. USB Application without USB Suspend Function ............................................... 31
3.5.2. Airplane Mode .............................................................................................................. 32
3.6. Power Supply ........................................................................................................................ 32
3.6.1. Power Supply Pins ....................................................................................................... 32
3.6.2. Decrease Voltage Drop ................................................................................................ 33
3.6.3. Reference Design for Power Supply ............................................................................ 34
3.6.4. Monitor the Power Supply ............................................................................................ 35
3.7. Turn on and off Scenarios ..................................................................................................... 35
3.7.1. Turn on Module Using the PWRKEY ........................................................................... 35
3.7.2. Turn off Module ............................................................................................................ 37
3.7.2.1. Turn off Module Using the PWRKEY Pin ........................................................... 37
3.7.2.2. Turn off Module Using AT Command ................................................................. 37
3.8. Reset the Module .................................................................................................................. 38
3.9. USIM Card Interface ............................................................................................................. 39
3.10. USB Interface ........................................................................................................................ 41
3.11. UART Interfaces .................................................................................................................... 43
3.12. PCM and I2C Interfaces ........................................................................................................ 45
3.13. ADC Function ........................................................................................................................ 48
3.14. Network Status Indication ..................................................................................................... 49
Quectel
Confidential