Quectel EC21 Series

LTE Standard Module Series
EC21_Series_Hardware_Design
9
/ 118
Contents
Safety Information...................................................................................................................................................... 3
About the Document..................................................................................................................................................5
Contents........................................................................................................................................................................ 9
Table Index.................................................................................................................................................................12
Figure Index............................................................................................................................................................... 14
1 Introduction....................................................................................................................................................... 16
1.1. Special Marks........................................................................................................................................18
2 Product Overview.............................................................................................................................................19
2.1. Frequency Bands and Functions....................................................................................................... 19
2.2. Key Features......................................................................................................................................... 20
2.3. Functional Diagram.............................................................................................................................. 23
2.4. EVB......................................................................................................................................................... 24
3 Application Interfaces..................................................................................................................................... 25
3.1. General Description..............................................................................................................................25
3.2. Pin Assignment..................................................................................................................................... 26
3.3. Pin Description...................................................................................................................................... 27
3.4. Operating Modes.................................................................................................................................. 37
3.5. Power Saving........................................................................................................................................ 37
3.5.1. Sleep Mode................................................................................................................................. 37
3.5.1.1. UART Application Scenario...........................................................................................37
3.5.1.2. USB Application with USB Remote Wakeup Function............................................. 38
3.5.1.3. USB Application with USB Suspend/Resume and RI Function.............................. 39
3.5.1.4. USB Application Without USB Suspend Function.....................................................39
3.5.2. Airplane Mode.............................................................................................................................40
3.6. Power Supply........................................................................................................................................ 41
3.6.1. Power Supply Pins.....................................................................................................................41
3.6.2. Voltage Stability Requirements................................................................................................ 41
3.6.3. Reference Design for Power Supply.......................................................................................42
3.6.4. Monitor the Power Supply.........................................................................................................43
3.7. Power-on/off Scenarios....................................................................................................................... 43
3.7.1. Turn on with PWRKEY.............................................................................................................. 43
3.7.2. Turn off Module...........................................................................................................................45
3.7.2.1. Turn off with PWRKEY................................................................................................... 46
3.7.2.2. Turn off with AT Command............................................................................................ 46
3.8. Reset.......................................................................................................................................................46
3.9. (U)SIM Interface....................................................................................................................................48
3.10. USB Interface........................................................................................................................................ 51
3.11. UART Interfaces....................................................................................................................................52
3.12. PCM and I2C Interfaces...................................................................................................................... 54
3.13. SD Card Interface................................................................................................................................. 57