Product Info

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design
4
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Contents
About the Document.................................................................................................................................................2
Contents....................................................................................................................................................................... 4
Table Index.................................................................................................................................................................. 7
Figure Index.................................................................................................................................................................9
1 Introduction...........................................................................................................................................................11
1.1. Safety Information......................................................................................................................................12
2 Product Concept..................................................................................................................................................13
2.1. General Description...................................................................................................................................13
2.2. Key Features.............................................................................................................................................. 14
2.3. Functional Diagram....................................................................................................................................17
2.4. Evaluation Board........................................................................................................................................17
3 Application Interfaces........................................................................................................................................ 18
3.1. General Description...................................................................................................................................18
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3.2. Pin Description........................................................................................................................................... 19
3.3. Operating Modes........................................................................................................................................28
3.4. Power Saving..............................................................................................................................................29
3.4.1. Sleep Mode......................................................................................................................................29
3.4.1.1. UART Application................................................................................................................ 29
3.4.1.2. USB Application with USB Remote Wakeup Function................................................. 30
3.4.1.3. USB Application with USB Suspend/Resume and RI Function.................................. 31
3.4.1.4. USB Application without USB Suspend Function..........................................................31
3.4.2. Airplane Mode................................................................................................................................. 32
3.5. Power Supply..............................................................................................................................................33
3.5.1. Power Supply Pins......................................................................................................................... 33
3.5.2. Decrease Voltage Drop................................................................................................................. 33
3.5.3. Reference Design for Power Supply...........................................................................................34
3.5.4. Monitor the Power Supply.............................................................................................................35
3.6. Turn on and off Scenarios........................................................................................................................ 35
3.6.1. Turn on Module Using the PWRKEY.......................................................................................... 35
3.6.2. Turn off Module...............................................................................................................................37
3.6.2.1. Turn off Module Using the PWRKEY Pin........................................................................37
3.6.2.2. Turn off Module Using AT Command...............................................................................38
3.7. Reset the Module.......................................................................................................................................38
3.8. (U)SIM Interface.........................................................................................................................................40
3.9. USB Interface............................................................................................................................................. 42
3.10. UART Interfaces.......................................................................................................................................44
3.11. PCM and I2C Interfaces......................................................................................................................... 46