Product Info
Table Of Contents
- About the Document
- Contents
- Table Index
- Figure Index
- 1 Introduction
- 2 Product Concept
- 3 Application Interfaces
- 3.1. General Description
- 3.2. Pin Assignment
- 3.3. Pin Description
- 3.4. Operating Modes
- 3.5. Power Saving
- 3.6. Power Supply
- 3.7. Power-on/off Scenarios
- 3.8. Reset the Module
- 3.9. (U)SIM Interfaces
- 3.10. USB Interface
- 3.11. UART Interfaces
- 3.12. PCM and I2C Interfaces
- 3.13. SPI Interface
- 3.14. Network Status Indication
- 3.15. STATUS
- 3.16. ADC Interface
- 3.17. Behaviors of RI
- 3.18. USB_BOOT Interface
- 4 GNSS Receiver
- 5 Antenna Interfaces
- 6 Electrical, Reliability and Radio Characteristics
- 7 Mechanical Dimensions
- 8 Storage, Manufacturing and Packaging
- 9 Appendix A References
- 10 Appendix B GPRS Coding Schemes
- 11 Appendix C GPRS Multi-slot Classes
- 12 Appendix D EDGE Modulation and Coding Schemes
LTE Standard Module Series
EG91 Hardware Design
EG91_Hardware_Design 36 / 93
1. In order to avoid damaging internal flash, please do not switch off the power supply when the
module works normally. Only after the module is shut down by PWRKEY or AT command, the
power supply can be cut off.
2. When turning off module with AT command, please keep PWRKEY at high level after the execution
of power-off command. Otherwise the module will be turned on again after successful turn-off.
3.8. Reset the Module
The RESET_N pin can be used to reset the module. The module can be reset by driving RESET_N to a
low level voltage for 150ms~460ms.
Table 8: Pin Definition of RESET_N
Pin Name Pin No. Description DC Characteristics Comment
RESET_N 17 Reset the module
V
IH
max=2.1V
V
IH
min=1.3V
V
IL
max=0.5V
The recommended circuit is similar to the PWRKEY control circuit. An open drain/collector driver or button
can be used to control the RESET_N.
Reset pulse
RESET_N
4.7K
47K
150ms~460ms
Figure 14: Reference Circuit of RESET_N by Using Driving Circuit
NOTES