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 52 / 93
V
IL
≤
0.5V
V
H
=0.8V
VBAT
PWRKEY
≥
500ms
RESET_N
NOTE
VDD_EXT
About 100ms
USB_BOOT
Setting USB_BOOT to high level between VBAT rising
on and VDD_EXT rising on can let the module enter
into emergency download mode.
Figure 29: Timing Sequence for Entering into Emergency Download Mode
1. Please make sure that VBAT is stable before pulling down PWRKEY pin. The time between them
is no less than 30ms.
2. When using MCU to control module to enter into the emergency download mode, follow the above
timing sequence. It is not recommended to pull up USB_BOOT to 1.8V before powering up the
VBAT. Short the test points as shown in Figure 28 can manually force the module to enter into
download mode.
NOTES