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 33 / 93
3.7. Power-on/off Scenarios
3.7.1. Turn on Module Using the PWRKEY
The following table shows the pin definition of PWRKEY.
Table 7: Pin Definition of PWRKEY
Pin Name
Pin No. Description DC Characteristics Comment
PWRKEY 15 Turn on/off the module
V
IH
max=2.1V
V
IH
min=1.3V
V
IL
max=0.5V
The output voltage is 0.8V
because of the diode drop in
the Qualcomm chipset.
When EG91 is in power down mode, it can be turned on to normal mode by driving the PWRKEY pin to a
low level for at least 500ms. It is recommended to use an open drain/collector driver to control the PWRKEY.
After STATUS pin outputting a high level, PWRKEY pin can be released. A simple reference circuit is
illustrated in the following figure.
Turn on pulse
PWRKEY
4
.
7K
47
K
≥
5
00
ms
10nF
Figure 10: Turn on the Module Using Driving Circuit
Another way to control the PWRKEY is using a button directly. When pressing the key, electrostatic strike
may generate from the finger. Therefore, a TVS component is indispensable to be placed nearby the button
for ESD protection. A reference circuit is shown in the following figure.