Product Info

LTE Standard Module Series
EG95 Series Hardware Design
EG95_Series_Hardware_Design
57 / 99
Module
VDD_EXT
USB_BOOT
Test points
4.7K
Close to test points
TVS
Figure 28: Reference Circuit of USB_BOOT Interface
NOTE 1
VBAT
PWRKEY
≥ 500 ms
V
IL
≤ 0.5 V
About 100 ms
V
H
= 0.8 V
VDD_EXT
USB_BOOT
USB_BOOT can be pulled up to 1.8 V before
VDD_EXT Is powered up, and the module will
enter emerge ncy download mode wh en i t is
powered on.
RESET_N
Figure 29: Timing Sequence for Entering Emergency Download Mode
NOTES
1. Please make sure that VBAT is stable before pulling down PWRKEY pin. It is recommended that the
time between powering up VBAT and pulling down PWRKEY pin is no less than 30 ms.
2. When using MCU to control module to enter the emergency download mode, please follow the above
timing sequence. It is not recommended to pull up USB_BOOT to 1.8 V before powering up VBAT.
Connect the test points as shown in Figure 28 can manually force the module to enter download
mode.