Quectel LTE Standard Module Series User Manual

LTE Module Series
EG21-G Hardware Design
EG21-G_Hardware_Design 52 / 100
EG21-G provides a USB_BOOT pin. Customers can pull up USB_BOOT to VDD_EXT before powering
on the module, thus the module will enter into emergency download mode when powered on. In this mode,
the module supports firmware upgrade over USB interface.
Table 22: Pin Definition of USB_BOOT Interface
Pin Name
Pin No.
I/O
Description
Comment
USB_BOOT
115
DI
Force the module to enter into
emergency download mode
1.8V power domain.
Active high.
It is recommended to reserve test
point.
The following figure shows a reference circuit of USB_BOOT interface.
Module
USB_BOOT
VDD_EXT
4.7K
Test point
TVS
Close to test point
Figure 28: Reference Circuit of USB_BOOT Interface
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.

Quectel LTE Standard Module Series Specifications

General

Brand	Quectel
Model	LTE Standard Module Series
Category	Wireless modules
Language	English