Quectel EG915U Series - USBBOOT Interface

LTE Standard Module Series
EG915U_Series_Hardware_Design 42 / 81
layer and ground planes above and below.
⚫ Pay attention to the selection of the ESD component on the USB data line. Its stray capacitance
should not exceed 2 pF and should be placed as close as possible to the USB connector.
4.3. USB_BOOT Interface
The module provides a USB_BOOT pin. You can pull up USB_BOOT to VDD_EXT before power-up and
the module will enter download mode when it is turned on. In this mode, the module supports firmware
upgrade over USB interface.
Table 12: Pin Definition of USB_BOOT Interface
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
GND
2
1
3
Figure 19: Reference Circuit of USB_BOOT Interface
Pin Name
Pin No.
I/O
Description
Comment
USB_BOOT
75
DI
Control pin for module to enter
download mode
1.8 V power domain.
Active high.
A circuit that enables the module to
enter the download mode must be
reserved.