Product Info

LTE Module Series
EC25 Hardware Design
EC25_Hardware_Design 69 / 112
3.20. USB_BOOT Interface
EC25 provides a USB_BOOT pin. Developers 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 24: 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 po int
Figure 31: Reference Circuit of USB_BOOT Interface
Pin Name Pin No. I/O Description Comment
USB_BOOT 115 DI
Force the module enter into
emergency download mode
1.8V power domain.
Active high.
It is recommended to
reserve test point.