Users Manual

LTE Standard Module Series
EC25 Hardware Design
EC25_Hardware_Design
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In addition, RI behavior can be configured flexibly. The default behaviors of the RI is shown as below.
Table 23: Behaviors of RI
The RI behavior can be changed by AT+QCFG="urc/ri/ring" command. Please refer to document [2]
for details.
3.20. USB_BOOT Interface
EC25 provides a USB_BOOT pin. Customers can pull up USB_BOOT to 1.8V before VDD_EXT is
powered up, and the module will enter emergency download mode when it is 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.
State Response
Idle RI keeps at high level
URC RI outputs 120ms low pulse when a new URC returns
Pin Name Pin No. I/O Description Comment
USB_BOOT 115 DI
Force the module to enter emergency
download mode
1.8V power domain.
Active high.
It is recommended to
reserve test points.