LTE Standard Module Series
EG21-G Mini PCIe Hardware Design
EG21-G_Mini_PCIe_Hardware_Design 29 / 54
V
IL
≤0.5V
V
IH
≥2.3V
VCC_3V3
≥150ms
Resetting
Module
Status
Running
PERST#
Restart
≤460ms
Figure 12: Timing of Resetting Module
3.8.5. LED_WWAN# Signal
The LED_WWAN# signal of EG21-G Mini PCIe is used to indicate the network status of the module, and
can absorb the current up to 40mA. According to the following circuit, in order to reduce the current of the
LED, a resistor must be placed in series with the LED. The LED is emitting light when the LED_WWAN#
output signal is active low.
The LED is emitting light when the LED_WWAN# output signal is low.
LED_WWAN#
VCC
R
Figure 13: LED_WWAN# Signal Reference Circuit Diagram
There are two indication modes for LED_WWAN# signal to indicate network status, which can be
switched through following AT commands:
AT+QCFG="ledmode",0
(Default setting)
AT+QCFG="ledmode",2
The following tables show the detailed network status indications of the LED_WWAN# signal.
