LTE Standard Module Series
EM05-G Hardware Design
EM05-G_Hardware_Design 45 / 69
4.4.3.
WWAN_LED#
WWAN_LED# is used to indicate the RF status of the module, and its sink current is up to 9 mA.
To reduce current consumption of the LED, a current-limited resistor must be placed in series with the
LED, as illustrated by the figure below. The LED is ON when the WWAN_LED# signal is at low level.
Module
WWAN_LED#
PMIC
10
VCC(Typ. 3.3 V)
R1
330
Ω
LED1
2, 4
70,72,74
VCC
Figure 22: WWAN_LED# Reference Circuit
The following table shows the RF status indicated by WWAN_LED#.
Table 16: RF Status Indications of WWAN_LED#
4.4.4.
WOWWAN#
The WOWWAN# is an open drain pin, which requires a pull-up resistor on the host. When a URC returns,
a 1s low level pulse will be outputted to wake up the host.
WWAN_LED# Logic Level
Description
Low Level (LED ON)
RF function is turned on
High Level (LED OFF)
RF function is turned off if any of the following occurs:
⚫
The (U)SIM card is not powered.
⚫
W_DISABLE1# is at low voltage level (airplane mode enabled).
⚫
AT+CFUN=4
(RF function disabled).