Wwan_Led# Signal - Quectel LTE-A Module Series Hardware Design

A simple level shifter based on diodes is used on W_DISABLE1# pin and W_DISABLE2# pin which are
pulled up to a 1.8 V voltage in the module, as shown in the following figure. So, the control signals (GPIO)
of the host device could be a 1.8 V or 3.3 V voltage level and pull-up resistor is not needed on the host
side. These two signals are active low, and a reference circuit is shown below.
Host
GPIO
GPIO
Note:
Host's GPIO could be a 1.8 V or 3.3 V voltage level.
Figure 27: W_DISABLE1# and W_DISABLE2# Reference Circuit

3.10.3. WWAN_LED# Signal

The WWAN_LED# signal is used to indicate RF status of the modules, and its typical current
consumption is up to 10 mA.
In order to reduce the current consumption of the LED, a resistor must be placed in series with the LED,
as illustrated in the figure below. The LED is ON when the WWAN_LED# signal is at a low voltage level.
Host
GPIO
Note: This VCC could be the power supply of the module.
Figure 28: WWAN_LED# Signal Reference Circuit
EM120R-GL&EM160R-GL_Hardware_Design
EM120R-GL&EM160R-GL Hardware Design
VCC_IO_HOST
R1 R2
10K 10K
W_DISABLE2#
W_DISABLE1#
VCC
R1
200Ω
LED
WWAN_LED#
LTE-A Module Series
Module
VDD 1.8 V
R3 R4
10K 10K
26
BB
8
Module
10
PMU
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