LTE-A Module Series
EM121R-GL Hardware Design
EM121R-GL Hardware Design 32 / 80
Triggering the RESET# signal will lead to loss of all data in the modem and removal of system drivers. It
will also disconnect the modem from the network.
The module can be reset by pulling down the RESET# pin for 250
–600 ms. An open collector/drain driver
or a button can be used to control the RESET# pin.
Host
Module
RESET#
Reset
Logic
GPIO
67
1.8 V
Reset pulse
250
–
600 ms
40K
R3
100K
R2
1K
Q1
NPN
R1
1K
Figure 11: Reference Circuit for the RESET# with NPN Driver Circuit
Module
RESET#
67
250
–
600 ms
S1
TVS
33 pF
C1
Note:
The capacitor C1 is recommended to be less than 47 pF.
Reset
Logic
1.8 V
40K
R1
1K
Figure 12: Reference Circuit for the RESET# with a Button
The timing of reset scenario is illustrated in the following figure.
NOTE