User's Manual

H380 M.2 Series Module Hardware User Manual page
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2）Insert SIM card, pin 7 and pin 8 disconnect.
5.5.2.2 Normally Open SIM Circuit Design
Reference Design:
Figure 5- 8 Normally Open SIM Connector Reference Design
Normally Open SIM Connector:
1）Pull out SIM card, pin 7 and pin 8 disconnect.
2）Inset SIM card, pin 7 and pin 8 short.
Note:

For improving EMC performance, SIM card connector should be closed to module
 Filtering capacitor should be closed to SIM card pin
 The interface need ESD protection, ESD should be closed to SIM card pin

USIM_DATA is already pulled up(4.7K ohms) inside the module
SIM_DETECT support SIM hot plug, high level activated default (detect level can be changed by AT
command). If high level is detected, it means SIM card is inserted.
5.5.3 USIM Design Notice
The SIM interface and signals design is extremely important.
There are several design guidelines that must be followed:

The signals of the SIM card layout should be away from any possible EMI noise, such as RF antenna
and digital switching signals.
 To ensure signal integrity, the length between SIM interface signals and module should not exceed
100 mm
 To avoid crosstalk between USIM_CLK and USIM_IO, it is recommended to route them separately on
the application board, and preferably isolated by Ground layer.