LTE Standard Module Series
EG25-GL_Hardware_Design 41 / 96
Module
USIM_VDD
USIM_GND
USIM_RST
USIM_CLK
USIM_DATA
USIM_DET
0R
0R
0R
VDD_EXT
51K
100 nF
GND
GND
33 pF 33 pF 33 pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
15K
(U)SIM Card Connector
TVS array
Figure 17: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, keep USIM_DET unconnected. A reference circuit of
(U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure.
Module
USIM_VDD
USIM_GND
USIM_RST
USIM_CLK
USIM_DATA
0R
0R
0R
GND
VCC
RST
CLK
IO
VPP
GND
GND
15K
USIM_VDD
(U)SIM Card Connector
33 pF 33 pF 33 pF
100 nF
TVS array
Figure 18: Reference Circuit of (U)SIM Interface with a 6-pin (U)SIM Card Connector
In order to enhance the reliability and availability of the (U)SIM card in your applications, please follow the
criteria below in (U)SIM circuit design:
⚫
Place the (U)SIM card connector as close to the module as possible. Keep the trace length as short
as possible, at most 200 mm.
⚫
Keep (U)SIM card signal traces away from RF and power supply traces.
⚫
Make sure the bypass capacitor between USIM_VDD and USIM_GND less than 1
μF, and place it as
close to (U)SIM card connector as possible. If the ground is complete on your PCB, USIM_GND can