Quectel EG915U-EU Manual page 45

The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector.
Module
Figure 20: Reference Circuit of (U)SIM Interface with an 8-Pin (U)SIM Card Connector
A reference circuit for (U)SIM card interface with a 6-pin (U)SIM card connector is illustrated in the
following figure.
Module
Figure 21: Reference Circuit of a 6-Pin (U)SIM Card Connector
In order to enhance the reliability and availability of the (U)SIM card in applications, please follow the
criteria below in (U)SIM circuit design.
⚫
Keep placement of (U)SIM card connector as close to the module as possible. Keep the trace length
less than 200 mm as far as possible.
⚫
Keep (U)SIM card signals away from RF and VBAT traces.
⚫
Ensure USIM_VDD has a bypass capacitor less than 1 µF, and the capacitor should be close to the
(U)SIM card connector.
EG915U-EU_Hardware_Design
VDD_EXT USIM_VDD
51K
GND
USIM_VDD
0R
USIM_RST
USIM_CLK
0R
USIM_DET
USIM_DATA 0R
33 pF 33 pF 33 pF
USIM_VDD
15K
GND
USIM_VDD
0R
USIM_RST
USIM_CLK
0R
0R
USIM_DATA
33 pF 33 pF 33 pF
15K
100 nF
GND GND
100 nF
GND GND
LTE Standard Module Series
(U)SIM Card Connector
VCC GND
RST VPP
Switch
IO
CLK
GND
(U)SIM Card Connector
VCC GND
RST VPP
CLK IO
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