Product Info

Smart Module Series
SC606T Series Hardware Design
SC606T_Series_Hardware_Design 49 / 116
an 8-pin (U)SIM card connector is shown below.
USIM_VDD
USIM_RST
USIM_CLK
USIM_ DATA
USIM_DET
22R
LD05_1P8
100K
100 nF
(U)SIM Card Connector
ESD
22 pF
VCC
RST
CLK
IO
VPP
GND
USIM_VDD
10K
Module
R1
R2
C1
22 pF22 pF
C2 C3 C4
D1
22R
22R
R3
R4
R5
Figure 15: Reference Design for (U)SIM Interface with an 8-pin (U)SIM Card Connector
If there is no need to use USIM_DET, keep it open. The following is a reference design for the (U)SIM
interfaces connected with a 6-pin (U)SIM card connector.
Module
USIM_VDD
USIM_RST
USIM_CLK
USIM_ DATA
22R
22R
22R
100 nF
ESD
22 pF
VCC
RST
CLK IO
VPP
GND
10K
USIM_VDD
22pF
22 pF
R1
C1
D1
R2
R3
R4
C2 C3 C4
USIM_DET
(U)SIM Card Connector
Figure 16: Reference Design for (U)SIM Interface with a 6-pin (U)SIM Card Connector
To ensure good performance and avoid damage of (U)SIM cards, please follow these principles in your
design:
⚫ Place the (U)SIM card connector as close to the module as possible. Keep the (U)SIM trace length
as less than 200 mm as possible.
⚫ Keep (U)SIM card signal traces away from RF and VBAT traces.
⚫ Reserve a filter capacitor for USIM_VDD, and keep the capacitance of the capacitor within 1 μF.
Place the capacitor near to the (U)SIM card.
⚫ To avoid cross-talk between USIM_DATA and USIM_CLK traces, keep them away from each other
and shield them with the ground. USIM_RST also needs such ground protection.
⚫ To offer good ESD protection, add a TVS diode array with a parasitic capacitance within 50 pF. The
22 Ω resistors should be added in series between the module and (U)SIM card so as to suppress