Smart LTE Module Series
SC650T Hardware Design
SC650T_Hardware_Design 52 / 131
USIM1_DATA
142
IO
(U)SIM1 card data signal
Pull up to USIM1_VDD with a 10K
resistor.
USIM1_VDD
141
PO
(U)SIM1 card power supply
Either 1.8V or 2.95V (U)SIM card
is supported.
USIM2_DET
256
DI
(U)SIM2 card insertion
detection
Active low.
Need external pull-up to 1.8V.
If unused, keep this pin open.
Disabled by default, and can be
enabled through software
configuration.
USIM2_RST
207
DO
(U)SIM2 card reset signal
USIM2_CLK
208
DO
(U)SIM2 card clock signal
USIM2_DATA
209
IO
(U)SIM2 card data signal
Pull-up to USIM2_VDD with a 10K
resistor.
USIM2_VDD
210
PO
(U)SIM2 card power supply
Either 1.8V or 2.95V (U)SIM card
is supported.
SC650T supports (U)SIM card hot-plug via the USIM_DET pin, which is disabled by default and can be
enabled through software configuration. A reference circuit for (U)SIM interface with an 8-pin (U)SIM card
connector is shown as below.
USIM_ VDD
USIM_RST
USIM_CLK
USIM_ DATA
USIM_DET
22R
LD05_1P8
100K
100nF
(U)SIM Card Connector
ESD
22pF
VCC
RST
CLK
IO
VPP
GND
USIM_ VDD
10K
Module
R1
R2
C1
22pF
22pF
C2
C3
C4
D1
22R
22R
R3
R4
R5
Figure 15: Reference Circuit for (U)SIM Interface with an 8-pin (U)SIM Card Connector
If there is no need to use USIM_DET, please keep it open. The following is a reference circuit for (U)SIM
interface with a 6-pin (U)SIM card connector.
