Product Info

Smart LTE Module Series
SC66 Hardware Design
SC66_Hardware_Design 61 / 139
SC66 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 below.
USIM_ VDD
USIM_ RST
USIM_CLK
USIM_ DATA
USIM_DET
22R
100K
100nF
(U)SIM Card Connector
ESD
22pF
VCC
RST
CLK
IO
VPP
GND
USIM_ VDD
10K
Module
R1
R2
C1
22pF22pF
C2 C3 C4
D1
22R
22R
R3
R4
R5
LDO13A_1P8
Figure 19: 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.
Cannot be multiplexed into a
general-purpose GPIO.
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 to1.8V.
If unused, keep this pin open.
USIM2_RST 207 DO (U)SIM2 card reset signal
Cannot be multiplexed into a
general-purpose GPIO.
USIM2_CLK 208 DO (U)SIM2 card clock signal
Cannot be multiplexed into a
general-purpose GPIO.
USIM2_DATA 209 IO (U)SIM2 card data signal
Pull up to USIM2 with a 10KΩ
resistor.
Cannot be multiplexed into a
general-purpose GPIO.
USIM2_VDD 210 PO (U)SIM2 card power supply
Either 1.8V or 2.95V (U)SIM card
is supported.