Smart LTE Module Series
SC650T Hardware Design
SC650T_Hardware_Design 51 / 131
TXS0104 EPWR
RXD_3.3V
CTS_3.3V
VCCA
Module
GND
GND
1.8V
VCCB
3.3V
DIN 1
ROUT3
ROUT 2
ROUT1
DIN4
DIN 3
DIN 2
DIN 5
FORCEON
3.3V
DOUT1
DOUT2
DOUT3
DOUT4
DOUT5
RIN3
RIN2
RIN1
VCC
GND
OE
SN65C 3238
DB-9
RTS
TXD
CTS
RXD
GND
RTS_3.3V
UART5_TXD
UART5_RTS
UART5_RXD
UART5_CTS
TXD_1.8V
RTS_1.8V
RXD_1.8V
CTS_1.8V
/FORCEOFF
/INVALID
R1OUTB
TXD_3.3V
Figure 14: RS232 Level Match Circuit (for UART5)
UART2, UART4 and UART6 are similar to UART5. Please refer to UART5 reference circuit design for
UART2, UART4 and UART6
’s.
3.11. (U)SIM Interfaces
SC650T provides two (U)SIM interfaces which both meet ETSI and IMT-2000 requirements. Dual SIM
Dual Standby is supported by default. Both 1.8V and 2.95V (U)SIM cards are supported, and the (U)SIM
interfaces are powered by the dedicated low dropout regulators from SC650T module.
Table 11: Pin Definition of (U)SIM Interfaces
Pin Name
Pin No. I/O
Description
Comment
USIM1_DET
145
DI
(U)SIM1 card 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.
USIM1_RST
144
DO
(U)SIM1 card reset signal
USIM1_CLK
143
DO
(U)SIM1 card clock signal
NOTE
