Product Info

Smart LTE Module Series
SC20 Hardware Design
SC20_Hardware_Design 47 / 130
3.11. (U)SIM Interfaces
SC20 provides 2 (U)SIM interfaces which circuitry meet ETSI and IMT-2000 requirements. Dual SIM Card
Dual Standby is supported by default. Both 1.8V and 2.95V (U)SIM cards are supported, and the (U)SIM
card interfaces are powered by the internal power supply of SC20 module.
Table 13: Pin Definition of (U)SIM Interfaces
SC20 supports (U)SIM card hot-plug via the USIM_DETECT pin. A reference circuit for (U)SIM interface
with an 8-pin (U)SIM card connector is shown below.
Pin Name
Pin No
I/O
Description
Comment
USIM2_DETECT
17
DI
(U)SIM2 card hot-plug detection
Active Low. External pull-up
resistor is required.
If unused, keep this pin open.
USIM2_RST
18
DO
(U)SIM2 card reset signal
USIM2_CLK
19
DO
(U)SIM2 card clock signal
USIM2_DATA
20
IO
(U)SIM2 card data signal
Pull-up to USIM2_VDD with a
10K resistor.
USIM2_VDD
21
PO
(U)SIM2 card power supply
Either 1.8V or 2.95V (U)SIM
card is supported by the
module automatically.
USIM1_DETECT
22
DI
(U)SIM1 card hot-plug
detection
Active low. External pull-up
resistor is required.
If unused, keep this pin open.
USIM1_RST
23
DO
(U)SIM1 card reset signal
USIM1_CLK
24
DO
(U)SIM1 card clock signal
USIM1_DATA
25
IO
(U)SIM1 card data signal
Pull-up to USIM1_VDD with a
10K resistor.
USIM1_VDD
26
PO
(U)SIM1 card power supply
Either 1.8V or 2.95V (U)SIM
card is supported by the
module automatically.