Smart Module Series
SC262R_Series_Hardware_Design 48 / 115
SC262R series module supports (U)SIM card hot-plug via the USIM_DET pin. (This function is disabled
by default via software. To enable it, contact Quectel Technical Supports to change the 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
LDO5_1V8
100K
100 nF
(U)SIM Card Connector
22 pF
VCC
RST
CLK
IO
VPP
GND
USIM_ VDD
10K
Module
R1
R2
C1
22 pF
22 pF
C2
C3
C4
D1
22R
22R
R3
R4
R5
USIM_ VDD
NM
R6
TVS Array
Figure 16: Reference Circuit for (U)SIM Interface with an 8-pin (U)SIM Card Connector
If you do not need to use USIM_DET, keep this pin open. The following is a reference circuit for (U)SIM
interface with a 6-pin (U)SIM card connector.
Module
USIM_VDD
USIM_RST
USIM_CLK
USIM_DATA
22R
22R
22R
100 nF
(U)SIM card connector
22 pF
VCC
RST
CLK
IO
VPP
GND
10K
USIM_VDD
22 pF
22 pF
R1
C1
D1
R2
R3
R4
C2
C3
C4
USIM_ VDD
NM
R5
TVS Array
Figure 17: Reference Circuit for (U)SIM Interface with a 6-pin (U)SIM Card Connector
In order to ensure good performance and avoid damage of (U)SIM cards, follow the criteria listed below
during (U)SIM circuit design:
⚫
Place the (U)SIM card connector as close to the module as possible. Keep the trace length as short
as possible, at most 200 mm.
⚫
Keep (U)SIM card signals away from RF and VBAT traces.
⚫
Reserve a filter capacitor for USIM_VDD, and its maximum capacitance should not exceed 1
μF.
Additionally, place the capacitor near the
(U)SIM
card connector.
⚫
To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them with ground. USIM_RST also needs ground protection.
