Quectel RG520N-AT - Page 50

5G Module Series
RG520N-AT_Hardware_Design 49 / 109
The module supports (U)SIM card hot-plug via the USIM_DET pin, and both high level and low level
detection is supported. The function is disabled by default and can be configured via AT+QSIMDET. See
document [3] for more details about the command.
The following figure illustrates a reference design for (U)SIM card interface with an 8-pin (U)SIM card
connector.
Module
USIM_VDD
USIM_RST
USIM_CLK
USIM_DATA
USIM_DET
0R
0R
0R
VDD_EXT
100K
100 nF
(U)SIM Card Connector
GND
GND
10 pF 10 pF 10 pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
20K
10 pF
TVS Array
Figure 20: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, keep USIM_DET unconnected. A reference circuit for
(U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following figure.
USIM1_DET
249
DI
(U)SIM1 card hot-plug
detect
1.8 V power domain.
If unused, keep it open.
USIM2_VDD
250
PO
(U)SIM2 card power
supply
Either 1.8 V or 2.95 V is
supported and can be
identified automatically by
the module.
USIM2_DATA
251
DIO
(U)SIM2 card data
USIM2_CLK
253
DO
(U)SIM2 card clock
USIM2_RST
254
DO
(U)SIM2 card reset
USIM2_DET
252
DI
(U)SIM2 card hot-plug
detect
1.8 V power domain.
If unused, keep it open.