LTE-A Module Series
EM12-G Hardware Design
EM12-G_Hardware_Design 30 / 62
Module
USIM_VDD
USIM_RESET
USIM_CLK
USIM_DATA
USIM_DET
22R
22R
22R
100nF
(U)SIM Card Connector
GND
GND
33pF
33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
15K
GND
CD
SW
Figure 13: Reference Circuit of Normally Short-Circuited (U)SIM Card Connector
Normally Short-Circuited (U)SIM Card Connector:
When the (U)SIM is absent, CD is short-circuited to SW and USIM_DET is at low level.
When the (U)SIM is inserted, CD is open to SW and USIM_DET is at high level.
The following figure shows a reference design of (U)SIM interface with normally open (U)SIM card
connector.
Module
USIM_VDD
USIM_RESET
USIM_CLK
USIM_DATA
USIM_DET
22R
22R
22R
100nF
(U)SIM Card Connector
GND
33pF
33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
15K
GND
CD
1.8V
4.7K
33K
SW
Figure 14: Reference Circuit of Normally Open (U)SIM Card Connector
Normally Open (U)SIM Card Connector:
When the (U)SIM is absent, CD is open to SW and USIM_DET is at low level.
When the (U)SIM is inserted, CD is short-circuited to SW and USIM_DET is at high level.