Quectel EM05-G - Normally Closed (U)SIM Card Connector

LTE Standard Module Series
EM05-G Hardware Design
EM05-G_Hardware_Design 36 / 69
1)
This pin is pulled LOW by default, and will be internally pulled up to 1.8 V by software configuration only
when (U)SIM hot-plug is enabled by AT+QSIMDET.
4.1.2. Normally Closed (U)SIM Card Connector
With a normally closed (U)SIM card connector, USIM_DET pin is shorted to ground when there is no
(U)SIM card inserted. (U)SIM card detection by high level is applicable to this type of connector. After
executing AT+QSIMDET=1,1 to enable the (U)SIM hot-plug: when a (U)SIM card is inserted, USIM_DET
will change from low to high level; when the (U)SIM card is removed, USIM_DET will change from high to
low level.
⚫ When the (U)SIM is absent, CD is shorted to ground and USIM_DET is at low level.
⚫ When the (U)SIM is present, CD is open from ground and USIM_DET is at high level.
The following figure shows a reference design for (U)SIM interface with a normally closed (U)SIM card
connector.
Module (U)SIM Card
Connector
USIM_DET
USIM_DATA
USIM_CLK
RST
CLK
CD
IO
USIM_VDD
USIM_VDD
USIM_RST
VCC
GND
VPP
GND
TVS
10-20k
22R
22R
22R
33 pF 33 pF
33 pF
100 nF
NOTE:
All these resistors, capacitors and TVS should be close to (U)SIM card connector in PCB layout.
Figure 15: Reference Circuit for Normally Closed (U)SIM Card Connector
42
USIM2_DATA
DIO, PU
(U)SIM2 card data
USIM2_VDD
1.8/3.0 V
44
USIM2_CLK
DO, PD
(U)SIM2 card clock
USIM2_VDD
1.8/3.0 V
46
USIM2_RST
DO, PD
(U)SIM2 card reset
USIM2_VDD
1.8/3.0 V
40
USIM2_DET
1)
DI, PU
(U)SIM2 card hot-plug detect
1.8 V
NOTE