Normally Open (U)Sim Card Connector - Quectel EM05-G Hardware Design

4.1.3. Normally Open (U)SIM Card Connector

With a normally open (U)SIM card connector, CD1 and CD2 of the connector are disconnected when
there is no (U)SIM card inserted. (U)SIM card detection by low level is applicable to this type of connector.
After executing AT+QSIMDET=1,0 to enable the (U)SIM hot-plug: when a (U)SIM card is inserted,
USIM_DET will change from high to low level; when the (U)SIM card is removed, USIM_DET will change
from low to high level.
⚫ When the (U)SIM is absent, CD1 is open from CD2 and USIM_DET is at high level.
⚫ When the (U)SIM is present, CD1 is pull down to ground and USIM_DET is at low level.
The following figure shows a reference design for (U)SIM interface with a normally open (U)SIM card
connector.
Module
USIM_VDD
USIM_RST
USIM_CLK
USIM_DET
USIM_DATA
GND
NOTE:
All these resistors, capacitors and TVS should be close to (U)SIM card connector in PCB layout.
Figure 16: Reference Circuit for Normally Open (U)SIM Card Connector
EM05-G_Hardware_Design
USIM_VDD
10-20k
22R
22R
22R
LTE Standard Module Series
EM05-G Hardware Design
(U)SIM Card
Connector
100 nF
VCC
RST
CLK
CD1
IO
GND
TVS
VPP
CD2
0 Ω
37 / 69