Normally Closed (U)Sim Card Connector - Quectel RM520N-GL Hardware Design

Parameter
<enable>
<insert_level>
NOTE
1. Hot-plug function is invalid if the configured value of <insert_level> is inconsistent with hardware
design.
2. Hot-plug function takes effect after the module is restarted.
3. The underlined value is the default parameter value.
4. USIM1_DET hot-plug is enabled by default, while USIM2_DET hot-plug is disabled by default.

4.1.3. 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. Once
(U)SIM hot-plug is enabled by executing AT+QSIMDET=1,1, a (U)SIM card insertion will drive
USIM_DET from low to high level, and the removal of it will drive USIM_DET 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
USIM_VDD
USIM_RST
USIM_CLK
USIM_DET
USIM_DATA
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
RM520N-GL_Hardware_Design
Integer type. Enable or disable (U)SIM card detection.
0 Disable
1 Enable
Integer type. The level of (U)SIM detection pin when a (U)SIM card is inserted.
0 Low level
1 High level
USIM_VDD
10k-20k
22 Ω
22 Ω
22 Ω
GND
10pF
100 nF
TVS array
10 pF 10 pF
5G Module Series
(U)SIM Card
Connector
VCC VPP
RST
CLK
CD
IO
GND
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