Service Guide

LTE Standard Module Series
EG91_Series_Hardware_Design
44
/ 105
EG91 series module supports (U)SIM card hot-plug via USIM_PRESENCE (USIM1_PRESENCE/USIM2
_PRESENCE) pin, and both high and low level detection are supported. The function is disabled by
default, and see AT+QSIMDET in document [3] for more details.
The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector.
Module
USIM_VDD
USIM_GND
USIM_RST
USIM_CLK
USIM_DATA
USIM_PRESENCE
0R
0R
0R
VDD_EXT
51K
100 nF (U)SIM Card Connector
GND
GND
33 pF 33 pF 33 pF
VCC
RST
CLK
IO
VPP
GND
GND
USIM_VDD
15K
Figure 17: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector
USIM1_RST 44 DO (U)SIM1 card reset
USIM1_
PRESENCE
42 DI (U)SIM1 card insertion detection
1.8 V power domain.
If unused, keep it open.
USIM2_VDD 87 PO (U)SIM2 card power supply
Either 1.8 V or 3.0 V is
supported by the module
automatically.
If unused, keep it open.
USIM2_DATA 86 DIO (U)SIM2 card data
USIM2_CLK 84 DO (U)SIM2 card clock
USIM2_RST 85 DO (U)SIM2 card reset
USIM2_
PRESENCE
83 DI (U)SIM2 card insertion detection
1.8 V power domain.
If unused, keep it open.