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GM47/GM48 INTEGRATOR’S MANUAL
60
LZT 123 7263 R1C
SIM voltage levels, as shown in the following table, are dependent on
the type of SIM card detected by the module.
2.9.1 SIM Detection - SIMPRESENCE
SIMPRESENCE is used to determine whether a SIM card has been
inserted into or removed from the SIM card holder. You should
normally wire it to the “card inserted switch” of the SIM card holder,
but different implementations are possible.
When left open, an internal pull-up resistor maintains the signal high
and means “SIM card missing” to the module. When pulled low the
module assumes a SIM card is inserted.
SIMPRESENCE is a Digital 2.75 CMOS input with the following
electrical characteristics.
Note! To meet regulatory approvals SIMPRESENCE must be implemented.
Signal Parameter Mode Min. Typ. Max. Unit
SIMVCC SIM supply voltage
3V 2.7 3.0 3.3 V
5V 4.5 5.0 5.5 V
SIMDAT
High Level Input
voltage (V
IH
)
3V 2.1 3.0 V
5V 3.5 5.0 V
SIMDAT
Low Level Input
voltage (V
IL
)
3V 0 0.9 V
5V 0 1.5 V
SIMDAT
High Level Output
voltage (V
OH
)
3V 2.7 3.0 V
5V 4.7 5.0 V
SIMDAT
Low Level Output
voltage (V
OL
)
3V 0 0.2 V
5V 0 0.2 V
SIMCLK
SIMRST
High Level Output
voltage (V
OH
)
3V 2.4 3.0 V
5V 4.4 5.0 V
SIMCLK
SIMRST
Low Level Output
voltage (V
OL
)
3V 0 0.35 V
5V 0 0.3 V
Parameter Min. Typ. Max. Units
Pull-up resistance (at 2.75 V) 100 kΩ
Low Level Input voltage (SIM inserted) 0.80 V
High Level Input voltage (SIM missing) >1.93 2.75 V