LISA-U2 series - System Integration Manual
UBX-13001118 - R19
Early Production Information
System description
Page 45 of 175
1.8
(U)SIM interface
High-speed SIM/ME interface is implemented as well as automatic detection of the required SIM supporting
voltage.
Both 1.8 V and 3 V SIM types are supported: activation and deactivation with automatic voltage switch from
1.8 V to 3 V is implemented, according to ISO-IEC 7816-3 specifications. The SIM driver supports the PPS
(Protocol and Parameter Selection) procedure for baud-rate selection, according to the values determined by the
SIM Card.
The
VSIM
supply output pin provides internal short circuit protection to limit start-up current and protect the
device in short circuit situations. No additional external short circuit protection is required.
Name
Description
Remarks
VSIM
SIM supply
1.80 V typical or 2.90 V typical
Automatically generated by the module
SIM_CLK
SIM clock
3.25 MHz clock frequency
SIM_IO
SIM data
Open drain, internal 4.7 k
pull-up resistor to
VSIM
SIM_RST
SIM reset
Table 21: SIM Interface pins
A low capacitance (i.e. less than 10 pF) ESD protection (e.g. Infineon ESD8V0L2B-03L or AVX USB0002RP)
must be placed near the SIM card holder on each line (
VSIM
,
SIM_IO
,
SIM_CLK
,
SIM_RST
). The SIM
interface pins ESD sensitivity rating is 1 kV (Human Body Model according to JESD22-A114F): higher
protection level is required if the lines are connected to an SIM card connector, since they are externally
accessible on the application board.
For more details about the general precautions for ESD immunity about SIM interface pins, see section
2.5.3.
The following SIM services are supported:
Abbreviated Dialing Numbers (ADN)
Fixed Dialing Numbers (FDN)
Last Dialed Numbers (LDN)
Service Dialing Numbers (SDN)
SIM Application Toolkit and USIM Application Toolkit (USAT) are supported.
The
GPIO5
pin is configured as an external interrupt to detect the SIM card mechanical / physical presence. The
pin is configured as input with an internal active pull-down enabled, and it can sense SIM card presence only if
properly connected to the mechanical switch of a SIM card holder as described in section 1.8.1.4 and 1.8.1.5:
Low logic level at
GPIO5
input pin is recognized as SIM card not present
High logic level at
GPIO5
input pin is recognized as SIM card present
The SIM card detection function provided by
GPIO5
pin is an optional feature that can be implemented / used or
not according to the application requirements. An Unsolicited Result Code (URC) can be generated each time
that there is a change of status (for more details see the “simind” value of the <descr> parameter of +CIND and
+CMER commands in the
u-blox AT Commands Manual
All the LISA-U2 series modules provide the additional function “SIM card hot insertion/removal” on the
GPIO5
pin, which can be enabled using the AT+UDCONF=50 command.
For more details on SIM detection function see section 1.12 as well as the
u-blox AT Commands Manual
+UGPIOC, +UDCONF=50 commands.
