u-blox LARA-R2 series System Integration Manual page 97

Guidelines for single SIM card connection with detection
A removable SIM card placed in a SIM card holder must be connected to the SIM card interface of LARA-R2
series modules as described in Figure 46, where the optional SIM card detection feature is implemented.
Follow these guidelines connecting the module to a SIM connector implementing SIM presence detection:

Connect the UICC / SIM contacts C1 (VCC) to the VSIM pin of the module.

Connect the UICC / SIM contact C7 (I/O) to the SIM_IO pin of the module.

Connect the UICC / SIM contact C3 (CLK) to the SIM_CLK pin of the module.

Connect the UICC / SIM contact C2 (RST) to the SIM_RST pin of the module.

Connect the UICC / SIM contact C5 (GND) to ground.

Connect one pin of the normally-open mechanical switch integrated in the SIM connector (e.g. the SW2 pin
as described in Figure 46) to the GPIO5 input pin of the module.

Connect the other pin of the normally-open mechanical switch integrated in the SIM connector (e.g. the
SW1 pin as described in Figure 46) to the V_INT 1.8 V supply output of the module by means of a strong
(e.g. 1 k) pull-up resistor, as the R1 resistor in Figure 46.

Provide a 100 nF bypass capacitor (e.g. Murata GRM155R71C104K) at the SIM supply line (VSIM), close to
the related pad of the SIM connector, to prevent digital noise.

Provide a bypass capacitor of about 22 pF to 47 pF (e.g. Murata GRM1555C1H470J) on each SIM line
(VSIM, SIM_CLK, SIM_IO, SIM_RST), very close to each related pad of the SIM connector, to prevent RF
coupling especially in case the RF antenna is placed closer than 10 - 30 cm from the SIM card holder.

Provide a low capacitance (i.e. less than 10 pF) ESD protection (e.g. Tyco Electronics PESD0402-140) on each
externally accessible SIM line, close to each related pad of the SIM connector: ESD sensitivity rating of SIM
interface pins is 1 kV (HBM according to JESD22-A114), so that, according to the EMC/ESD requirements of
the custom application, higher protection level can be required if the lines are externally accessible.

Limit capacitance and series resistance on each SIM signal to match the SIM specifications requirements
(27.7 ns = max allowed rise time on SIM_CLK, 1.0 µs = max allowed rise time on SIM_IO and SIM_RST).
LARA-R2 series
TP
V_INT
4
GPIO5
42
VSIM
41
SIM_IO
39
SIM_CLK
38
SIM_RST
40
Figure 46: Application circuit for the connection to a single removable SIM card, with SIM detection implemented
Reference Description
C1, C2, C3, C4 47 pF Capacitor Ceramic C0G 0402 5% 50 V
C5 100 nF Capacitor Ceramic X7R 0402 10% 16 V
D1 – D6 Very Low Capacitance ESD Protection
R1
1 k Resistor 0402 5% 0.1 W
R2
470 k Resistor 0402 5% 0.1 W
J1 SIM Card Holder
6 + 2 positions, with card presence switch
Table 37: Example of components for the connection to a single removable SIM card, with SIM detection implemented
UBX-16010573 - R02
R1
C1 C2 C3 C4 C5
D1 D2 D3 D4 D5 D6
Objective Specification
LARA-R2 series - System Integration Manual
SIM CARD
HOLDER
SW1
SW2
R2
VPP (C6)
VCC (C1)
IO (C7)
CLK (C3)
RST (C2)
Bottom View
GND (C5)
(contacts side)
J1
Part Number - Manufacturer
GRM1555C1H470JA01 - Murata
GRM155R71C104KA01 - Murata
PESD0402-140 - Tyco Electronics
RC0402JR-071KL - Yageo Phycomp
RC0402JR-07470KL- Yageo Phycomp
Various Manufacturers,
CCM03-3013LFT R102 - C&K Components
C C C C
5 6 7 8
C C C C
1 2 3 4
SIM Card
Design-in
Page 97 of 148