u-blox LARA-R2 series System Integration Manual page 95

Guidelines for single SIM card connection without detection
A removable SIM card placed in a SIM card holder has to be connected to the SIM card interface of LARA-R2
series modules as described in Figure 44, where the optional SIM detection feature is not implemented.
Follow these guidelines connecting the module to a SIM connector without 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.

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 the
SIM interface pins is 1 kV (HBM), so that, according to the EMC/ESD requirements of the custom application,
higher protection level can be required if the lines are externally accessible on the application device.

Limit capacitance and series resistance on each signal of the SIM interface (SIM_CLK, SIM_IO, SIM_RST), to
match the SIM interface specifications requirements (27.7 ns is the maximum allowed rise time on the
SIM_CLK line, 1.0 µs is the maximum allowed rise time on the SIM_IO and SIM_RST lines).
LARA-R2 series
V_INT
4
GPIO5
42
VSIM
41
SIM_IO
39
SIM_CLK
38
SIM_RST
40
Figure 44: Application circuit for the connection to a single removable SIM card, with SIM detection not 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, D2, D3, D4 Very Low Capacitance ESD Protection
J1 SIM Card Holder
6 positions, without card presence switch
Table 35: Example of components for the connection to a single removable SIM card, with SIM detection not implemented
UBX-16010573 - R02
TP
C1 C2 C3
Objective Specification
LARA-R2 series - System Integration Manual
C4 C5
D1 D2 D3 D4
Part Number - Manufacturer
GRM1555C1H470JA01 - Murata
GRM155R71C104KA01 - Murata
PESD0402-140 - Tyco Electronics
Various Manufacturers,
C707 10M006 136 2 - Amphenol
SIM CARD
HOLDER
VPP (C6)
VCC (C1)
C C C C
5 6 7 8
IO (C7)
C C C C
1 2 3 4
CLK (C3)
RST (C2)
SIM Card
Bottom View
GND (C5)
(contacts side)
J1
Design-in
Page 95 of 148