User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R08 Objective Specification Design-in
Page 109 of 188
Guidelines for single SIM card connection without detection
An application circuit for the connection to a single removable SIM card placed in a SIM card holder is described
in Figure 54, where the optional SIM detection feature is not implemented (see the circuit described in Figure 56
if the SIM detection feature is required).
Follow these guidelines connecting the module to a SIM connector without SIM presence detection:
 Connect the UICC / SIM contacts C1 (VCC) and C6 (VPP) 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 (Human Body Model 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 on the application device
 Limit capacitance and series resistance on each SIM signal (SIM_CLK, SIM_IO, SIM_RST) to match the
requirements for the SIM interface (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)
SARA-G3 / SARA-U2
41
VSIM
39
SIM_IO
38
SIM_CLK
40
SIM_RST
4
V_INT
42
SIM_DET
SIM CARD
HOLDER
C
5
C
6
C
7
C
1
C
2
C
3
SIM Card
Bottom View
(contacts side)
C1
VPP (C6)
VCC (C1)
IO (C7)
CLK (C3)
RST (C2)
GND (C5)
C2 C3 C5
J1
C4
D1 D2 D3 D4
C
8
C
4
TP
Figure 54: Application circuit for the connection to a single removable SIM card, with SIM detection not implemented
Reference
Description
Part Number - Manufacturer
C1, C2, C3, C4
47 pF Capacitor Ceramic C0G 0402 5% 50 V
GRM1555C1H470JA01 - Murata
C5
100 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C104KA01 - Murata
D1, D2, D3, D4
Very Low Capacitance ESD Protection
PESD0402-140 - Tyco Electronics
J1
SIM Card Holder
6 positions, without card presence switch
Various Manufacturers,
C707 10M006 136 2 - Amphenol
Table 27: Example of components for the connection to a single removable SIM card, with SIM detection not implemented