SARA-G450 - System integration manual
UBX-18046432 - R08
Design-in
Page 86 of 143
C1-Public
2.5.1.2
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
, where the optional SIM detection feature is not implemented (see the circuit
described in
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 contact 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 GND.
Provide a 1
µ
F bypass capacitor (e.g. Murata GRM155R70J105K) 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 33 pF (e.g. Murata GRM1555C1H330J) 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 1 pF) ESD protection (e.g. Tyco Electronics PESD0402-140)
on each externally accessible SIM line, close to each related pad of the SIM connector: the 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, a 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 regarding maximum allowed rise time on the lines.
scaling
SARA-G450
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 43: 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
33 pF capacitor ceramic C0G 0402 5% 50 V
GRM1555C1H330JA01 – Murata
C5
1
µ
F capacitor ceramic X7R 0402 10% 16 V
GRM155R70J105KA12 – Murata
D1, D2, D3, D4
Very low capacitance ESD protection
PESD0402-140 – Tyco Electronics
J1
SIM card holder
6 positions, without card presence switch
Generic manufacturer,
C707 10M006 136 2 – Amphenol
Table 28: Example of components for the connection to a single removable SIM card, with SIM detection not implemented
