TOBY-L4 series - System Integration Manual
UBX-16024839 - R04
Design-in
Page 82 of 143
Guidelines for single SIM card connection with detection
If the optional SIM card detection feature is required by the application, then a removable SIM card placed in a
SIM card holder must be connected to the SIM0 interface of TOBY-L4 series modules as illustrated in Figure 39:
Follow these guidelines to connect the module to a SIM connector implementing 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 ground.
Connect one pin of the normally-open mechanical switch integrated in the SIM connector (e.g. the SW2 pin
as illustrated in Figure 39) 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 illustrated in Figure 39) 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 39.
Provide a weak (e.g. 470 k
) pull-down resistor at the SIM detection line, as the R2 resistor in Figure 39.
Provide a 100 nF bypass capacitor (e.g. Murata GRM155R71C104K) at the SIM supply line, 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, very
close to each related pad of the SIM connector, to prevent RF coupling especially when the RF antenna is
placed closer than 10 - 30 cm from the SIM card holder.
Provide a very low capacitance (i.e. less than 10 pF) ESD protection (e.g. Tyco 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,
a higher protection level can be required if the lines are externally accessible on the application device.
Limit the capacitance and series resistance on each SIM signal to match the SIM requirements (20.5 ns is the
maximum rise time on the clock line, 1.0 µs is the maximum rise time on the data and reset lines).
TOBY-L4 series
5
V_INT
60
GPIO5
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
SW1
SW2
D1 D2 D3 D4 D5 D6
R2
R1
C
8
C
4
TP
59
VSIM
57
SIM_IO
56
SIM_CLK
58
SIM_RST
Figure 39: Application circuit for the connection to a single removable SIM card, with SIM detection 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, … , D6
Very Low Capacitance ESD Protection
PESD0402-140 - Tyco Electronics
R1
1 k
Resistor 0402 5% 0.1 W
RC0402JR-071KL - Yageo Phycomp
R2
470 k
Resistor 0402 5% 0.1 W
RC0402JR-07470KL- Yageo Phycomp
J1
SIM Card Holder, 6 + 2 p, with card presence switch
Various manufacturers, as CCM03-3013LFT R102 - C&K
Table 30: Example of components for the connection to a single removable SIM card, with SIM detection implemented