Integration Manual

Table Of Contents
TOBY-L3 series - System Integration Manual
TSD-19090601 - R13 System Integration Manual Page 95 of 143
TOBY-L3 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 38: 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 32: Example of components for the connection to a single removable SIM card, with SIM detection implemented
2.5.2 Guidelines for SIM layout design
The layout of the SIM card interfaces lines (VSIM, SIM_CLK, SIM_IO, SIM_RST for the SIM interface) may
be critical if the SIM card is placed far away from the TOBY-L3 series modules or in close proximity to the
RF antenna: these two cases should be avoided or at least mitigated as described below.
In the first case, the long connection can cause the radiation of some harmonics of the digital data frequency
as any other digital interface. It is recommended to keep the traces short and avoid coupling with the RF
line or sensitive analog inputs.
In the second case, the same harmonics can be picked up and create self-interference that can reduce the
sensitivity of LTE/3G/2G receiver channels whose carrier frequency is coincidental with the harmonic
frequencies. It is strongly recommended to place the RF bypass capacitors suggested in Figure 36 near the
SIM connector.
In addition, since the SIM card is typically accessed by the end user, it can be subjected to ESD discharges.
Add adequate ESD protection as suggested to protect the module SIM pins near the SIM connector.
Limit the capacitance and series resistance on each SIM signal to match the SIM specifications. The
connections should always be kept as short as possible.
Avoid coupling with any sensitive analog circuit, since the SIM signals can cause the radiation of some
harmonics of the digital data frequency.