SARA-G3 and SARA-U2 series - System Integration Manual 
UBX-13000995 - R26    Design-in 
    Page 131 of 217 
Guidelines for single SIM card connection with detection 
  SIM card detection is not supported by SARA-G300-00S and SARA-G310-00S modules. 
 
An application circuit for the connection to a single removable SIM card placed in a SIM card holder is described 
in Figure 64, where the optional SIM card detection feature is implemented. 
Follow these guidelines connecting the module to a SIM connector implementing 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. 
  Connect one pin of the normally-open mechanical switch integrated in the SIM connector (as the SW2 pin in 
Figure 64) to the SIM_DET input pin, providing a weak pull-down resistor (e.g. 470 k, as R2 in Figure 64). 
  Connect the other pin of the normally-open mechanical switch integrated in the SIM connector (SW1 pin in 
Figure 64) to V_INT 1.8 V supply output by means of a strong pull-up resistor (e.g. 1 k, as R1 in Figure 64) 
  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: the ESD sensitivity rating of 
SIM  interface  pins  is  1  kV  (HBM  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.  
  Limit capacitance and series resistance on each SIM signal to match the requirements for the SIM interface 
(27.7 ns = max allowed rise time on SIM_CLK, 1.0 µs = max allowed rise time on SIM_IO and SIM_RST). 
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
SW1
SW2
D1 D2 D3 D4 D5 D6
R2
R1
C
8
C
4
TP
 
Figure 64: Application circuit for the connection to a single removable SIM card, with SIM detection implemented 
Part Number - Manufacturer 
47 pF Capacitor Ceramic C0G 0402 5% 50 V 
GRM1555C1H470JA01 - Murata 
100 nF Capacitor Ceramic X7R 0402 10% 16 V 
GRM155R71C104KA01 - Murata 
Very Low Capacitance ESD Protection 
PESD0402-140 - Tyco Electronics  
1 k Resistor 0402 5% 0.1 W 
RC0402JR-071KL - Yageo Phycomp 
470 k Resistor 0402 5% 0.1 W 
RC0402JR-07470KL- Yageo Phycomp 
SIM Card Holder 
6 + 2 positions, with card presence switch 
Various Manufacturers, 
CCM03-3013LFT R102 - C&K Components 
Table 42: Example of components for the connection to a single removable SIM card, with SIM detection implemented