Integration Manual

SARA-R4/N4 series - System Integration Manual

UBX-16029218 - R11 Design-in Page 97 of 157

100 nF Capacitor Ceramic X7R 0402 10% 16 V

GRM155R71C104KA01 - Murata

D1 – D6

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 28: 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 interface lines (VSIM, SIM_CLK, SIM_IO, SIM_RST may be critical if the SIM card

is placed far away from the SARA-R4/N4 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 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 receiver channels whose carrier frequency is coincidental with harmonic frequencies. It is

strongly recommended to place the RF bypass capacitors suggested in Figure 37 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 module SIM pins near the SIM connector.

Limit 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.