User's Manual

Cinterion
®
ELS61-AUS Hardware Interface Description
3.7 Blocking against RF on Interface Lines
73
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ELS61-AUS_HID_v00.031 2016-06-03
Confidential / Preliminary
Page 71 of 102
3.7 Blocking against RF on Interface Lines
To reduce EMI issues there are serial resistors, or capacitors to GND, implemented on the
module for the ignition, emergency restart, and SIM interface lines (cp. Section 2.3). However,
all other signal lines have no EMI measures on the module and there are no blocking measures
at the module’s interface to an external application.
Dependent on the specific application design, it might be useful to implement further EMI mea-
sures on some signal lines at the interface between module and application. These measures
are described below.
There are five possible variants of EMI measures (A-E) that may be implemented between
module and external application depending on the signal line (see Figure 40 and Table 16). Pay
attention not to exceed the maximum input voltages and prevent voltage overshots if using in-
ductive EMC measures.
The maximum value of the serial resistor should be lower than 1k
Ω on the signal line. The max-
imum value of the capacitor should be lower than 50pF on the signal line. Please observe the
electrical specification of the module‘s SMT application interface and the external application‘s
interface.
Figure 40: EMI circuits
Note: In case the application uses an internal RF antenna that is implemented close to the
ELS61-AUS module, Gemalto strongly recommends sufficient EMI measures, e.g. of type B or
C, for each digital input or output.
C
GND
SMT
R
Application
EMI measures A
SMT
R
Application
EMI measures C
C
GND
SMT
L
Application
EMI measures E
C
GND
SMT
Application
EMI measures B
SMT
L
Application
EMI measures D