User's Guide

LE920A4 HW User Guide Application Guide
Doc#: 1VV0301261 SIM Interface
Rev. 4.7.1 Page 104 of 124 2019-11-21
SIM Interface
This section presents the recommended schematics for the design of SIM interfaces on
the application boards. The module supports two external SIM interfaces.
11.3.1. SIM Schematic Example
Figure 29 illustrates in particular how to design the application side and which values to
assign the components.
Figure 29: SIM Schematics
NOTE:
The resistor value on SIMIO pulled up to SIMVCC must be defined to be
compliant with the 3GPP specification for USIM electrical testing.
The module contains an internal pull-up resistor of 10KΩ on SIMIO.
However, the un-mounted option in the application design can be
recommended to tune R1 if necessary.
The value of the C1 capacitor to be applied with the module is 100 nF.