Specifications

Cinterion
®
ALAS66A Hardware Interface Overview
2.4 Sample Application
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 ALAS66A_HIO_v01.000a 2019-02-26
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2.4 Sample Application
Figure 13 shows a typical example of how to integrate an ALAS66A module with an application.
The PWR_IND line is an open collector that needs an external pull-up resistor which connects
to the voltage supply VCC µC of the microcontroller. Low state of the open collector pulls the
PWR_IND signal low and indicates that the ALAS66A module is active, high level notifies the
Power Down mode.
If the module is in Power Down mode avoid current flowing from any other source into the mod-
ule circuit, for example reverse current from high state external control lines. Therefore, the
controlling application must be designed to prevent reverse flow.
While developing SMT applications it is strongly recommended to provide test points
for certain signals, i.e., lines to and from the module - for debug and/or test purposes.
The SMT application should allow for an easy access to these signals. For details on
how to implement test points see [2].
The EMC measures are best practice recommendations. In fact, an adequate EMC strategy for
an individual application is very much determined by the overall layout and, especially, the po-
sition of components.
Some LGA pads are connected to clocks or high speed data streams that might interfere with
the module’s antenna. The RF receiver would then be blocked at certain frequencies (self in-
terference). The external application’s PCB tracks connected to these pads should therefore
be well shielded or kept away from the antenna. This applies especially to the USB and UICC/
SIM interfaces.
Depending on the micro controller used by an external application ALAS66A‘s digital input and
output lines may require level conversion.
Disclaimer:
No warranty, either stated or implied, is provided on the sample schematic diagram shown in
Figure 13 and the information detailed in this section. As functionality and compliance with na-
tional regulations depend to a great amount on the used electronic components and the indi-
vidual application layout manufacturers are required to ensure adequate design and operating
safeguards for their products using ALAS66A modules.