Gemalto M2M GmbH EHS6-A 사용자 설명서
Cinterion
®
EHS6-A Hardware Interface Overview
Page 22 of 41
EHS6-A_HIO_v02.770
2014-08-13
Confidential / Preliminary
2.3 Sample Application
22
2.3
Sample Application
Figure 6
shows a typical example of how to integrate a EHS6-A module with an application.
Usage of the various host interfaces depends on the desired features of the application.
The analog audio interface demonstrates the balanced connection of microphone and
earpiece. This solution is particularly well suited for internal transducers.
Because of the very low power consumption design, current flowing from any other source into
the module circuit must be avoided, for example reverse current from high state external
control lines. Therefore, the controlling application must be designed to prevent reverse current
flow. Otherwise there is the risk of undefined states of the module during startup and shutdown
or even of damaging the module.
control lines. Therefore, the controlling application must be designed to prevent reverse current
flow. Otherwise there is the risk of undefined states of the module during startup and shutdown
or even of damaging the module.
Because of the high RF field density inside the module, it cannot be guaranteed that no self
interference might occur, depending on frequency and the applications grounding concept.
The potential interferers may be minimized by placing small capacitors (47pF) at suspected
lines (e.g. RXD0, RXT0, VDDLP, and ON).
The potential interferers may be minimized by placing small capacitors (47pF) at suspected
lines (e.g. RXD0, RXT0, VDDLP, and ON).
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
The SMT application should allow for an easy access to these signals. For details on
how to implement test points see
[3]
.
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
position of components. For example, mounting the internal acoustic transducers directly on
the PCB eliminates the need to use the ferrite beads shown in the sample schematic.
position of components. For example, mounting the internal acoustic transducers directly on
the PCB eliminates the need to use the ferrite beads shown in the sample schematic.
Note: EHS6-A is not intended for use with cables longer than 3m.
Disclaimer
No warranty, either stated or implied, is provided on the sample schematic diagram shown in
No warranty, either stated or implied, is provided on the sample schematic diagram shown in
Figure 6
and the information detailed in this section. As functionality and compliance with
national regulations depend to a great amount on the used electronic components and the
individual application layout manufacturers are required to ensure adequate design and
operating safeguards for their products using EHS6-A modules.
individual application layout manufacturers are required to ensure adequate design and
operating safeguards for their products using EHS6-A modules.
2.3 Sample Application
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