User's Manual

Cinterion

EHS6-A Hardware Interface Overview Page 22 of 41

 EHS6-A_HIO_v02.770 2014-08-13

Confidential / Preliminary

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.

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).

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

[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.

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

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.

2.3 Sample Application