Gemalto M2M GmbH PHS8-P User Manual
PHS8-P Hardware Interface Overview
7 Sample Application
37
PHS8-P_HIO_v01.000
Page 36 of 41
2011-11-10
Confidential / Released
7
Sample Application
shows a typical example of how to integrate an PHS8-P module with an application.
The audio interface demonstrates the balanced connection of microphone and earpiece. This
solution is particularly well suited for internal transducers.
solution is particularly well suited for internal transducers.
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 PHS8-P module is active, high level notifies the
Power-down mode.
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 PHS8-P 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. If an external level controller
is required, this can be done by using for example a 5V I/O tolerant buffer/driver like a
"74AVC4T245" with OE (Output Enable) controlled by PWR_IND.
ule circuit, for example reverse current from high state external control lines. Therefore, the
controlling application must be designed to prevent reverse flow. If an external level controller
is required, this can be done by using for example a 5V I/O tolerant buffer/driver like a
"74AVC4T245" with OE (Output Enable) controlled by PWR_IND.
While developing SMT applications it is strongly recommended to provide test points
for certain signals resp. 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
for certain signals resp. 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 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.
an individual application is very much determined by the overall layout and, especially, the po-
sition of components.
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
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 PHS8-P modules.
vidual application layout manufacturers are required to ensure adequate design and operating
safeguards for their products using PHS8-P modules.