User's Manual

T-0000-0004-V2.1: Using Mozart II
T-0000-0004-V2.1: Using Mozart II Page: 6 / 24
For complete equipment, Line Outputs can be used as well. In this kind of structure, the Line Outputs
will often be fixed-volume:
Finally, “accessory” devices will not have internal speakers (but they can still use headphones !).
Internal amplification is removed in this case and the amplifier feed is connected directly to output
jacks.
4.6 USING LINE INPUT
The Line In terminals can be used to grab audio from an external source, such as an MP3 player, CD
player, cassette deck, iPod, etc. The audio analog is routed through the internal DAC therefore sound
control for it is available. The Line Input and the FM tuner mode are exclusive.
If no Line In is requested, then the FM Out should be tied directly to Line In.
4.7 POWERING CONSIDERATIONS
The module requires 3.3v power rail. The 3.3v is the main power supply and, as all digital power
supplies, is highly subject to digital commutation bursts and high current flows. It is therefore important
that this line presents low impedance, is well decoupled, and not too long from the power supply
location.
There is no recommended scheme for powering – it really depends on the kind of peripherals used in
the rest of the device. If the main PSU is +5V (this will be the case if the device does not have
amplification, such as a Hi-Fi accessory) then it makes sense to use linear regulation, while DC/DC
scheme could be preferred if the main PSU is +12V. In case of DC/DC use, EMC concerns arise.