User's Manual

AWOX, S.A.
93 Place Pierre Duhem
34000 MONTPELLIER, France
Tel: [phone], Fax: [phone]
www.awox.com [e-mail]
T-0000-0005-V2.1: Digital Mozart II Module Page: 1 / 4
Technical Note
Digital Mozart II Module
1 Introduction
The original design of Mozart II includes everything an audio system designer needs in terms of digital
to analog conversion and analog signal management ready to feed to analog amplifiers or outputs.
Basically, ADC,DAC, FM tuner and all volume control and equalization are built-in.
Some applications do not make use of analog output (for instance, connecting the module to some
digital audio processor does not require analog) or will make use of their own converters for feature or
cost reasons. Therefore, Mozart II can be delivered as “digital only”, which means only the digital
stream is provided to the outside world.
The general considerations on Mozart II use can be found in the master documentation for the full-
fledged module. This document only describes the changes between the two versions. It is therefore
recommended to read the full-fledged version documentation before this one.
A reference schematic for Mozart II Digital implementation is provided.
2 Clocking
As in any digital audio system, clocking is an important point. Mozart II is using I2S 3-Wire protocol by
default and needs a Master Clock frequency to be provided on I2S_REF pin and equal to 11.2896MHz
or 12.288MHz. The internal module dividers provide the according I2S_LRCK, I2S_BCLK and the
I2S_DATA is latched conforming to I2S 16 bits per channel standard. Awox may carry on particular
studies upon customer request for specific unsupported sound peripherals.
3 DACs and amplifiers
3.1 SUPPORTED DACS
The reference DAC for use with Mozart II Digital is Wolfson Micro WM8711. This low-cost DAC allows
simple and easy construction of analog products using Mozart II Digital. It is the one that is used on
the Analog variant of the module and is therefore not part of the reference schematic for sake of
explanation; Mozart II Digital makes little sense versus the analog variant if the same peripherals are
used; the goal is to be able to use feature-rich peripherals for mid to high-end devices. Please contact
AwoX for more information.
3.2 AMPLIFIERS
The reference digital amplifier, Class-D, for use with Mozart II Digital is the Cirrus Logic CS4525. It
has provision for analog parts without adding external circuitry while still giving the benefit of the low-
cost and simplicity of Mozart II Digital.