Datasheet

MAX9880A
Low-Power, High-Performance
Dual I
2
S Stereo Audio Codec
62 ______________________________________________________________________________________
ACKNOWLEDGE FROM MAX9880A
1 BYTE
AUTOINCREMENT INTERNAL
REGISTER ADDRESS POINTER
ACKNOWLEDGE FROM MAX9880A
AAA
NOT ACKNOWLEDGE FROM MASTER
A
P
0
ACKNOWLEDGE FROM MAX9880A
R/W
S
R/W
REPEATED START
Sr 1SLAVE ADDRESS REGISTER ADDRESS SLAVE ADDRESS DATA BYTE
Figure 20. Reading n Bytes of Data
SEQUENCE DESCRIPTION REGISTERS
1 SHDN = 0 0x27
2 Configure clocks 0x05, 0x06, 0x07, 0x0B, 0x0C
3 Configure digital audio interface 0x08, 0x09, 0x0A, 0x0D, 0x0E, 0x0F
Table 27. Clock Initialization (Perform Before Any Playback or Record Setup)
SEQUENCE DESCRIPTION REGISTERS
1 Select DAC audio source 0x10
2 Select music filters 0x11
3 Set output volume 0x1C, 0x1D
4 Set line output volume 0x1E, 0x1F
5 Select headphone mode 0x24
6 Enable line outputs and DAC as required 0x26
7 Enable LRCLK and BCLK (if operating in slave mode) N/A
8 Enable MAX9880A 0x27
9 Enable external amplifier (if using) N/A
Table 28. Music Playback
Applications Information
Proper layout and grounding are essential for optimum
performance. When designing a PCB for the
MAX9880A, partition the circuitry so that the analog
sections of the MAX9880A are separated from the digi-
tal sections. This ensures that the analog audio traces
are not routed near digital traces.
Use a large continuous ground plane on a dedicated
layer of the PCB to minimize loop areas. Connect
AGND and DGND directly to the ground plane using
the shortest trace length possible. Proper grounding
improves audio performance, minimizes crosstalk
between channels, and prevents any digital noise from
coupling into the analog audio signals.
Ground the bypass capacitors on MICBIAS, REG,
PREG, and REF directly to the ground plane with mini-
mum trace length. Also be sure to minimize the path
length to AGND. Bypass AVDD directly to AGND.
Connect all digital I/O termination to the ground plane
with minimum path length to DGND. Bypass DVDD and
DVDDS1 directly to DGND.
Route microphone signals from the microphone to the
MAX9880A as a differential pair, ensuring that the posi-
tive and negative signals follow the same path as
closely as possible with equal trace length. When using
single-ended microphones or other single-ended audio
sources, ground the negative microphone input as
close to the audio source as possible and then treat the
positive and negative traces as differential pairs.
The MAX9880A TQFN package features an exposed
thermal pad on its underside. Connect the exposed
thermal pad to AGND.
An evaluation kit (EV kit) is available to provide an
example layout for the MAX9880A. The EV kit allows
quick setup of the MAX9880A and includes easy-to-use
software allowing all internal registers to be controlled.
Startup Sequences