Datasheet

Maxim Integrated │ 119
MAX98090 Ultra-Low Power Stereo Audio Codec
www.maximintegrated.com
Figure 23. Playback Path Block Diagram
Audio Playback Path
The device playback path has two channels (left and
right) and can accept digital audio input from the DAI
and/or the record path sidetone. The digital audio is then
routed through several stages of FlexSound DSP followed
by the digital to analog converter (Figure 23).
Playback Path FlexSound DSP
The first playback path section features the Maxim
FlexSound DSP stages. The first stage accepts and mixes
the DAI input with the record path sidetone (if enabled),
and contains separate digital gain and digital level control
stages. This stage is followed by three stereo DSP stages
including a 7-band parametric equalizer, a dynamic range
control section (DRC), and a digital filter stage. The play-
back path digital output is then routed into the DAC where
it is converted back to analog before being routed to the
analog output mixers.
Playback Path Digital Gain and Level Control
The stereo playback path DSP includes separate digital
gain and level control stages (Figure 24). Unlike the
record path, both playback path channels (left and right)
share the same digital gain and level control settings. The
coarse digital gain stage accepts its input from the DAI
digital data output and can be set from 0dB to +18dB in
6dB increments. The fine adjust, level control stage input
is the summation of the coarse gain stage output with the
record path sidetone signal. It can be adjusted from -15dB
to 0dB in 1dB increments (Table 49). The playback path
gain and level control stage also include a mute enable.
DVG[1:0]
FLEXSOUND
TECHNOLOGY DSP
DAI
SIDETONE FROM
RECORD PATH
RIGHT PLAYBACK PATH
TO THE
ANALOG
OUTPUT
MIXERS
LEFT PLAYBACK PATH
LEFT
SIDETONE
DSTS[1:0]
RIGHT
SIDETONE
LEFT 7-BAND
PARAMETRIC
EQUALIZER
RIGHT 7-BAND
PARAMETRIC
EQUALIZER
LEFT ALC:
AUTOMATIC
LEVEL CONTROL
B0_EQ_[23:0]
B1_EQ_[23:0]
B2_EQ_[23:0]
A1_EQ_[23:0]
A2_EQ_[23:0]
EQ_BANDEN
DVEQ[3:0]
EQCLP
LEFT
FILTERS
MODE
DHPF
RIGHT ALC:
AUTOMATIC
LEVEL CONTROL
RIGHT
FILTERS
DAC
LEFT
DAC
RIGHT
DAREN
DALEN
DVST[3:0]
DACHP
PERFMODE
DVM
DV[3:0]
LEFT
LEVEL
RIGHT
LEVEL
LEFT
GAIN
L/R ST
LEVEL
RIGHT
GAIN
DRCEN
DRCG[4:0]
DRCRLS[2:0]
DRCATK[2:0]
DRCCMP[2:0]
DRCTHC[4:0]
DRCEXP[2:0]
DRCTHE[4:0]