Datasheet
Maxim Integrated
│
131
MAX98090 Ultra-Low Power Stereo Audio Codec
www.maximintegrated.com
Figure 33. Receiver Output Functional Diagram
Analog Class AB Congurable
Receiver/Line Output
The device features a configurable analog Class AB pro-
grammable gain amplifier output that can be configured to
act either a mono differential output or as a stereo single-
ended output. When configured as a differential analog
output (LINEMOD = 0, Table 61), the driver is an ideal
receiver driver capable of driving both 16Ω and 32Ω differ-
ential loads (such as an earpiece speaker). In the receiver
configuration, the mono output of the left receiver/line
output mixer is routed to both the left and right output driv-
ers in a bridge tied load (BTL) configuration (Figure 33).
In this configuration, the mixer input signal source(s) and
both the mixer and output amplifier gain settings are deter-
mined by the left channel registers. All right output channel
register settings have no effect in receiver/earpiece mode.
When configured as a stereo single-ended analog out-
put (LINEMOD = 1, Table 61), the driver is optimized for
standard ground referenced, high impedance line outputs.
In the line output configuration, the output of the left and
right line output mixers are individually routed to the left
and right output drivers (respectively, Figure 34). In this
configuration, both channels are configured individually
by the left and right channel registers.
Receiver/Earpiece Mixer and Gain Control
When configured as a differential receiver output, only the
left output configuration registers are used. The receiver
mixer can be configured to accept any combination of
signals from the playback DAC, the analog microphone
amplifiers, and the line input drivers (Table 58). The
receiver input mixer also provides several attenuation
options (Table 59). The mixer attenuation options of -6dB,
-9.5dB, and -12dB are sized to prevent clipping when
several full-scale input sources are selected.
The receiver output is a programmable gain amplifier
(PGA) capable of driving a wide range of differential loads
(including standard 16Ω and 32Ω earpiece speakers). The
receiver PGA has a wide volume adjustment range from
-62dB to +8dB, provides a high attenuation mute control
(Table 60), and features programmable click and pop
reduction options. See the Click-and-Pop Reduction sec-
tion for details. The receiver PGA output common-mode
voltage is either half of V
AVDD
(in resistive divider BIAS
mode) or about 0.78V (in bandgap BIAS mode).
DACR
DACL
MIC 1
MIC 2
LINE A
LINE B
RCV/
LINE
OUT
RIGHT
MIXER
DACR
DACL
MIC 1
MIC 2
LINE A
LINE B
RCV/
LINE
OUT
LEFT
MIXER
LINMOD
RCV/
LINE
OUT
MUX
-12dB TO 0dB
RCVLVOL[4:0]
RCVLM
RCVLEN
RCVRVOL[4:0]
RCVRM
RCVREN
MIXRVCL[5:0]
MIXRVCLG[1:0]
MIXRVCL[5:0]
MIXRVCLG[1:0]
-62dB TO 8dB
-12dB TO 0dB
LINE OUT
RIGHT PGA
-62dB TO 8dB
RCVP/
LOUTL
RCVN/
LOUTR
LINE OUT
LEFT PGA
ANALOG
INPUT
DRIVERS
DACLEN DACRENDACHP
PERFMODE
DAC
LEFT
DAC
RIGHT
FLEXSOUND
TECHNOLOGY
DSP
SPEAKER/
HEADPHONES
MAX98090
ZDEN
VS2EN
ZSEN