Audio
Embedded Audio
CX20745 Features
CODEC
• Stereo 8/16/24-bit DAC supports sample rates
capable of 8, 8.018,11.025, 12, 16, 16.0364,
22.05, 24, 32, 44.1, 48, 88.2, and 96 kHz,
depending on the master clock
– 98 dB Dynamic Range
– -85 dB THD
• Stereo 8/16/24-bit ADC supports sample rates
capable of 8, 8.018,11.025, 12, 16, 16.0364,
22.05, 24, 32, 44.1, 48, 88.2, and 96 kHz,
depending on the master clock
• Supports master clock of 24.576 MHz and
22.5792 MHz
• Data interface: I2S that can be converted to
PCM, I2S/PCM are slave only
• Control Interface: I2C slave only
• Audio ports:
– Stereo analog input port supporting up to
one single-ended stereo microphone,
one differential mono microphone, one
single-ended stereo line-In, or one
differential mono line-in
•
•
•
•
•
– 4-conductor OMTP headset set jack
compliant with integrated in-line command
sensing. Mic bias sensing capability for
external headset control. Supports sense
and switching between MIC and GND pins
– Stereo class-D amplifier
– Stereo capless headphone port
– Single-ended analog line output (stereo)
– Digital microphone input (stereo)
Class-D amplifier with the following modes of
operation:
– Up to 2 W per channel into 4Ω with 5 V
supply
– Up to 1 W per channel into 4Ω with 3.3 V
supply
– Spread Spectrum for EMI protection on the
class-D amplifier
Line-In loopback mode, where the input signal
will loop back to the DAC for playback with EQ
PopShield active anti-pop circuit
Device can operate in 3.3 V only mode
Integrated LDO converting 5 V to 3.3 V, and
3.3 V to 1.8 V
• PDM digital MIC interface supporting clock
frequency of 3.072 MHz and 1.536 MHz
• Supports industrial temperatures of -40~85C
• Jack sense supporting up to four jacks
• Codec provides independent gain and mute
control for both DAC and ADC
• Four General purpose GPIOs
– GPIO1 and GPIO2 can be configured for
“Infinity Volume Control” using a rotary
encoder
DSP
• Digital parametric equalizer (5 bands/
channel)
• Dynamic range control including
compressor and limiter
• Microphone automatic gain control
Power Management
• Idle Mode: 2.2 mA with 10 ms fast
resume
• Sleep Mode: 0.5 mA (digital supply only)
with 200 ms resume
SENSE_A
Jack
Sense
Bias
Generator
50mW Capless HP Out
32
Ω
50mW Capless HP Out
32
Ω
2W Class-D
4
Ω
MIC BIAS
Line/Mic In
M
ADC
AGC
M
Σ
+
-
Line/Mic In
M
Five
Band
EQ
DRC
PWM Out
DAC
Fault
2W Class-D
4
Ω
DAC
PWM Out
ADC
AGC
M
Σ
Five
Band
EQ
DRC
M
10K Line
M
MIC Data
MIC Clock
Digital
Mic
10K Line
Master
Clock
Clock
Circuitry
I
2
C Slave
PCM/I
2
S
PCM/I
2
S
1.8 V
LDO
3.3V
LDO
SCL
SDA
3.3V_IN
1.8V_FILT
5.0V_IN
RX_WS/SYNC
CX20745 System Block Diagram
The CX20745 is offered in a 48-pin QFN package
Conexant Product Portfolio
Conexant’s comprehensive product portfolio includes solutions for imaging, audio, video surveillance, and embedded modem applications.
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in all its publications, this material may contain errors or omissions and is
subject to change without notice.
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ANy eXPreSS or IMPlIeD wArrANTIeS, INCluDINg MerCHANTABIlITy, FITNeSS For A
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Doc# PBR-202653
special, indirect, incidental or consequential damages as a result of its use.
10-2947
TX_WS/SYNC
3.3V_FILT
BIT_CLK
RX_DAT
BIT_CLK
TX_DAT
CONEXANT [ CONEXANT SYSTEMS, INC ]
