CONEXANT CX20704

Audio
Speakers-on-a-Chip
Speakers-on-a-Chip with On-chip Voice/Audio DSP, Integrated
I2S/I2C Codec, and Mono Class-D Amplifier
CX20704
Conexant’s portfolio includes a comprehensive suite of semiconductor
solutions for communications and consumer applications.
The CX20704 is one of Conexant’s Speakers-on-a-Chip (SPoC) embedded
audio solutions for convergence audio entertainment and voice communication
applications. The SPoC features a proprietary on-chip Digital Signal Processor
(DSP), Codec, Mono Class-D Amplifier, I2S and I2C interfaces, high
performance 24-bit DAC’s and ADC’s, a range of digital and analog input/
output channel selections for flexible routing and mixing, and a stereo capless
headphone driver in a cost-effective single-chip package. The solution features
a suite of turnkey audio and voice enhancement algorithms designed for
applications such as Portable Navigation Devices, Portable Media Players,
Multimedia IP phones, and Mobile Internet Devices. This product is part of the
CX2070x SPoC family, which includes CX20702, CX20703, CX20705, CX20706,
CX20707 and CX20709.
The device features multiple high performance 24-bit DACs for stereo speaker
output, multiple 24-bit high performance ADCs supporting mono microphone
and one stereo line input, capless headphone output, support for bi-directional
12S, PCM, S/PDIF-out with independent sampling rates, and a range of digital
and analog input/output channel selections for flexible routing and mixing.
Different audio sampling rates ranging from 8 kHz to 96 kHz are generated
directly from the master clock without the need for external PLL. The powerefficient mono Class-D amplifier drives a maximum of 2.5 Watt (average) from
the integrated amplifier. The device can be controlled and configured by both
read and write capability through I2C and Serial Peripheral Interface (SPI).
The on-chip Digital Signal Processor (DSP) runs a suite of innovative Conexant
proprietary voice processing algorithms and audio post processing effects that
dramatically improves sound quality and frees-up processing power for other
applications without compromising on cost and future firmware scalability. Key
audio innovations include Subband Acoustic Echo Suppression and Cancellation,
Noise Reduction, Dynamic Loudness Adapter, Mic Auto Gain Control, Digital
Equalizer, Dynamic Range Compression, and 3D effects. The embedded SPoC
Configuration Toolbox allows for fast configuration and performance optimization.
The CX20704 turnkey solution eliminates the need for a multiple-chip reference
design, making it easy and economical for manufacturers to design products
for high quality audio and voice applications. A complete evaluation kit with
reference board and all the necessary technical documents and software is
available.
The SoC is packaged in an environmentally-friendly, RoHS/Green-compliant 76-pin
QFN (Quad Flat No leads) package.
Distinguishing Features
• 24-bit DAC/ADC, SNR 102 dB, THD - 92 dB at
48 kHz 3.3 V
• Programmable on-chip proprietary DSP
– Subband acoustic echo suppression and cancellation
– Noise reduction
– Dynamic loudness adaptor
– Mic auto gain control
– Digital equalizer (10 bands/channel)
– Dynamic range compression
– 3D Expander (Phantom mode and Immersion mode)
• 5-wire digital audio I/O (I2S/PCM/SPDIF-out), supporting full duplex independent sampling rates
• One 2-wire I2C or 4-wire SPI slave interface for external MCU
• 2.5 W BTL mono Class-D speaker amplifier
• One microphone interface with on-chip bias supply
• Flexible power management
• Audio sample rate: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 64, 88.2, 96 kHz
Applications
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•
•
•
Portable Navigation Device
Part Number CX20704
Portable Media Player
Description
Multimedia IP phone
Mobile Internet Device
Speakers-on-a-Chip with On-chip
Voice/Audio DSP, Integrated I2S/ I2C Codec, and Mono Class-D Amplifier
Audio
Speakers-on-a-Chip
CX20704 Features
CODEC
• 5-wire digital audio I/O (I2S/PCM/SPDIF), supporting full duplex independent sampling rates
• One 2-wire I2C or 4-wire SPI slave interface for external MCU
• Eight GPIO pins
• 2.5 W mono Class-D speaker amplifier
• Single-ended or differential stereo analog audio input
• One microphone interface with on-chip bias supply
• Integrated 50 mW headphone driver with jack sense
• Single-ended or differential line out
• 24-bit DAC/four ADC, SNR 102 dB, THD - 92 dB at 48 kHz 3.3 V
• Audio sample rate: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 64, 88.2, 96 kHz
• 90 dB dynamic range with 0.01percent THD+N at 4 Ω load
• Spread Spectrum for filter-less, low EMI output
• 10-bit ADC multiplexed to support analog volume potentiometer and DC level detection
SE or Diff Line In
• Flexible power management
• Variable master clock rates
DSP
• Subband acoustic echo suppression and cancellation
• Noise reduction
• Dynamic loudness adaptor
• Mic auto gain control
• Digital parametric equalizer (10 bands/channel)
• Dynamic range compression
• 3D Expander (Phantom mode and Immersion mode)
SPoC Configuration Toolbox
• Fast configuration tool via USB-to-I2C from PC
• Device configuration and DSP parameter adjustment
• Output log for convenient MCU programming
M
SE or Diff Line In
3
M
SE or Diff Line In
DSP
ADC
M
SE or Diff Line In
M
3
ADC
Memory
DMA
DAC
Capless HP
Out 32 W
DAC
Capless HP
Out 32 W
DMA
Matrix 1
Matrix 0
GPIO 3
GPIO 4
GPIO 2
Matrix 2
MON
ADC
Volume
Voltage
Monitor
EEPROM DATA
EEPROM CLK
TX
RX
UART
CSN
MSO
SSCL
TX_DAT
SDA/MOSI
SPI
I2C Slave
PCM/I2S
Jack
Sense
CLK
Sense
SE or Diff
10K Line
Controller
DMA
Clock
Circuitry
TX_WS/SPDIF
XTAL Out
SE or Diff
10K Line
Bias
Generator
RX_DAT
XTAL In/
Master In
GPIO 1
GPIO 0
ADC
RX_WS
MIC Bias
2.5 W Class-D
DSP
MIC In
CX20704 Interface Diagram
The CX20704 is offered in a 76-pin QFN package
Conexant Product Portfolio
Conexant’s comprehensive product portfolio includes solutions for imaging, audio, embedded modem and video surveillance applications.
© 2009 Conexant Systems, Inc. All Rights Reserved. Conexant and the Conexant
logo are registered trademarks of Conexant Systems, Inc. All other trademarks
are owned by their respective owners. Although Conexant strives for accuracy
in all its publications, this material may contain errors or omissions and is
subject to change without notice.
This material is provided AS IS and without
any express or implied warranties, including merchantability, fitness for a
particular purpose and non-infringement.
Conexant shall not be liable for any
special, indirect, incidental or consequential damages as a result of its use.
09-2910
www.conexant.com
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Doc# PBR-202453