Audio
Embedded Audio
CX20745 I2S Audio Codec SoC with Capless Headphone,
Digital Microphone and Integrated Stereo Class-D Amplifier
Low-power, cost-effective single-chip solution enables superior audio
The CX20745 is one of Conexant’s embedded
audio solutions specifically designed for
compact consumer electronics such as mobile
Internet devices, smartbooks, and Web tablets.
The low-power, energy-efficient device
features a proprietary inline configurable Digital
Signal Processing (DSP), Codec, stereo filter-
less Class-D amplifier with Spread Spectrum
Electromagnetic Interference (EMI) dispersion
technology, capless headphone driver, and
I2S interface in a cost-effective single-chip
package. The DSP runs a suite of turnkey
audio post-processing effects for enhanced
sound quality.
The chip features high performance multi-
bit DACs for speaker output, multi-bit high
performance ADCs supporting mono or array
microphones or one stereo line input, capless
headphone output, and a range of digital
and analog input/output channel selections
for flexible routing and mixing. The CX20745
contains a pair of
ProCoustic™
headphone
drivers supporting a full-range frequency
response at 98 dB dynamic range, and
headset jack support, which lowers Bill of
Materials (BOM) cost by eliminating the need
for external jack sense, external amplifier, and
Direct Current (DC)-blocking capacitors. The
codec supports four conductor-type Open
Mobile Terminal Platform (OMTP) headset
jacks with bias sensing for external headset
control. All output ports feature Conexant’s
PopShield DC cancellation to eliminate audio
pops and clicks that often occur during power
state transitions.
The CX20745’s power-efficient and flexible
Class-D amplifier drives up to 2 W into a 4Ω
speaker with 5 V supply or 1 W with 3.3 V
supply. The SPoC operates at 2.2 mA in stand-
by mode and 0.5 mA in sleep mode, which
enhances battery-operated devices through low
power consumption and low heat generation.
The device supports industrial temperatures
of -40~85C.
Audio
Speakers-on-a-Chip
The DSP runs a suite of 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. The fully
configurable hardware Equalizer, Dynamic
Range Control, and Microphone Automatic
Gain Control improves performance, maximizes
output volume, protects the speakers, and
enables far-field audio pick-up by broadening
the sound-capture radius for enhanced audio
quality. The CX20745 also features Hardware
Digital Volume Control, a feature similar to an
infinite volume control knob commonly found
in high-end audio-visual equipment.
The CX20745 turnkey solution eliminates the
need for a multiple-chip reference design and
includes Conexant’s software driver and design
support making it easy and economical for
manufacturers to design products for high
quality audio applications.
The SoC is packaged in an environmentally-
friendly, RoHS/Green-compliant 48-pin QFN
(Quad Flat No-leads) package.
Applications
• Consumer Electronics Embedded
Audio
• Mobile Internet Device
• Web Tablet Device
• Smartbook
Key Features
Class-D amplifier with Spread Spectrum
Benefits
FIlterless, low EMI, and power-efficient
speaker amplifier with ample power to drive up
to 2W/ch
Audio enhancement and optimization for
speakers and microphones
High performance audio fidelity with low
external interference
Pop and Click suppression and cancellation
<2.2.mA stand-by (Idle) mode or <.5mA sleep
mode
On-chip Digital Signal Processing
Multi-bit DACs/ADCs with fully differential
internal signaling
PopShield with DC offset cancellation
Low power stand-by and sleep
Part Number
CX20745
Description
I2S Audio Codec SoC with
Capless Headphone, Digital
Microphone and Integrated
Stereo Class-D Amplifier
CONEXANT [ CONEXANT SYSTEMS, INC ]
