Conexant Confidential • www.conexant.com • 020PBR00
Turnkey Solution Enabling Far Field Voice Control
and Telepresence Applications
Product Overview
The CX20865 is the industry-leading far field voice input
processor SoC, designed for voice interactive
applications. The CX20865 includes high-performance
microphone ADCs, a powerful dual-core 32-bit
hardware DSP, and integrated power management.
Combined with Conexant’s advanced far field voice
processing algorithms, the CX20865 is the ideal turnkey
solution for adding voice control, voice search, and
telepresence functionalities to SmartTV, STBs, and
game console appliances.
The CX20865 supports a microphone array with up to four
synchronized ADCs and programmable pre-amplifiers.
Each pre-amplifier is paired with a dedicated bias supply
to eliminate crosstalk. The entire input path guarantees a
106dB dynamic range, which maximizes speech-to-noise
ratio with low boost and prevents microphone saturation.
Conexant's proprietary far field voice processing
algorithms take advantage of the high-performance
processing core and ADCs to deliver superior voice
interactive experiences in the most challenging room
environments. The full-featured Smart Source Pickup
(SSP) algorithm significantly improves the voice control
accuracy in noisy situations, such as retail showrooms,
living and family rooms, and other gathering places. The
voice processing chain also supports multi-thread
processing streams, independently optimized for voice
communication and automatic speech recognition.
The CX20865 device has an integrated DC-DC
converter that supports frequency scaling mechanisms
to reduce power consumption. When the ADC and DSP
are active in Voice-on-Wake mode, the device
consumes less than 70mW, well below the 0.5W EC
1275/2008 requirement for standby power.
Applications
•Voice interactive SmartTV/STB
•Voice-controlled appliance
•Telepresence
•Far field audio capturing
•Game console
•Automotive
Key Features
•Speech recognition optimization for leading ASR
engines
•SkypeTV certified with Watch Live and Talk®
•
SSP noise reduction technology
•Stereo AEC that supports a 2.1 or 2.2 CH system
•Low power, WoV mode with buffering and keyword
detection
•Programmable 32-bit digital audio processor
•Four microphone ADCs with 106dB full path
dynamic range
•Raw audio sample rates of 8kHz~96kHz
•0.125dB analog front-end gain resolution
•Independent microphone bias for low crosstalk
•Serial data interface (I2S/PCM)
•Asynchronous SRC and sync buffers
•USB full-speed, 2.0 UAC compliant, asynchronous
data transfer
•I2C and UART host interfaces
•Serial EEPROM interface
•Integrated DC-DC for power management
• 9x9mm 169-BGA package, RoHS compliant
System Block Diagram
CX20865 Far Field Voice Processor
AudioSmart™ Product Brief