AudioSmart® CX20921 Dual-Mic Far-Field Voice Processor SoC

Standalone 2-Mic Far-Field Subsystem with Integrated Low-Power Wake-on-Voice (WoV)

The Synaptics CX20921 is a high-performance, far-field voice input processor System-on-Chip (SoC). The CX20921 is the first product in this category with an integrated voice trigger function that supports a low system power Wake-on-Voice (WoV) function. The device includes two 24-bit microphone Analog-to-Digital Converters (ADCs), a powerful dual core 32- bit hardware Digital Signal Processor (DSP), and integrated power management.

Combined with Synaptics AudioSmart® far-field voice input processing software suite, including Smart Source Pickup (SSP) noise suppression and full-duplex stereo Acoustic Echo Cancellation (AEC), the CX20921 is the ideal turnkey solution for adding voice control, voice search, and Voice over Internet Protocol (VoIP)/speakerphone functionalities to SmartTV, SetTop Box (STB), Smart appliances, digital assistants, and automotive hands-free control and communication systems.

The CX20921 device supports a microphone array with up to two synchronized ADCs and programmable preamplifiers. Each pre-amplifier is paired with a dedicated bias supply to eliminate crosstalk. The entire input path guarantees 106dB dynamic range, which maximizes speech-to-noise ratio with low boost and prevents microphone saturation.

System Block Diagram

Synaptics’ proprietary far-field AudioSmart software leverages the built-in hardware to deliver a superior voice interactive experience in the most challenging room environments. The voice processing chain also supports multiple modes of processing, which are independently optimized for voice communication and automatic speech recognition.

When ADC and DSP are active in the Wake-on-Voice (WoV) mode, the device consumes less than 70mW, which is well below the 0.5W EC 1275/2008 requirement for standby power.

Applications

• Voice-controlled Smart TV/STB
• Smart Bluetooth/WiFi speaker
• Voice interactive smart appliances
• Internet of Things (IoT) devices
• Automotive hands-free control/communication