Optimised for smart speakers and smart home applications, a development kit from Cirrus Logic allows manufacturers to bring to market Amazon's Alexa voice service-enabled products that feature accurate wake-word triggering and command interpretation even in noisy environments and during music playback.

The low power Voice Capture development kit for Alexa includes a reference board that features Cirrus Logic’s CS47L24 smart codec, CS7250B digital MEMS microphones and SoundClear algorithms for voice control, noise suppression and echo cancelation.

Cirrus_Logic_AVS-Dev-Kit (cr) Figure 1: Voice Capture development kit for Alexa (Source: Cirrus Logic)

Cirrus Logic’s voice capture reference design suppresses noise and other real world interference for more accurate and reliable voice interactions. The technology improves Alexa wake-word detection in both quiet and noisy environments and with the user several meters away from the device. Cirrus Logic’s echo cancellation technology allows the user to “barge” into or interrupt loud music playback and Alexa responses, so Alexa can respond accurately to new requests, according to the company.

The ultra-low noise floor and wide dynamic range (130dB) of Cirrus Logic’s MEMS microphones assure precise voice capture in challenging noise conditions, enabling Cirrus Logic’s SoundClear algorithms to block noise that would otherwise interfere with Alexa wake-word and request accuracy.

Cirrus Logic’s smart codec integrates hi-fi DACs, a stereo headphone amp and mono speaker amp to provide OEMs with a low cost bill of materials for products ranging from high-end speakers to simple digital assistants. Designed with the needs of low power portable devices and accessories in mind, it typically consumes 80% less power versus competing solutions.

The kit is a complete solution that includes a voice capture board with high performance two-microphone array, Raspberry Pi 3 (RPi3), speaker and a microSD card preloaded with all required firmware for instant productivity. Cirrus Logic’s control console simplifies operation of the various RPi3 applications and provides a user-friendly interface to perform acoustic tuning and diagnostic functions. The voice capture reference board’s schematic design and bill of material are designed for use in most AVS applications with minimal customization, further reducing time-to-market.

The Cirrus Logic CRD1569-1 Voice Capture Development Kit for Amazon AVS is available to qualified commercial device manufacturers through Digi-Key.