LAPIS Semiconductor’s Speech Synthesis ICs Equipped with Playback Anomaly Detection Function

Contributes to dramatically improved speech synthesis quality in ADAS

Yokohama, Japan and Santa Clara, Calif., July 23, 2020 (GLOBE NEWSWIRE) -- ROHM Group company LAPIS Semiconductor recently announced the automotive speech synthesis ICs, ML2253x series, optimized for audible notifications and sound effects in ADAS (Advanced Driver Assistance System) and AVAS (Acoustic Vehicle Alerting System).

In recent years, the increasing proliferation of ADAS and other safety systems designed to notify drivers of vehicle operation and the surrounding environment is prompting auto manufacturers to develop audio systems that utilize sound effects and voice to issue warnings and alerts. As such, reliable voice generation is demanded of these audio systems, which play a major role in maintaining the safety of vehicle occupants and pedestrians. However, conventional solutions utilizing middleware for voice playback are often comprised of multiple components and place a heavy load on the main MCU, requiring significant man-hours to support countermeasures to avoid risk along with software that responds to system changes.

In contrast, LAPIS Semiconductor’s new product not only improves quality by detecting audio defects using a playback anomaly function, but also facilitates system configuration while simplifying software design for the main MCU. LAPIS Semiconductor speech synthesis ICs incorporate all required amps, communication I/F, logic ICs, and memory, enabling configuration of voice prompt systems independently of the main MCU. As a result, they are seeing increased adoption in automotive applications.

The ML2253x series also includes a playback sound anomaly function that can send error signals to the main MCU. This makes it possible to detect playback anomalies such as skipping, contributing to further improvement in the quality of automotive audio output systems. Compared with the conventional compression algorithm, HQ-ADPCM enables to achieve high fidelity sound without distortion. In addition, flash rewrite function from the main MCU enables rewriting of voice data even after shipment.

LAPIS Semiconductor is committed to continue to develop speech synthesis ICs that provide greater convenience by reducing sound design man-hours while supporting safety and comfort of society. 

Key Features 

1. Playback anomaly detection function contributes to improved quality in voice prompt systems

The ML2253x series incorporates a new playback anomaly detection function that re-digitizes the analog speaker output signal and compares it with the playback data stored in the IC in order to feedback an error signal to the main MCU when an anomaly above the set value is detected. This makes it possible to improve the quality of the entire system.