ROHM Group Company LAPIS Technology Introduces the Industry’s First Speech Synthesis ICs Dedicated to AVAS in Electric Vehicles

ROHM Group company LAPIS Technology today introduced the industry’s first[1] speech synthesis ICs – ML22120xx series (ML22120TB, ML22120GP) – designed for AVAS (Acoustic Vehicle Alerting System) in xEVs (electric vehicles).

In order to achieve a carbon neutral (decarbonized) society, the number of hybrid and electric vehicles that silently operate on motor power continues to increase, prompting AVAS regulations to be enacted requiring a warning sound to be emitted to alert pedestrians of their approach. However, when generating a warning sound using an MCU, the pitch and volume must be smoothly controlled, and characteristics adjusted to match the vehicle geometry. This increases MCU software development load, requiring verification with other software processes inside the MCU. In response, LAPIS Technology released new products that contribute to reducing the burden of AVAS development by leveraging experience and technology with speech synthesis ICs. The aim: achieving a high-fidelity sound using a novel hardware-based configuration.

The ML22120TB and the ML22120GP integrate hardware functions that include a warning sound generator, fader, and equalizer. Unlike MCU-based designs, the hardware configuration eliminates the need for software validation, significantly reducing development time. At the same time, dedicated GUI software makes it easy to comply with regulations for volume and frequency characteristics required for AVAS.

The system of new ICs can be controlled by simple commands, allowing warning sound to be started in less than one-tenth the time of conventional MCU-generated systems. An included fault detection function detects both erroneous communication with the main controller and erroneous oscillation caused by external components, contributing to vehicle reliability. 

Product Lineup
View the product lineup here: ML22120xx

Application Examples

• Acoustic Vehicle Alerting System (AVAS)
• External vehicle alert sounds (sliding door open/close, charging completion)

Evaluation Board, GUI Software Information
An evaluation board and a Sound Device Control Kit [SDCK3] that includes dedicated GUI software are available, enabling easy evaluation of everything from sound generation to correction and trial listening of alert sounds.

Online Sales Information

• Online Distributors: DigiKey, Mouser and Farnell
• Availability: Now (OEM quantities)
• The products and evaluation board will be offered at other online distributors as they become available.

Product Information

• Applicable Part No: ML22120TBZ0B-MX
• Evaluation Board Part No: RB-D22120TB32
• Sound Device Control Kit Part No: SDCK3

Support
Click on the link below for more information on the new speech synthesis ICs:
https://www.rohm.com/lapis-tech/product/speech/ml22120

[1] LAPIS Technology study, January 2024