The Industry’s First* Speech synthesis ICs dedicated for AVAS (Acoustic Vehicle Alerting System) in xEVs

The ROHM group company LAPIS Technology has developed the industry’s first speech synthesis ICs – the ML22120xx series (ML22120TB, ML22120GP) – designed for AVAS 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 that require a warning sound 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.

Application Examples
Acoustic Vehicle Alerting System (AVAS), external vehicle alert sounds (sliding door open/close, charging completion), etc.

Click on the link below for more information on the new speech synthesis ICs.

Evaluation Board, GUI Software Information
An evaluation board along with 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.

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 – Online Distributors: DigiKey, Mouser and Farnell
Sound Device Control Kit Part No: SDCK3 – Online Distributors: DigiKeyMouser and Farnell

Visit ROHM’s Website for More Information

*LAPIS Technology January 17, 2024 study


About ROHM Semiconductor
ROHM Semiconductor is a global company of 507.8 billion yen (3.9 billion US dollars) per March 31st, 2023, with over 23,700 employees. The company develops and manufactures a very large product range from SiC Diodes and MOSFETs, Analog ICs such as Gate Drivers and Power Management ICs to Power Transistors and Diodes to Passive Components. The production of ROHM’s high performing products is taking place in state-of-the-art manufacturing plants in Japan, Germany, Korea, Malaysia, Thailand, the Philippines, and China. ROHM Semiconductor Europe has its Head Office near Dusseldorf serving the EMEA region (Europe, Middle East, and Africa).
For further information, please contact