The first speech synthesis ICs tailored for AVAS in xEVs (electric vehicles) developed by LAPIS Technology – a ROHM group company.
The new ML22120xx series (ML22120TB, ML22120GP) speech synthesis ICs are touted to mitigate the burden of AVAS development.
While AVAS emits a warning sound to alert pedestrians of their approach, it does it with the help of an MCU.
The new LAPIS speech synthesis ICs achieve high-fidelity sound using a novel hardware-based configuration.
The unique integrated hardware function of ML22120TB and the ML22120GP 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 communications with the main controller and erroneous oscillation caused by external components – contributing to vehicle reliability.
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 warning sound to be emitted to alert pedestrians of their approach.
Application Examples
- Acoustic Vehicle Alerting System (AVAS)
- external vehicle alert sounds (sliding door open/close, charging completion), etc.
Acoustic Vehicle Alerting System (AVAS), external vehicle alert sounds (sliding door open/close, charging completion), etc.
For more information on the new speech synthesis ICs: https://www.rohm.com/lapis-tech/product/speech/ml22120
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.
Online Sales Information
Online Distributors: DigiKey, Mouser and Farnell
Pricing: $7.0/unit (samples, excluding tax)
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: DigiKey, Mouser and Farnell
AVAS Regulation
The mandatory implementation of Acoustic Vehicle Alerting System (AVAS) was adopted by the United Nations Economic Commission for Europe’s (UN/ECE) World Forum for Harmonization of Vehicle Regulations (WP29) under UN Regulation No. 138 on Quiet Road Transport Vehicles. This regulation stipulates the volume of warning sound for approaching vehicles and frequencies at certain vehicle speeds.
