- Acoustic Vehicle Alerting System (AVAS)
- External vehicle alert sounds (e.g., opening/closing of sliding doors, charging completion)”
LAPIS Technology, a subsidiary of the ROHM Group, has launched the industry’s pioneering speech synthesis integrated circuits (ICs) — the ML22120xx series — specifically engineered for use in acoustic vehicle alerting systems (AVAS) in electric vehicles (EVs).
As the world moves towards a carbon-neutral society, the prevalence of silent-running hybrid and EVs is on the rise. This has led to the implementation of AVAS regulations, mandating these vehicles to produce a warning sound for pedestrian safety. However, creating such a warning sound using a microcontroller unit (MCU) necessitates smooth control of pitch and volume, and adjustments to match the vehicle’s geometry. This process increases the software development load on the MCU, requiring additional verification with other software processes within the MCU.
To alleviate this burden, LAPIS has launched new products that leverage their expertise and technology in speech synthesis ICs. The goal is to produce high-quality sound through a unique hardware-based setup. The ML22120TB and ML22120GP models incorporate hardware functions such as a warning sound generator, fader, and equalizer. This hardware configuration eliminates the need for software validation, significantly reducing development time compared to MCU-based designs.
Additionally, dedicated GUI software simplifies compliance with AVAS regulations regarding volume and frequency characteristics. The new IC system can be controlled using simple commands, enabling the warning sound to be initiated in less than a tenth of the time required by traditional MCU-generated systems. A built-in fault detection function identifies both communication errors with the main controller and oscillation errors caused by external components, thereby enhancing vehicle reliability. These ICs can be applied in various scenarios, including: