In recent years, technological innovations in the automotive field—such as autonomous driving and ADAS—require a wider variety of sounds, including warning sounds for lane departures and surrounding obstacles. As a result, even instrument cluster audio output systems now use speaker amplifiers with a microcontroller (MCU) to generate sound, instead of relays for turn signal sounds and electronic buzzers for warning sounds. However, until now, ensuring safe and stable sound output at high volumes has been challenging.
ROHM has developed the BD783xxEFJ-M series for vehicle instrument clusters, which require multiple high-volume sound outputs, including warning sounds, turn signals, welcome tones, and voice guidance. Furthermore, the adoption of a new type of overcurrent protection circuit (OCP) provides protection against output short circuits (damage due to accidental terminal contact) to deliver a high output power of 2.8W, which was previously difficult to achieve. In addition to overcurrent protection, built-in thermal shutdown and ultra-low voltage lockout (UVLO) ensure highly reliable protection against abnormal conditions.
Moreover, compliance with the AEC-Q100 automotive reliability standard and the ability to withstand high-temperature operation up to 105°C allow for stable voice output without compromising functionality, even under demanding conditions.
ROHM is committed to contributing to greater safety and comfort by developing high-quality, reliable products for the automotive sector, where sound diversification is constantly increasing.
Key features
1. High output power of 2.8W with built-in overcurrent protection.
With conventional overcurrent protection circuits, the maximum output is limited, as the operating threshold of the protection circuit must be set to a value lower than the maximum current that the speaker amplifier can provide.
Conversely, ROHM's new overcurrent protection circuit eliminates the need to limit output power, preventing waveform distortion even at high power levels. This allows the BD783xxEFJ-M series to provide overcurrent protection against output short circuits, which was difficult to achieve in the past, in combination with high output power (2.8 W max. into 4Ω load and 10% distortion).
2. Ensure high reliability in vehicle applications
The BD783xxEFJ-M series is qualified to meet the AEC-Q100 automotive reliability standard and withstands a maximum operating temperature of 105°C. Simultaneously, the adoption of a high-power driver reduces heat generation even at high volumes, resulting in stable audio output without compromising functionality, even under demanding conditions. In addition to overcurrent protection, thermal shutdown and low-voltage lockout are incorporated, preventing damage caused by abnormal heat generation and unexpected popping noises during battery interruptions.
Installed on the Cypress Semiconductor reference board,
ROHM's BD783xxEFJ-M series speaker operational amplifiers are mounted on the evaluation board of Cypress Semiconductor's Traveo™ range of S6J3360 series frame MCUs for automotive applications, allowing for easy evaluation under real-world conditions.
product range
offers products with output gains of +6dB (BD78306EFJ-M), +10dB (BD78310EFJ-M), and +26dB (BD78626EFJ-M). The range will be expanded to include a total of 11 models ranging from +6dB to +26dB in 2dB steps.
Availability: immediate
Application examples:
Automotive instrument clusters,
vehicle emergency call systems,
ADAS-related applications requiring voice functionality
, and other applications requiring voice output for notification, warning, and guidance in vehicle environments.
