Second-generation digital audio amplifiers offer improved performance compared to products released in 2012.
Simplifying system design and reducing costs for car radio suppliers.

STMicroelectronics has launched its second-generation power amplifiers that simplify car radio system design and enable drivers and passengers to enjoy high-quality sound even in compact cars.

According to ST, the FDA801 and FDA801B, the second-generation products of its four-channel Class-D[2] amplifiers, use digital input to directly convert digital audio sources into high-quality, spacious sound. This digital input method is immune to GSM noise, improves sound quality, reduces component costs, and simplifies system design. ST launched the world's first digital-input Class-D automotive audio amplifier in 2012 and has now accelerated its efforts with the second-generation products with improved features. These products will also be pin compatible to allow for a variety of multi-channel configurations in the near future.

“Class-D amplifiers are revolutionizing car audio across the market, from audiophile systems in luxury vehicles to affordable, high-quality sound in compact cars,” said Alfio Russo, Group Vice President and General Manager, Automotive Products Group, STMicroelectronics. “ST is committed to continuous development, and we believe these new products will set even more advanced performance and efficiency benchmarks for the industry.”


Through a digital impedance meter (Digital Impedance Meter, FDA801B)
Equipped with real-time speaker impedance measurement function

ST's new power amplifier delivers superior sound quality and improved energy efficiency. It also features a unique real-time speaker impedance measurement capability via the new Digital Impedance Meter (FDA801B), marking an unprecedented leap forward in automotive diagnostics.

This advancement was made possible by ST's advanced BCD9s process technology. This process minimizes interference between chip circuits, reduces standby power consumption, and prevents power transistor losses, boosting efficiency by over 93%.

FDA801/B helps improve vehicle fuel efficiency and extend the driving range of hybrid and battery-electric vehicles due to its low power loss. ST's new amplifier is compatible with fuel-saving start-stop technology and allows uninterrupted audio playback even when the vehicle's battery voltage drops to restart the engine.

The digital input and external feedback topology not only simplify circuit design but also improve frequency response regardless of load impedance and output filter design. This allows for the expansion of multiple variants based on a common platform without the need for detailed amplifier redesign. Unlike analog-input Class-D amplifiers, the FDA801/B's excellent noise immunity, low switching interference, and low power consumption, which allows for smaller heatsinks, make it suitable for use in head units as well as booster amplifiers.