STMicroelectronics launches Class-D amplifier for high-definition automotive audio

The HFDA801A from STMicroelectronics is a high-resolution audio amplifier that’s specifically designed for compact, cost-effective automotive applications. The HFDA801A is a 2MHz switching pulse-width modulation (PWM) Class-D amplifier with a quad-bridge configuration.

An integrated high-performance digital-to-analog converter (DAC) ensures hi-fi quality sound under any load condition, with noiseless turn-on/turn-off and without creating any output artifacts. With a signal-to-noise ratio of 121dB, 120dB dynamic range, and only 10μV output noise, the HFDA801A delivers an extraordinary level of audio performance from an inexpensive small form-factor component.

The feedback configuration with an integrated L-C low-pass filter provides an ultra-wide flat frequency response up to 80kHz and minimizes dependence on external components. The wide bandwidth allows use in high-definition (HD) audio applications, letting designers rely on excellent linearity and low distortion that is independent of the inductor and capacitor quality.

The specific architecture implemented derives all required voltages internally, enabling the HFDA801A to draw its supply from the vehicle battery without the need for additional power converters. The amplifier benefits from a wide range of load capabilities, ensuring stable performance even while driving high power on low-impedance loads of 2Ω on all four channels.

In addition, by integrating in-play diagnostics and a digital impedance meter and real-time load-current monitor, the HFDA801A can be used in safety-related audio applications that must demonstrate ASIL compliance, such as Acoustic Vehicle Alerting Systems (AVAS).