Class-D Automotive Audio Amplifier with Hi-Fi Audio Quality and Advanced Diagnostics for Compact Audio and Alerting Systems

Published  March 3, 2021   0
HFDA801A Class-D Automotive Audio Amplifier from STMicroelectronics

The HFDA801A from STMicroelectronics is a 2MHz switching pulse-width modulation (PWM) Class-D amplifier designed for compact, cost-effective automotive applications. This new ASIL-ready high-resolution audio amplifier from the company comes 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 amplifier 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 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. Various load capabilities of the amplifier contribute to stable performance even while driving high power on low-impedance loads of 2Ω on all four channels.

By integrating in-play diagnostics as well as 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). The device is currently sampling and the production is scheduled for the second half of 2021.