Automotive-Optimized Class-D Audio Amplifier with Advanced Diagnostics

With its innovative feedback-before-filter topology and a 2-MHz nominal PWM frequency, the HFA80A audio amplifier offers designers a unique opportunity to optimize output filters for specific performance targets. This approach allows for the achievement of a compact design with small component values, enhancing overall efficiency.

The amplifier's spread-spectrum operation plays a crucial role in simplifying compliance with the mandatory CISPR 25 specification. By eliminating the need for additional EMC-specific filtering, designers can focus on refining the audio performance without compromising on electromagnetic compatibility.

Delivering exceptional audio quality, the HFA80A is capable of driving up to 4x 49-W into 2Ω speakers at 14.4-V. With a typical harmonic distortion (THD) of just 0.015% (1-W/4Ω), the amplifier ensures a pure and powerful listening experience. Additionally, low output noise and crosstalk, along with an 80 dB power supply rejection at 1-W/1-kHz with 4Ω loads, further enhance audio clarity.

Designers can benefit from the amplifier's flat frequency response up to 40 kHz, providing ample bandwidth for high-resolution audio applications. By optimizing the filter, the bandwidth can be extended to 80 kHz, catering to the demands of modern audio systems. Moreover, the HFA80A's design enables seamless integration into noise-canceling applications, thanks to its low latency performance.

Equipped with automotive-specific diagnostics, the HFA80A features a robust noise-immune algorithm designed to detect anomalous load conditions and variations effectively. Key diagnostic capabilities include independent DC and AC load detection for each channel, short-circuit detection on startup, and configurable overcurrent protection thresholds. The amplifier also offers comprehensive checks for input-voltage DC-offset, output-current offset, and thermal protection, with a choice of four different thermal warnings.

To streamline communication with the host microcontroller, the HFA80A includes a dedicated, configurable pin that signals the availability of new diagnostic information. This feature not only simplifies host interactions but also reduces the CPU workload, enhancing overall system efficiency. Additionally, the amplifier's I2C-bus interface provides access to device features and diagnostic data, ensuring seamless integration into diverse applications.

Available in a compact 7- x 7-0mm LQFP48L thermally enhanced package with exposed pads, the HFA80A audio amplifier is priced competitively at $4.80 for orders of 1000 pieces. Its innovative features, combined with a focus on performance and reliability, make it a compelling choice for designers seeking a compact and powerful audio amplification solution.