With the rapid development of electric cars and smart cars, consumers are increasingly aware of car sounds. The fewer speakers in traditional oil-burning cars are far from meeting customer needs. At present, cars equipped with more speakers have gradually become the mainstream of Chinese cars. Cars are equipped with more speakers and require more power amplifier chips, but the space of the car and power amplifier is expected to be more compact and integrated. The high efficiency, low heat generation and digitalization of Class D power amplifier chips are the future trend.

The automotive grade Class D audio amplifier HFDA801A introduced today is a 2MHz switching frequency, pulse width modulation (PWM) Class D amplifier using a four-bridge configuration and four channels. It integrates a high-performance Q digital-to-analog converter (DAC) and can provide high-fidelity sound quality under any load conditions. The turn-on/turn-off operation is noise-free and the output is lossless. The previous generation automotive-grade Class D audio amplifier FDA801 chip has been one of the most widely used automotive-grade chips on the market for many years since its introduction, and has been widely praised by the industry and market. However, this chip only supports 432K switching frequency. The new generation HFDA801A greatly increases the switching frequency, which can not only achieve compact and economical application design, but also achieve excellent audio performance levels.

HFDA801A is a new class D audio amplifier launched by STMicroelectronics. It is specially designed for automotive applications and uses the latest BCD technology. The HFDA801A integrates a 24-bit, 120 dB DAC converter and features a 2 MHz switching PWM Class D output stage. This configuration makes it possible to design compact and cost-effective applications while achieving excellent audio performance levels. The HFDA801A supports wideband applications (80 kHz) with extremely low noise levels and low total harmonic distortion (THD). In addition, it has the most comprehensive diagnostic matrix, including complete real-time diagnostics, to meet the most demanding OEM requirements in terms of loudspeaker control and system robustness/reliability. The HFDA801A supports start-stop functionality down to 4.5 V (5 V when on) and comes in a very compact and thin LQFP 10x10 package. Therefore, HFDA801A is suitable for any level of automotive applications.

Main features:

• AEC-Q100 qualification on going

• Integrated 120 dB D/A conversion

• I²S and TDM digital input (up to 16 CH TDM)

• Selectable input sample rate frequency (44.1/48/96/192 kHz)

• Wide supply operating range: 4.5 V - 2518 V (5 V min at turn-on transition)

• PWM 2 MHz switching PWM:

Reduced size and cost of output LC

• High Resolution Bandwidth support:

Up to 40 kHz (I²S 96 kHz) with attenuation [0 dB, -2 dB]

Up to 80 kHz (I²S 192 kHz) with attenuation [0 dB, -2 dB]

• 4 I²C addresses

• 4 Ω, 2 Ω, 1 Ω driving with output channels parallelization

• MOSFET power outputs allowing high output power capability:

Typ 4 x 30 W /4 Ω @ 14.4 V, 1 kHz THD = 10%

Typ 4 x 25 W /4 Ω @ 14.4 V, 1 kHz THD = 1%

Typ 4 x 50 W/2 Ω @ 14.4 V 1 kHz THD =10 %

Typ 4 x 80 W/4 Ω @ 25V V, 1 kHz THD =10 %

• I²C full configurability and diagnostic:

4 x Thermal warning and average junction temperature measurement on I²C (8 bits)

AC and DC diagnostic (independent of channel)

OCP protection scheme configurable (4 x OCP limit selectable)

Mute time configuration

DIM (digital impedance meter)

Feedback after filter configuration

• Capability to run complete diagnostic in play:

Short to GND/VCC

DC offset detector

• Extremely Low noise:

13 µV A-weighted; 20 kHz (high gain) typ

• Very low THD:

0.02% at 1 W 1 kHz on 4 and 2 Ω loads typ

0.08% 20-20 kHz (full audio band) on 4 and 2 Ω loads (1 W)

• CD/Diag pin (3 selectable CD thresholds)

• Synchronization output pin (only with TDM input stream, on I²Sdata2)

• Channel independent Mute/Play/Gain selection/Diagnostic

• Real Time current monitor

• Open Load in play

• Battery load dump compatible (40 V)

• Immune to pop/tick noise at turn on /off, battery variations (inside the operative range), during diagnostic

• EMI compliance evaluated according to CISPR25

• Legacy (no I²C mode)

• Integrated short circuit protections

• ESD integrated protections (2 kV HBM, 500 V / 750 V corner CDM)

• LQFP64 exposed pad up package

HFDA801A block diagram and pin description: