This article focuses on the use of D-class audio amplifiers in automotive infotainment systems. D-class amplifiers typically operate at around 400kHz when starting and shutting down the amplifier. However, the TPA6404-Q1 D-class amplifier design utilizes a higher 2.1MHz switching frequency, which significantly reduces the inductance value of the output filter.

The 2.1MHz design, which utilizes newer 3.3μH metal alloy inductors (in contrast to the larger 10μH/8.2μH inductors required for a 400kHz amplifier), allows all eight inductors used in a four-channel solution to fit into the same space as a single 8.2μH inductor.

Another key feature of the TPA6404-Q1 is its "flow-through" audio signal design, which helps to achieve a smaller four-channel amplifier solution size. The analog input signal enters the amplifier device on one side, and the amplification of the audio signal occurs on the opposite side of the device, where the signal flows into an external output filter.

The combination of the metal alloy 3.3μH inductors and the flow-through design enables the TPA6404-Q1 to achieve the smallest four-channel automotive D-class amplifier size in the industry, with a solution size of only 4.5cm2 (including the amplifier and all necessary passive components).

If you are looking to reduce the overall solution size and the heat generated by entry-level infotainment audio host systems, then the TPA6404-Q1 2.1-MHz D-class amplifier can provide more help. To jumpstart your design, you can also use the TPA6404-Q1 evaluation module (EVM) and design files, schematics, and layout guidelines to shorten your development time. 

We hope this information on the use of D-class audio amplifiers in automotive infotainment systems is helpful to you.