High power density Class D audio amplifier enables small footprint and heatsink-free operation

Article By : Infineon Technologies AG

Infineon's MERUS 2-channel, analog input, class D audio amplifier multichip module is a powerful upgrade to its predecessor.

Class D audio power amplifiers offer a combination of small size, low heat dissipation, high integration, and excellent sound quality. Unlocking the potential of its best-in-class power MOSFET technology, Infineon Technologies AG introduces the MERUS 2-channel, analog input, class D audio amplifier multichip module (MCM) MA5332MS. It is a powerful upgrade to its predecessor, offering the same or even higher output power than monolithic alternatives, without a heatsink and 50 percent less footprint.

In the 100-W/channel range, MA5332MS is ideal for consumer products including home theaters in a box, soundbars, subwoofers, and mini-component systems. It is also well suited for professional applications like active speakers, active studio monitors, guitar amplifiers, aftermarket car, and marine audio amplifiers.

Coming in a compact 7-by-7mm2 42-pin QFN package, MA5332MS integrates a dual-channel PWM controller, a high-voltage gate driver, and four low RDS(ON) MOSFETs. Τhanks to its very low RDS(on) class D output stage (24.4mΩ typical), it can deliver 2 x 100W at 4Ω operating absolutely heatsink-free or 2 x 200W at 4Ω with a small 8°C/W heatsink. Compared to other single-chip solutions this is a considerably reduced size. MA5332MS offers differential or single-ended input and multiple output configuration options, single-ended (2x SE), bridge-tied load (BTL), and parallel single-ended (PSE), using a single or split power supply. Enabling an SE topology as an alternative to BTL allows for reduced bus capacitors and output low-pass filters.

As a highly-integrated MCM, MA5332MS also integrates protection circuitry for functions such as over-current, over-temperature, and under-voltage protection with self-reset capability. This on-chip protection circuitry saves the time to design protection using external protection components. Additionally, a new internal logic scheme to control soft-start operation delivers a further reduction of click and pop noise. Based on its improved features, MA5332MS reduces BOM cost and thermal management concerns, providing more space for the industrial design and delivering superior efficiency and low output distortion.


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