Class D audio amplifier module has small footprint and heatsink-free operation

Infineon Technologies AG now offers the MERUS two-channel, analog input, class D audio amplifier multichip module (MCM) MA5332MS. It is a powerful upgrade to its predecessor, providing the same or even higher output power than monolithic alternatives, with no heatsink and 50% less footprint. In the 100-400W/channel range, it is excellent for consumer products including home theaters in a box, subwoofers, soundbars, and mini-component systems. It is also ideal for professional applications such as active speakers, guitar amplifiers, active studio monitors, aftermarket car, and marine audio amplifiers.

Coming in a compact 7mm x 7mm2 42-pin QFN package, the device integrates a dual-channel PWM controller, a high-voltage gate driver, and four low R DS(ON) MOSFETs. Due to its very low R DS(on) class D output stage (24.4mOhm typical), it can provide 2 x 100W at 4-Ohm functioning absolutely heatsink-free or 2 x 200W at 4-Ohm with a small 8C/W heatsink. Compared to other single-chip solutions this is a comprehensive reduced size. It provides differential or single-ended input and multiple output configuration options, single-ended (2x SE), bridge-tied load, and parallel single-ended, utilising a single or split power supply. Providing an SE topology as an alternative to BTL provides for decreased bus capacitors and output low-pass filters.

As a highly-integrated MCM, it also incorporates protection circuitry for functions including over-current, over-temperature, and under-voltage protection with self-reset capability. This on-chip protection circuitry saves the time to create protection utilising external protection components. Furthermore, a new internal logic scheme to control soft-start operation offers a further reduction of click and pop noise. Based on its improved features, the device decreases BOM cost and thermal management concerns, offering more space for the industrial design and providing superior efficiency and low output distortion.