100 watts of audio from 1.5 volts

Audium Semiconductor has launched an audio power amplifier IC which, at normal listening levels, is 20 times more efficient than competing devices, such as Class D amplifiers, without compromising audio quality. The AS1001 operates from a nominal 1.5 V power supply and delivers 100 W peak power output. The amplifier is so efficient that battery-powered amplified loudspeakers can run for up to 10 months on a set of four ‘C’ batteries, playing for three hours per day.

The amplifier also enables the development of smaller, cooler, mains-powered audio equipment, with fewer heat sinks. Applications include totally wireless speakers, home theatre surround sound speakers and battery-powered travel speakers. Future Audium ICs will support MP3 docking stations and USB powered speakers.

The AS1001 architecture uses patented techniques to minimise both fixed power losses and output-dependant variable power losses. The modulation scheme uses low switching rates to minimise switching losses. Power rail switching means that the amplifier operates efficiently from a low voltage rail most of the time, with a DC-DC boost converter driving higher voltage transistors on extreme audio peaks.

Targeting battery powered applications; the AS1001 is a single 64QFN package and operates directly from a 0.8V – 1.8V supply (compatible with, for example, alkaline primary cells and Ni-MH secondary cells). Samples are available now.