ST's new amplifiers bring superior sound and sleek style to advanced audio systems

GENEVA, SWITZERLAND: STMicroelectronics has introduced a high-performance, analog class-D audio amplifier with best-in-class power density. This achievement will allow equipment manufacturers to combine superior audio quality with a small form factor in next-generation home and professional sound systems and active-speaker applications.

To maximize the speaker output power, sound-system manufacturers require high-efficiency amplifiers capable of driving speakers at low impedances of 2 or 3 ohms, which creates a challenge by increasing device sizes. ST designers have addressed this problem by managing to pack 320W of total output power – 160W on each channel - on an area of 100 mm2, giving ST’s newest analog audio class-D amplifier a 20 percent power-density advantage over existing solutions on the market.

The device’s high-current capability not only delivers high output power, but also enables the design of platform solutions where the speaker impedance can be simply changed - from 8 down to 2 ohms - without any power or current limitation.

ST’s newest amplifier also integrates a host of features that increase audio quality in the final application, including built-in suppression of pop/click noises, standby and mute functionality, and balanced input for best TDMA (Time Division Multiple Access) noise rejection. The device embeds smart current protection, which recognizes when the speaker requires a peak of current for a specific frequency range and automatically prevents any interruptions in the sound flow.

The TDA7498E amplifier offers flexible audio-system configuration, in both stereo and mono modes, and also includes the mono parallel feature for driving the subwoofer/woofer channel in 2.1 sound set-ups. The device exhibits a signal-to-noise ratio of 100dB and provides four selectable, fixed-gain settings at 23.8dB, 29.8dB, 33.3dB and 35.8dB.

ST’s TDA7498E dual-BTL (Bridge Tied Load) class-D audio amplifier with a single power supply is sampling now and volume production is scheduled for February 2012, with unit pricing at $6 for volumes in the range of 1,000 pieces.