Class-D audio amplifier exhibits power density of 3.2-W/mm-square
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 320 W of total output power – 160 W on each channel – on an area of 100 mm2, giving ST’s newest analog audio class-D amplifier a 20% 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 23.8 dB, 29.8 dB, 33.3 dB and 35.8 dB.
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.
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