Class-G headphone amplifiers from Texas Instruments

31st March 2009

ES Admin

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Users of music phones and MP3 players can benefit from dramatically extended music playback time enabled by two new 25-mW Class-G, DirectPath stereo headphone amplifiers from Texas Instruments, which adjust their voltage supplies to the audio signal to minimize power dissipation. In a standalone Lithium-Ion battery test between TI’s Class-G technology and a competing ground-referenced Class-AB device, the TPA6140A2 and TPA6141A2 reduced power consumption by 30 percent.

The amplifiers improve system-level music playback time by 20 percent over Class-AB technology in the best-in-class music phones shipping today.

“Consumers traveling from Dallas to Delhi or from San Francisco to Shanghai want to listen to their MP3s for the duration of the flight without worrying whether they have enough battery life left to make a call when they land,” said Art George, senior vice president of TI’s High-Performance Analog business unit. “Devices like the TPA6140A2 and TPA6141A2 save critical battery life to make this scenario a reality.”

Other key features significantly improve sound quality. The amplifiers feature TI’s field-proven DirectPath technology, which eliminates the need for large DC-blocking capacitors at the amplifier outputs to give designers additional board space and allow consumers to enjoy greater low-frequency audio fidelity. In addition, the TPA6140A2 and TPA6141A2 include built-in pop suppression circuitry, which completely eliminates disturbing pop noise when the amplifier powers on, to enable a seamless audio experience. Power supply rejection of greater than 100 dB and differential inputs improve noise rejection, while 100-dB signal-to-noise ratio (SNR) improves the signal quality to deliver crystal clear audio.