Dallas Texas Instruments Inc. (TI) claims its filter-free stereo Class-D audio power amplifier enables designers of cell phones to develop audio-rich products, while maximizing talk time and audio quality.
With about two-thirds lower quiescent current and 80% lower noise floor than its nearest competitor, the TPA2012D2 packs high efficiency and audio quality in a tiny package, according to TI. The 2.1-W stereo Class-D audio power amplifier is currently available in a 4mm x 4mm TQFN package and is sampling in TI's 2.0mm x 2.0mm WCSP. Applications include personal digital assistants (PDA), notebook computers, portable DVD players and other types of portable audio equipment.
In the new generation of TI Class-D amplifiers, the modulation scheme has been modified so that only a very short differential power pulse occurs to prevent “shoot-through” when there is no input signal. The diagram above shows the output waveforms of TI's filter-free Class-D modulation scheme.
“As consumer desire for audio-rich features like polyphonic ring-tones, MP3 music, streaming video with audio and 3-D surround-sound effects drives demand for stereo cell phones, manufacturers require two-channel, high-efficiency Class-D amplifiers to satisfy the demand without draining the battery,” said Art George, vice president of TI's high-performance linear business.
Operating from a 3.3-V supply, the TPA2012D2 draws 6 mA of supply current and has an A-weighted noise floor of 27μV rms, well below the level detectable to the human ear. This enables more audio features, clearer sound and efficient battery use. The device needs only two external components for correct operation and was designed for maximum system flexibility, offering four gain select options and independent channel shutdown.
Available now, the TPA2012D2 (TQFN) is priced at 95 cents in 1,000s. The WCSP version, which is sampling now, will sell for $1.05 in same quantities. Production quantities for the WCSP are slated for March. An evaluation module will be available next month.
For more information, please call 1-800-477-8924 or visit: www.ti.com