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Portable consumer electronic device manufacturers are challenged to develop cost-efficient, high-performance, feature-rich audio solutions with longer battery life. At the same time, manufacturers are forced to reduce development time in order to be the first to introduce new products in the market. With the recent development of ultra-low power codecs with embedded mini-DSPs and powerful graphical programming tools, manufacturers can now meet these complex requirements.
The ultra-low power consumption and processing capabilities of these devices provide low-power audio solutions for systems requiring separate codecs, as well as for systems that incorporate baseband or application processor chips with imbedded analog I/O. The graphical programming environments and extensive software libraries permit applications to be developed in a fraction of the time required by conventional programming environments.
With respect to low-power operation, many of these new generation ultra-low power codecs can operate the analog and digital cores from a single 1.5- to 1.8-V supply. It's possible to further reduce power by operating the digital cores at voltages as low as 1.26V. Many devices have low-power operating modes. However, additional power-tuning options enable designers to tailor their power based upon the individual configuration and processing options used in the record and playback paths. This allows designers to minimize power tuning to be dynamically optimized based upon the number of input and output channels, output drive requirements, sample rate, desired signal-to-noise-ratio (SNR) performance for the input and output, and processing features used.
With this capability, as shown in Figure 1, the codec power consumption can be tuned to provide optimum performance for different audio reproduction modes (progress, messaging tones, voice communication and music reproduction), different I/O configurations (handset versus headset operation), and different signal processing requirements (low-noise versus high-noise communication environments). Power tuning controls permit the additional configuration options for conversion-less analog bypass operation modes, PLL vs. PLL-less operation, or class D versus AB headphone drive configurations. These configuration controls are managed through an I2C or SPI bus.
Figure 1. Power consumption increases as SNR and voltage supply increases. Users can tune the power consumption to their application and system requirements
Power tuning can make a significant difference in the battery life of a portable audio device. The low-power operational mode allows some of the ultra-low power codes with signal processing to have power consumption under 5mW for progress / messaging tones, under 7mW when supporting voice communications at 8- or 16kHz, and under 10mW when supporting the highest quality 44.1kHz stereo headphone music reproduction.
The combination of ultra-low power data conversion and low-power signal processing in one chip offers significant power-saving opportunities in conventional systems architectures that include an applications processor and codec. In these architectures, the ultra-low power codec can perform some or all of the audio processing functions of the applications processor.
Systems with baseband or application processor chips have analog input and/or output capabilities. Codecs with signal processing capabilities provide a low-cost, short development cycle solution to incorporate additional features or functions, without reprogramming or replacing the existing baseband or application processor.
One of the powerful tools for longer battery life is the new ultra-low power codec with embedded mini-DSP. These devices and their powerful graphical programming tools provide low-power audio solutions for a variety of portable audio processing and communication system architectures. Power consumption is as low as 2.4mW in stereo playback. It is programmed using a graphical software environment, which also simplifies programming for the manufacturer.
The portable consumer electronics marketplace is very competitive and fast-paced. Quick time-to-market and very low-power consumption empower manufacturers to reduce their design cycle while creating differentiated products. Very low-power audio converters with integrated DSP and a graphical software development environment to quickly program it are competitive advantages.
For more information on the TLV320AIC3254 visit: PurePath Studio
About the Authors
Luca Cacioli is Portable Audio Marketing Manager for portable audio converters at Texas Instruments. He received his BSEE/MSEE from Universita' di Firenze, Florence, Italy, and his MBA from Southern Methodist University (SMU), Dallas, TX. Luca also enjoys soccer and traveling. He can be reached at: ti_lucacacioli@list.ti.com.
David Zaucha is the Software Development Manager for portable audio converters at Texas Instruments. He received his BSEE from University of Massachusetts, Amherst, Massachusetts. and his MSEE from University of Rochester, Rochester, New York. David also enjoys photography. He can be reached at: ti_davidzaucha@list.ti.com
For more information on battery life on Mobile Handset DesignLine, see: Battery Life
For more information on audio codecs on Mobile Handset DesignLine, see: Audio Codec
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