DSPs Power Down

Texas Instruments is taking aim at the growing push for low-power portable products, rolling out design tools that provide a methodology for measuring real-world power consumption as well as three DSP chips designed to trim that consumption.

The three new members of TI's C5000 line claim to be the lowest power DSPs around, with operating power as low as 77 mW per MHz and standby power of only 0.12 mW (http://rbi.ims.ca/3852-516). That sleep mode power rating is 114 times less than competitive products, spokesmen say. "In many instances, 90-95 percent of the time you are in standby. Full operating power can be needed as little as 4 percent of the time," says Leon Adams, worldwide manager, DSP products marketing.

When the chips leave the standby mode, only the necessary circuits are powered up. The ICs hold up to 256 Kbytes of RAM, making it possible to access memory without powering up external memories that often consume more power. CPU speed is also scaled up or down so that the CPU isn't consuming any more power than necessary for a given task, Adams adds. Pricing for the chips starts at $7.50 in quantities of 10,000.

TI's ExpressDSP Power Design Package has four elements including a power scaling library and a real-time power management kernel. The power scaling library lets design engineers control runtime frequency and lets them adjust these scaling operations to accommodate peripheral changes. The kernel works closely with the DSP/BIOS to automatically implement power-saving techniques, including managing clock domains and sleep states.

Another power measurement tool works with National Instruments software to simplify measurement of total energy and maximum/average power and peripheral usage. The final power-planning tool includes a spreadsheet for checking trial configurations.

Riding cell phones

Underscoring the importance of power conservation, a full 62 percent of all DSP shipments went into cell phones during the first four months of 2004, according to Forward Concepts of Tempe, AZ (http://rbi.ims.ca/3852-519). Another 9 percent went into consumer products, where portable products such as digital cameras are growing rapidly.

DSPs are critical for multimedia applications and connectivity, two of the driving trends throughout the electronics industry. In cell phones, they're used to add graphics and camera capabilities, and expand the variety and quality of ring tones.

Cell phone usage continues largely unabated. In the first quarter, shipments hit 153 million, the best quarterly figure in history according to Gartner Inc. of Stamford, CT (http://rbi.ims.ca/3852-520). Gartner feels that record level will continue throughout this year, so more than 600 million cell phones will ship in 2004.

Despite the sharp rise in cell phone shipments, DSP sales were down 4 percent during the first quarter compared to the fourth quarter. However, that's sexpected to be a momentary blip, and the slumping figure is still 20 percent higher than comparable 2003 figures. Programmable DSPs will have a compound annual growth rate of 22 percent through 2008, according to Forward Concepts.