Motor DSPs debut

Tempe, AZ —Responding to a need for greater math processing capabilities, three of the world's biggest chip makers have unveiled new digital signal processors (DSPs) for motor control applications.

Motorola predicts that DSP usage in motor controllers will jump from 5 million units in 1999 to 70 million in 2003.

The new motor control products, which are all said to be among the fastest on the market, are part of a growing trend among semiconductor makers to provide speedier DSPs for embedded applications. Motorola and Texas Instruments (Dallas, TX) say that their new DSPs will operate at maximum speeds of 40 million instructions per second (MIPS)—about 30% faster than competing motor controllers. Analog Devices (Wilmington, MA) says its DSP will process data several times faster than those, ultimately reaching speeds of 150 MIPS.

Makers of the new DSPs say that several forces are conspiring to drive the technology forward. Among them: a governmental effort toward more energy efficient appliances, a proliferation of electric motors in automobiles, and a drive toward greater precision in those vehicles. For these reasons, experts say they expect motor DSP usage to skyrocket during the next three years.

DSPs meet the needs of such applications because they offer greater number-crunching ability than conventional microcontrollers, thus enabling them to take on tasks such as variable speed operation. Used in home appliances, such as refrigerators and air conditioners, variable speed motor operation could help reduce energy consumption. "On the white goods side, we've been seeing a legislative push for reduced energy consumption for several years," says Debbie Drysdale, vice president and general manager of Motorola's DSP Standard Products Division.

In the industrial sector, Texas Instruments engineers say that speedier DSPs will enable closed loop operation of motors and drives without the need for sensors. Using the extra computing power of a DSP, a drive alone could calculate the speed and position of a motor's rotor by monitoring the electrical current in the windings.

Faster DSPs could also help in industrial applications by enabling simpler control of motor torque. "Most of today's microcontrollers are fast enough to monitor and control motor positions," says Tom Bullock of Industrial Controls Consulting (Fond du Lac, WI). "But torque loops are another matter. There, processing speed becomes very important." Torque measurement is critical in automated machine tools and assembly equipment, Bullock said.

The engineers see the automotive market increasing its use of DSPs. There, they note that the burgeoning use of motors—many vehicles now employ between 80 and 100 apiece—is creating a need for faster devices that can interface with network buses.

DSP makers are gearing up for the higher performance needs they foresee. Texas Instruments says its will continue to build on its current DSP platform and plans to reach 400 MIPS performance by the end of this year. "The design for 400 MIPS is already in place," says Christopher Chene, worldwide digital control systems marketing manager for Texas Instruments.