Chipping in: new Texas Instruments DSP could be major breakthrough

Texas Instruments Inc. (TI) is "chipping in" to the auto industry's effort to simplify vehicles and their systems with a new digital signal processor (DSP). TI says it's the first such computer chip designed specifically to improve the performance, lower costs and reduce component count of systems driven by small motors.

The major benefits of the new chip, called the TMS320C240, or' C240 for short, would be the elimination of hydraulics and certain sensors in systems such as antilock braking, power steering, heating, ventilation and air conditioning (HVAC), active suspension control, and power windows and seats.

TI's 'C240 combines a signal processor and an integrated controller into a single chip. "It's changing the way motor systems are designed," says Gregg P. Bennett, manager of DSP marketing for the company's semiconductor group. "There's no chip like this any where."

The chip consists of a 20-MIPS (million instructions per second) processor CPU (compared to a standard 3-MIP 486 personal computer) that runs sophisticated motor-control formulas, a specialized motor-control circuit called an "event manager," plus a comprehensive group of motor-control peripherals, all on a single micropocessor. They also have the serial communications needed to plug into a multiplexed wiring system.

Even though system simplification is a major issue these days, hydraulics have been a mainstay of automotive control systems for a long time. Automaker and Tier 1 supplier reluctance to change to an all-electronic approach to small motor control might be overshadowed by the DSP's promised lower system cost and improved maintenance potential. Hydraulic subsystems are among the most maintenance-intensive parts of any vehicle.

Because the new DSP allows variable speed control, small motors can be connected directly to actuators that are presently controlled by variable-pressure hydraulic fluid.

Control systems that use the DSP in direct-drive electronics can be more reliable and efficient, says TI.

The new electronic microprocessor combines an extensive set of motor-control features with enough processing power to execute complex control equations needed for direct-drive electronic motor control of steering, braking and other subsystems.

Because the 'C240 DSP is an "intelligent" control processor, all electronic control systems under the chip's influence can be programmed to be more flexible than a hydraulic system. A power steering system, for example, can be programmed to offer drivers a variable steering profile at different speeds.

Texas Instruments says the first on-vehicle application of this chip likely will be on a future TRW Inc. power steering system, and will be used in the next generation of heating, ventilation and air-conditioning heat pumps by TEMIC Telefuken Microelectronic GmbH.

DSP electronic controls also may weigh less than their hydraulic predecessors, can be easier to install and maintain, and can occupy less physical space, placing fewer design constraints on automotive engineers. TI also says the new chip provides greater energy efficiency, reduced vibration and quieter operation.

The units will cost less than $10 in high-volume production (100,000 units), and the potential to eliminate mechanical parts offers significant opportunities to impact system cost, says the manufacturer. Also, each chip can control up to four small motors.

"In three to five years, there will be more electronically driven systems than hydraulic," predicts Mr. Bennett. "In 10 years, these chips will control 20% of the 10 billion small-motor market."