'C240 DSP lets designers eliminate hydraulics

In this Issue

New 32-bit ARM-based microcontroller

'C240 DSP lets designers eliminate hydraulics

PowerFLEX packaging designed for auto needs

Automotive Solutions from Texas Instruments

Value engineering in today's cars

Silicon integration: panacea or problem?

Flash memory devices

DSP steers auto designers to eliminate hydraulics

Automotive hydraulic subsystems could soon be eliminated, thanks to a powerful new microprocessor from Texas Instruments. The TMS320C240 combines an extensive set of motor control features with enough processing power to execute complex control equations needed for direct-drive electric motor control of steering, braking and other automotive subsystems.

TMS320C240 features

T320C2xLP 16-bit, fixed-point DSP core

20 MIPS DSP core

Event manager

Supports up to 12 pulse-width modulation (PWM) outputs with PWM and I/O features that include three up/down timers, nine comparators, dead-band generation logic, and a state-space vector PWM generator.
Four capture inputs, two of which can serve as direct inputs for optical-encoder quadrature pulses.
Dual on-chip, 10-bit analog-to-digital converters provide precise conversion of information such as current or voltage feedback.

Two serial interfaces

Two 10-bit A/D converters

28 bits of digital I/O

Watchdog timer

16K words of flash memory ('F240 version)

A revolution in automotive control

Because TI's TMS320C240 DSP allows variable speed control, inexpensive brushless motors can be connected directly to actuators that are today controlled via variable pressure hydraulic fluid. Hydraulic subsystems have long been mainstays of automotive control systems, but their numerous disadvantages make their elimination from the automotive environment desirable. Control systems that use the 'C240 in direct-drive electronics can be more reliable and cleaner, requiring no highly pressurized hydraulic fluid and doing away with the engine load incurred when pressure must be delivered to hydraulic systems. DSP-enabled electronic controls may also weigh far less than their hydraulic predecessors, can be easier to install and maintain, and can occupy less physical space. This places fewer design constraints on automotive engineers.

For example, a 'C240-based electronic power steering subsystem can be programmed to exhibit a variable steering profile, with increased steering boost at very low speeds, and tight, sports car-like response at highway speeds. Electronic brake controllers use the 'C240 to directly drive high-torque switched reluctance motors, allowing a localized, intelligent control loop for advanced anti-lock brake systems. Other areas where the intelligence of the 'C240 can be applied include active suspension control, and window motors programmed to detect current overload, stopping the closure of a window whose travel might otherwise inadvertently injure a passenger.

Samples available in 1997

The TMS320C240 will be priced at less than $10 in high-volume production (100,000 units). Prices for future, reduced-function 'C24x series configurations at high volume are expected to be as low as $5. An identical configuration with on-chip flash memory instead of ROM, the TMS320F240, will be the first device available to allow easy system prototyping and system programmability. Flash versions ('F240) will be priced slightly higher than ROM versions ('C240), and are scheduled to sample in the first quarter of 1997, with ramp-to-volume production scheduled for late 1997. The 'C240 is scheduled to ship in volume production in the first quarter of 1998.