Background information: automotive applications

The automotive market offers a particular challenge to the semiconductor industry by the severity of its price/performance demands. Although the semiconductor content accounts for less than 1% of the cost of a new car, high volumes and intense competition make the car industry extremely price-conscious.

At the same time, the automotive environment is an especially hostile one: depending on proximity to the engine, operating environment temperatures can range from -40ºC in a Scandinavian winter to +55ºC in the desert, while high energy transients and accidental battery reversals are not uncommon. Moreover, even minor electronic malfunctions caused by semiconductor failure may severely inconvenience the car owner as roadside repair is not usually practical.

In effect, the automotive market demands almost military quality and reliability at commercial prices, across a broad range of products that includes discrete devices, memories, MCUs, smartpower ICs and DSPs.

Success in the automotive market therefore requires three essential ingredients:
(1) a broad platform of advanced technologies, especially in mixed signal circuits, smartpower and non-volatile memories;
(2) an unswerving commitment to quality;
(3) a thorough understanding of the automotive market gained through close collaboration with leading customers.

SGS-THOMSON has demonstrable strength in each of these areas; our technology portfolio is second to none, the numerous quality awards we have won from automotive manufacturers such as Chrysler and Ford underline our total dedication to quality and our track record in supplying over a quarter of a billion dedicated ICs to the automotive industry speaks for itself.

Today, the automotive industry is a major growth area for semiconductors and the semiconductor content of cars increases every year. Electronic techniques can bring increased reliability, but this is only the beginning. Safety is of great importance, with ABS, airbags and other features becoming increasingly common. Equally, new legislation to limit exhaust emissions and customer demand for additional features, such as electrically operated windows, mirrors, sunroofs and seats, have resulted in the greater penetration of semiconductors.

In terms of semiconductor products, this means an increase in the use of all types of component, from discrete devices to DSPs. In the longer term, emerging techniques such as fuzzy logic and neural networks may find important roles in the automotive market; in the shorter term, however, the areas of greatest growth will be analogue/linear ICs (including power ICs) and microcontrollers. In particular, the replacement of cumbersome wiring harnesses by multiplexed wiring will lead to a major increase in the number of MCUs and power ICs used in new vehicles.

The arguments in favour of multiplexed wiring are simple and universally accepted: multiplex wiring reduces the volume and weight of the wiring harness, improves electrical reliability and facilitates maintenance. These benefits are achieved by replacing point-to-point wiring by a number of intelligent nodes connected by a single bus and communicating via a standard protocol. Intelligent power devices can then be used to control motors and solenoids in response to commands transmitted over the bus.

A number of different bus protocols have been proposed, of which the best known are the SAE's J1850 (adopted by Ford and GM in the USA), CAN (Bosch) and VAN (PSA, Renault). Because of the lack of a single standard protocol, it makes sense to include bus interface and diagnostic circuitry in the smartpower devices but to handle the bus protocol externally, preferably in software.

SGS-THOMSON is supporting all three of the above protocols. For J1850 and VAN, we offer software simulations running on the ST9 microcontroller while the ST10 family of 16-bit microcontrollers includes a device with an integral CAN peripheral, as well as a 16-channel 10-bit ADC and many other features that make it ideal for automotive applications.

Smartpower

Smartpower is a generic term that covers a variety of technologies, vertical as well as lateral, and both kinds have important roles to play in the automotive market. Vertical technologies, of which our VIPower processes are outstanding examples, offer the highest voltage and current capability while lateral technologies such as BCD provide the greatest architectural flexibility and the greatest scope for digital control.

The high voltage capability of VIPower devices make them particularly suitable for use as ignition drivers. The VB921ZV, for example, integrates a power trilington (3-transistor bipolar Darlington), a collector voltage clamp protection circuit and internally compensated coil current limitation circuitry into a single chip that is available in a standard 3-pin transistor package, allowing direct replacement of conventional ignition driver transistors.

The development and growth of the market for intelligent ignition devices has been a major success story for SGS-THOMSON, with 1in 2 cars in Europe now using SGS-THOMSON electronic ignition components. Other VIPower products with important automotive applications include intelligent high side drivers such as the VND05/10B and the OMNIFETs, which are rugged power MOSFETs with integrated current limitation, overtemperature protection and overvoltage clamping circuits. These functions are user-transparent, allowing OMNIFETs to be housed in standard three-pin packages and used as drop-in replacements for conventional power MOSFETs

BCD (Bipolar-CMOS-DMOS) technology has been used to build many different automotive circuits such as the L9946, a device that integrates all of the control functions and power circuits needed in the electronic external rear-view mirror unit now being adopted for high end cars. The L9946 is controlled by an MCU and drives directly the two motors used for mirror orientation, the motor that "folds" the mirror for manoeuvring and the demister heating element.

BCD technology is now in its third generation, with a CMOS packing density of 5000 transistors/sq.mm - a threefold increase over the previous generation. This means that it is now economically feasible to integrate a complete 8-bit MCU core and its peripherals, along with EEPROM or EPROM memory, on a smartpower chip. This 'supersmart' power technology has many applications in the automotive market, especially in the field of intelligent actuators.

For engine management and other automotive applications, the combination of FLASH memory and a powerful MCU core is very attractive. This technique was pioneered by SGS-THOMSON with the introduction of the ST10F166, the world's first MCU with embedded FLASH memory. The in-circuit erasability of the FLASH memory is ideal for control applications requiring code updates or parameter modifications. One example is the reprogramming of engine control in ageing cars.

FLASH technology will play an increasingly important role in the cars of the future, both as standard memory products - we are currently delivering FLASH memories to major car manufacturers - and integrated onto microcontrollers.

Technology platform

Our success in the automotive market illustrates the importance of having a broad platform of advanced technologies. For example, the L9340 fuel injector driver and the VB02x smart ignition transistors are built with different smartpower technologies. The L9340 uses BCD2 technology and the VB02x uses VIPower M1.

These examples by no means exhaust the range of technologies that SGS-THOMSON designers can employ to solve the problems that the automotive industry brings to us; others include power BiCMOS (ideal for high power, low distortion audio amplifier, as well as non-volatile memory technologies such as FLASH and EEPROM and smartcard ICs and leading edge ASIC technologies.

Memory technology has many different applications in the automotive field, from radio tuning and anti-theft devices (which use EEPROM or special secure EEPROM) to emerging applications such as automatic toll systems (smartcard ICs) and in-car navigation systems (FLASH or OTP).

In the custom and semicustom arena, high performance digital and mixed signal technologies are available. In addition, digital cores are developed using VHDL techniques to minimise customers' time to market.

Even relatively simple functions like transient protection can be greatly enhanced by the use of innovative technology. For example, the RBO08-40 and RBO40-40 Application Specific Discretes (ASDs) are 3-terminal devices that contain a series diode for reverse battery protection, a bidirectional Transil diode to clamp negative overvoltages and a power Transil that protects against load dumps - high energy transients that occur when the battery is disconnected while the alternator is generating.

The key advantage of the ASD concept is that the benefits of integration, such as improved reliability, smaller PCB area and reduced assembly costs, are achieved without sacrificing the major advantage of discrete technology, namely high surge current capability. This is because SGS-THOMSON uses a proprietary bipolar technology in which both sides of the wafer are masked and processed, allowing the surge currents to flow vertically.

Conclusion

Although the automotive market is a particularly demanding one, it is also highly rewarding for those companies that can establish and maintain market leadership. SGS-THOMSON's success in this highly competitive market is due to our excellent technology, our dedication to quality and the unrivalled knowledge of the automotive market that we have developed through alliances with key customers. Through these alliances, SGS-THOMSON and its customers are delivering more reliable, safer, cleaner and more enjoyable cars.

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