Ai interview – Bernd Gessner, General Manager Automotive, austriamicrosystems AG.

austriamicrosystems’ products are used in the automotive as well as the medical, communications and industrial sectors. The company’s manufacturing facilities include a 200mm (8″) wafer fab in Austria and test centers in Austria and the Philippines; the company also has sales offices around the globe. The company splits its automotive activities into two broad groups: sensors and sensor interfaces, which includes a wide portfolio of magnetic encoders and ASICs in-vehicle networking group, which provides battery management solutions and system basis chips that contain power management circuits as well as LIN, CAN and FlexRay bus drivers.

austriamicrosystems also focuses on solutions for electric and hybrid cars alongside its groundbreaking solutions for conventional vehicles, where it offers high-side and low-side battery management solutions for lead-acid cars.

Some time ago, the company expanded its magnetic rotary encoder portfolio with the AS5163 – a magnetic encoder IC which meets the toughest automotive requirements for overvoltage and reverse polarity protection. The AS5163 is the first magnetic rotary encoder IC specifically designed to satisfy stringent automotive requirements in angle sensing applications where robust IC protection is essential.

austriamicrosystems’ magnetic encoder IC AS5163 incorporates both +27 Volt overvoltage protection and -18 Volt reverse polarity at the supply pins. The AS5163 also features an intelligent monitoring function to protect it from damage in short-circuit conditions. This makes the encoder IC ideally suited for automotive applications, such as throttle or gas-pedal systems.

“The AS5163 is perfectly positioned to meet the challenges of device protection and system reliability in the automotive industry,” comments Andreas Pfingstl, Product Manager Automotive Encoders at austriamicrosystems. “When developing this device, we put special emphasis on ease of use and low cost. The AS5163 offers a single-wire interface and, together with its robust protection features, allows system designers to meet their performance and reliability requirements, while optimizing system cost.”

The AS5163’s single-wire pin can be configured either as a 14-bit digital, 12-bit PWM or ratiometric analog output. In addition, the IC can be customized by the user to cover any system-specific angle range. The programming of the desired angle range is achieved by simply setting a start and end position of the rotational movement. This feature makes the AS5163 extremely flexible and easy to use in a variety of automotive angle-sensing applications.

Another new product from austriamicrosystems is the AS5165, a robust, high-resolution, contactless magnetic angle sensor with an SAE SENT J2716 interface. With this new high-resolution magnetic rotary sensor offering best-in-class protection features for reliable operation in harsh automotive environments and a SENT J2716 interface for simple transmission of high-resolution sensor information, austriamicrosystems is now able to provide different interfaces for different customer requirements.

Automotive Industries spoke to Bernd Gessner, General Manager Automotive, austriamicrosystems AG.

AI: Magnetic Encoders is one of the focus segments at austriamicrosystems. Could you explain why you are concentrating on this area and what the benefits are compared to other technologies?

Rotary encoders from austriamicrosystems are designed to replace dust-sensitive optical encoders, expensive resolvers and unreliable potentiometers. This kind of encoder helps customers because it offers a non-contact motion-measurement system. Magnetic rotary encoders provide very high reliability, are cost efficient and improve the overall performance of the sensing system compared to existing solutions.
For safety critical applications such as steering or throttle control, redundancy is a must-have. austriamicrosystems is able to provide such a redundant sensing solution, based on a stacked-die approach.

This failsafe magnetic angular encoder with built-in redundancy includes two sensors in one package, identical and electrically isolated from each other. Both the dual-die and single-die solutions are fully qualified to AEC-Q100 with an operating ambient temperature range from -40°C up to 150°C.

AI: Could you tell us what is the secret of your success in Magnetic Encoders and where you are positioned compared to competition?

Our latest generation of encoders is more robust than any other motion-sensing product on the market. There are a number of reasons for this. The platform offers best-in-class device protection. Besides overvoltage and reverse polarity protection, they offer a continuous monitoring to protect the IC against damage arising from a short circuit. Based on our patented differential approach, all our magnetic encoders are insensitive to stray magnetic fields without the need for any shielding, which helps to reduce bill of materials and manufacturing costs. When packaged in a dual-die solution, we also provide full redundancy for safety-critical applications. Furthermore we have the ability to modify encoders quickly to meet special requirements .

AI: On what application are you focusing and what are the reasons for focusing on these applications?

Magnetic encoders can be used in virtually every application where angles or distances need to be measured. Currently, austriamicrosystems’ automotive magnetic rotary encoders are strongly represented in module applications such as gearboxes, steering, brushless DC motor control as well as in throttle and gas pedal solutions. Steering and pedals are safety-critical applications. To fulfill the toughest automotive requirements, redundancy is essential. BLDC motor control applications on the other hand require high-speed measurement and special features to support the motor commutation. Each of the company’s target applications requires different key features for programming and diagnostics. With its wide portfolio of rotary encoders austriamicrosystems is able to provide the right solution to its end customers. Customers rely on austriamicrosystems’ encoder solutions because of their robustness, their insensitivity to external influences and their accurate performance.

AI: Could you tell us what’s next at austriamicrosystems as far as Magnetic Encoders go? What can we expect in the future?

We will of course strengthen our current portfolio. New interfaces, higher speed, higher resolution and lower power consumption are the goals for the next couple of years.

In addition we will introduce our first 3D Hall encoder in 2011, a technology that is complementary to our existing portfolio and that will open additional application areas to us.

AI: You mention a 3D Hall Encoder. Could you explain in detail what the benefits of this new approach are and what are the differences to common Magnetic Encoders?

3D Hall encoders use a different technology. Instead of measuring only one direction of the magnetic field we are measuring now all 3 axes. So with the right algorithm we can use the 3 dimensions to do linear measurement, off-axis measurement (where the magnet does not have to be on top of the IC) and joystick applications. With the 3 dimensions we can do whatever is required from the application with the same sensor array by just changing the post-processing.

One thing is common for all our products though: robustness, reliability and long-term source of supply