PORTLAND, Ore. — Micro-electromechanical systems (MEMS) are just getting smaller and smaller as well as higher and higher performance. Take STMicroelectronics' new 6-axis IMU designed specifically to be qualified for the Automotive Electronics Council's A-100 stress-test qualification for integrated circuits. In addition to being low-noise with improved output resolution, the 6-axis A-100 qualified IMU also claims the title of the world's smallest, measuring just 3x3x1.1 millimeters.
The claim holds for now: Most equivalent products from competitors are at 4x4 mm. "The increasing interest in automotive telematics and navigation is driving the need for better performance and smaller size,” said Anton Hofmeister, group vice president and general manager, Custom MEMS Division. Combining an accurate accelerometer and gyroscope on a single die, "is a strong statement of our expertise,” he told us.
Automotive sensors, however, has not been ST's sweet spot. Consumer applications have been the company's strength, so it makes sense that its push into automotive would start with non-critical applications, which it has already been producing for automobiles since 2011, according to Jeremie Bouchaud, senior director, MEMS and Sensors at IHS. The new ASM330LXH combo MEMS sensor is designed for non-critical automotive applications like navigation and telematics.
STMicroelectronics is pushing into the automotive market with what it claims is the world's smallest AEC A-100 qualified 6-axis combo accelerometer and gyroscope.
Bouchaud told EE Times:
ST dominates the MEMS market for consumer and mobile applications (21% revenue share in 2013) and started leveraging its position in consumer MEMS to expand in automotive MEMS in 2011. Its share is still very small in automotive (0.7% in 2013) but it’s a newcomer established suppliers such as Bosch, Freescale, ADI, and Murata (former VTI) must take seriously.
ST logically started to enter the MEMS market for automotive with non-safety critical applications with accelerometers in 2011 and with gyroscopes in 2012. The ASM330LXH combo is also targeting non-safety applications, but there is no doubt that ST will also target the booming market of combo for safety applications for electronic-stability control and rollover. One should note that ST already made inroads in safety applications with accelerometers for airbags since the end of 2013.
ST chose its THELMA (Thick Epitaxial Layer for Micro-Gyroscopes and Accelerometers) process to aid in integrating acceleration and angular-rate (gyroscope) onto the same piece of silicon. Not only does THELMA assure perfect data synchronization between the two sensors' outputs, according to ST, but it also simplifies the installation of the 6-axis combo sensor on the printed-circuit board (PCB) by original equipment manufacturers, according to Bouchaud:
The main advantage of offering a 6-axis IMU in automotive is the high flexibility it offers the automotive Tier 1 in the assembly. The PCB is not always vertical or horizontal; it is often at an angle. We saw in our teardowns sometimes complex constructions in the assembly of the sensor to compensate for the angle of the PCB when a single-axis gyroscope is used, for instance. With such a 6-axis combo sensor the assembly and integration of the sensor is considerably eased.
ST says it is targeting the ASM330LXH IMU at in-dash car-navigation applications, allowing accurate dead-reckoning algorithms to keep the position of the car updated even when GPS signals are blocked by tunnels, tall buildings, or parking garages. It is also targeting telematics applications.
— R. Colin Johnson, Advanced Technology Editor, EE Times