Automotive designs now use more Hall-effect magnetic sensors like the AS5245 from austriamicrosystems to ensure safe and efficient operation.
ARM processors and sensors typically conjure up slick consumer electronics products such as smart phones, tablets, and game consoles. But they’re in the cars we drive, too, and they’re having a larger impact on the auto industry.
Consider ARM processors. Analysis from Semicast shows that ARM maintained its position as the leading architecture for 32-bit embedded processors in the automotive sector in 2011, ahead of Power Architecture, SH, TriCore, and V850. The data also suggests that ARM’s lead in this sector is set to increase significantly over the next five years.
ARM’s Broad Reach
Why is this so? According to Semicast, ARM’s presence is now established in most of the main systems in the vehicle, including the airbag, body electronics, braking, driver assistance, electric power steering, infotainment, instrument clusters, radio, navigation systems, satellite radio receivers, and embedded telematics.
Semicast identifies this diverse application base as the key factor behind the higher revenue growth forecast for ARM over all other architectures in the automotive sector in the medium term, as diverse suppliers work together to drive forward ARM’s position in the vehicle.
As in consumer electronics and other sectors, ARM’s leadership position in the automotive market comes from multiple design wins across the spectrum of its silicon partners. For example, ARM has secured design wins in applications processors from Freescale, Nvidia, and Texas Instruments; baseband processors from Qualcomm, ST-Ericsson, and Sierra Wireless; Bluetooth/Wi-Fi communications controllers from Broadcom and Marvell; and simple M0/M3 MCUs from Fujitsu, NXP, and STMicroelectronics.
“Semicast estimates an average of three ARM-powered chips in every light vehicle produced worldwide in 2011 and forecasts that this will increase to seven in 2016,” said Colin Barnden, principal analyst at Semicast.
Magnetic Sensors Attract Motors
On the sensor front, magnetic sensors are primed for growth, due to their ability to improve car safety, convenience, and fuel efficiency. According to IHS iSuppli, revenue for these sensors is expected to expand by nearly 40% this year to $160.3 million, up from $116.0 million in 2011.
“Driving a car makes use of as many as 100 small motors, performing tasks ranging from enabling the power steering to actuating the fans in the heating, ventilation, and air conditioning (HVAC) system,” said Richard Dixon, senior analyst for MEMS & sensors at IHS.
“These motors often employ magnetic sensors to ensure their safe and efficient operation. Because of this, magnetic sensors have attained widespread and fast-growing usage in the automotive segment,” he added (see the figure).
According to IHS iSuppli, the automotive industry accounts for half of all semiconductor magnetic sensor market revenue. Each low-end to midrange car, for instance, incorporates more than 10 electric motors on average, used for purposes such as fan cooling, the alternator, and front and rear wipers.
Luxury cars have almost 100 motors, including sensors for HVAC blowers, electronic steering and throttle control, automatic transmissions, and new double-clutch systems. Other uses include seat positioning, sunroofs, tachometers, headlight positioning, headrests, and even control of air input flaps based on air quality information.
Magnetic sensors are used, too, in shaft position encoding—found, for example, in power windows for cars, in which the sensors determine how many complete turns a shaft has made to control the length of travel of the window lifter. The sensor also can detect unusual loading conditions when a hand is present to provide a so-called anti-pinch functionality, which results in the motor turning backward if an obstruction is encountered.
In hybrid electric vehicles, magnetic sensors come into play in the monitoring of auxiliary motor inverters, where the battery direct current needs to be changed to the motor alternating current. Such a conversion requires the use of three current sensors—one for each phase of the motor.
IHS iSuppli points out that both Hall IC and anisotropic magnetoresistive (AMR) sensors are needed for advanced auto applications. In particular, the use of AMR sensors is expected to increase in the next five years for applications like tachometer motors that indicate speed and RPM.