NXP rolls analog AMR angle sensor for brushless DC motor control

December 12, 2011 // By Christoph Hammerschmidt
NXP Semiconductors has announced the industry's first magnetoresistive angle sensor with integrated amplifier IC. The KMZ60 uses AMR technology (AMR: anisotropic magnetoresistive) and is designed as a low cost, high-performance control device for brushless DC motor (BLDC) commutation. NXP expects that this new sensor will drive uptake of BLDC motor-based applications, particularly in the automotive sector.

Examples of high-precision automotive applications for the KMZ60 are electronic power steering (EPS) or window wiper systems. Other use cases are BLDC motors in industrial applications.

IMS Research forecasts that Brushless DC motors will gain significant market share in automotive applications. Their rising popularity is due to the fact that they offer significant advantages such as greater fuel efficiency, higher accuracy, improved signal-to-noise ratio, and longer lifetime compared to traditional brushed motors. “It is projected that 600 million BLDC motors will be used in traditional light vehicles by 2018 (excluding EVs/HEVs/PHEVs), three times as many as 2011's estimated 200 million units and an 8% gain in market share,” stated IMS Research.

Up to now, cost and complexity of the electronics design had held back the penetration of BLDC motors in vehicles. However, designing with NXP's KMZ60 enables a significant system cost reduction while delivering high speed and accuracy.

The fast response times, robust performance and high accuracy of the KMZ60 makes it ideal for environments where speed and precision are needed. As a pure analog angle sensor, the KMZ60 increases the overall speed of operation, which is vital for safety-critical applications such as steering angle measurement and window wiper application.

Drue Freeman, vice president global automotive sales and marketing, NXP Semiconductors, said: “Modern vehicles have between 10 and 100 electric motors. By replacing traditional motors with brushless DC motors, car manufacturers can realize significant energy savings. The KMZ60 sensor is designed to save system costs and further boost the uptake of energy-efficient equipment. By using a true angular measurement, our magnetoresistive sensors operate reliably independent of magnet shifts and drifts due to lifetime, thermal influences or mechanical stress. This enables high-accuracy readouts even in the most demanding environments - such as the inside of a motor.”

The KMZ60 sensor consists of two microchips within a single SO8 package, an angle sensor and an amplifier integrated circuit (IC) designed to deliver