Micronas today announced its first linear Hall-effect sensor family, HAR 24xy, integrating two fully automotive-qualified dies in a thinner than 1-mm TSSOP14 package for high-precision redundant measurements and smaller magnet designs. The first members, HAR 2425 and HAR 2455, are designed to meet the performance, diagnostic, and safety requirements of most demanding automotive and industrial applications and will be presented to the public from February 24 to 26, 2015, at Embedded World in Nuremberg, Germany. First samples are available in May 2015. Start of production is planned for the second half of the year.
The new sensor family particularly suits automotive applications, such as throttle position measurement, pedal position detection, and exhaust gas recirculation (EGR), but can be used also for current measurement and every kind of position detection or as an alternative to contactless potentiometers. For these applications, the very thin TSSOP14 package brings several benefits. It fits into space-demanding applications with reduced air gap. The very small distance between the Hall plates of the dies improves the correlation between the two output signals. The resulting improved sensitivity of the sensor enables a much smaller magnet design. Furthermore, the magnet is located closer to the sensor’s active area, which makes the overall design less sensitive to stray parasitic fields.
“This integration of two dies brings true system redundancy at the supply and output levels while offering the best features of our proven HAL 24xy linear Hall-sensor family—for example its high immunity against temperature variations or its design flexibility”, said Dirk Behrens, vice president, automotive, at Micronas.
The sensor’s high accuracy is based on a 16-bit signal path with an integrated digital signal core delivering a ratiometric 12-bit analog (HAR 2425) or up to 2-kHz PWM (HAR 2455) output signal. Both versions include an output linearization compensation function using 16 programmable set points to correct magnet linearity errors or to increase distance measurements. Enhanced detection functions and error diagnostic coverage offer numerous capabilities including wire break detection and thermal supervision in the case of overcurrent or short-circuit events. When an over-temperature between two sensor outputs is detected, different modes can be defined as to how the device reports the failure—with output set to ground, supply, or tristate configuration. Furthermore, during normal operation the whole sensor signal path and the memory map are supervised by a continuous self-test of various circuit blocks.
To ease design and production activities there is a development board available together with NI LabVIEW-based programming software.
