Dual-Hall sensor detects rotation direction & speed

The TLE4966 switch family is designed to detect the rotation direction and rotation speed of a magnetic pole wheel. The vertically integrated Hall plates in TLE4966V enable sensing of in-plane, instead of perpendicular, magnetic fields. Changing sensing orientation by 90 degrees allows system engineers to design new and previously unattainable mechanical concepts. This is especially valuable for space-restricted applications such as power window lifts and electronic trunk lifts.

Detecting the direction and speed of rotation of a magnetic pole wheel requires two separate Hall plates. Due to the distance between the two plates, they detect slightly different signals at any designated time. This is termed the phase difference. During a rotation direction change, the phase difference changes polarity. The vertical dual-Hall sensor detects this change and delivers a corresponding signal. The rotation speed of a magnetic pole wheel can directly be calculated with the second sensor output signal. This signal is triggered by each polarity change of the magnetic field.

The two integrated vertical Hall plates on one silicon die within the sensor have the same behavior for temperature and lifetime stress, with no sensitivity deviation over lifetime. Furthermore, the sensor has two signal outputs: one signal for the magnet rotation direction, the other signal for the pole wheel rotation speed. That means that a single device delivers all relevant information where previously two sensors have been required. Eliminating a second, separately packaged sensor can simplify the PCB design, reduce sensor cost by an average of 30% and lower test and manufacturing time by up to 50%.

The vertical dual-Hall sensor performs on-chip signal processing, which offers three main advantages for the system designer: rapid sensor signal availability for fast applications, no microcontroller programming and no programming mistakes resulting in higher system quality. The TLE4966V sensor allows operation from an unregulated power supply, compatible with systems from 3.5V to 32V. It comes in a Thin Small Outline Package with 6 pins (TSOP-6).

The design flexibility and the 4mA to 7mA current consumption of the sensor make it well-suited for energy-sensitive electronic automotive systems such as trunk lifts, power window lifts, sun roofs and seat adjustment. In non-automotive applications, the sensor is also an excellent solution for escalators, motorized window blinds and shades.

“With the new TLE4966V we expand our leadership in dual-Hall sensors,” says Ralf Bornefeld, Vice President and General Manager of the Sense and Control business at Infineon Technologies. “The sensor is a perfect extension of our TLE4966 family which set the industry standard in window lifter and other index counting applications. The implementation of vertical Hall plates enables our customer to realize new system designs and underlines our ability to think from product to system.”

Availability

TLE4966V samples are available now with production start planned for July 2014.