Programmable Hall Switch

The HAL® 1000 is a programmable Hall switch. The major sensor characteristics, the two switching points Bon and Boff, are programmable for the application. The sensor can be programmed to be unipolar or latching, sensitive to the magnetic north pole or sensitive to the south pole, with normal or with an electrically inverted output signal. The HAL 1000 is based on the HAL 8xx family and features a temperature-compensated Hall plate with choppered offset compensation, an A/D converter, digital signal processing, a push-pull output stage, an EEPROM memory with redundancy and lock function for the calibration data, a serial interface for programming the EEPROM, and protection devices at all pins. Internal digital signal processing is of great benefit because analog offsets, temperature shifts, and mechanical stress effects do not degrade the sensor accuracy. The HAL 1000 is programmable by modulating the supply voltage. No additional programming pin is needed. Programming is simplified through the use of a 2-point calibration. Calibration is accomplished by adjusting the sensor output directly to the input signal. Individual adjustment of each sensor during the customer’s manufacturing rocess is possible. With this calibration procedure, the tolerances of the sensor, the magnet, and the mechanical positioning can be compensated for the final assembly. This offers a low-cost alternative for all applications that presently require mechanical adjustment or other system calibration. In addition, the temperature compensation of the Hall IC can be tailored to all common magnetic materials by programming first and second order temperature coefficients of the Hall sensor sensitivity. This enables operation over the full temperature range with constant switching points. The calculation of the individual sensor characteristics and the programming of the EEPROM memory can easily be done with a PC and the application kit from Micronas. The sensor is designed and produced in sub-micron CMOS technology for use in hostile industrial and automotive applications with nominal supply voltage of 5 V in the ambient temperature range from - 40 °C up to 150 °C. The HAL 1000 is available in the leaded packages TO92UT-1 and TO92UT-2.