Micronas Offers Hall-Effect Sensors with PWM and SENT Interfaces

Micronas has announced two members of its varioHAL family of integrated Hall-effect sensors, with digital interfaces enabling robust and reliable data transfer in harsh automotive environments. The HAL 2830 and HAL 2850 include a microcontroller, temperature sensor, advanced on-chip compensation, and digital output format. The HAL 2850 features a pulse-width modulated (PWM) interface, and the HAL 2830 has a SENT interface, used particularly for low-cost automotive sensors in high-noise environments. The HAL 2850 can be programmed to send pulses as slow as 30 per second or as fast as 2000 per second. This wide range allows the system designer to tailor it to the system needs. A slower update rate may suffice for slowly changing variables, such as temperature, and reduces the overall load on the microcontroller.



The HAL 2830 takes this a step further. It uses the SAE J2716 SENT standard to transmit sensor information, again using the time between pulse edges to represent the sensor value. The HAL 2830 also includes a sensor-status signal, as well as the measured value. SENT can replace lower-resolution methods using 10-bit A/D converters and PWM techniques and provides a simpler, low-cost alternative to digital buses, such as CAN or LIN. SENT is used particularly for low-cost automotive sensors in high-noise environments. Both the HAL 2850 and HAL 2830 offer 12-bit accuracy. The devices have open-drain outputs but offer slew-rate control on these to reduce electromagnetic interference problems. In addition, the HAL 2830 offers a temperature measurement capability. The HAL 2830 and HAL 2850 are offered in a TO-92UT package rated for use from –40°C to 170°C. Pricing and availability vary with model.