Hall effect switch does away with mechanical adjustments

May 21, 2014 // By Christoph Hammerschmidt
The MLX92242 from Melexis is a highly integrated Hall effect switch/latch IC designed for automotive applications, such as seatbelt latch detectors, seat position sensors or window lifters. Its non-volatile memory enables car manufacturers to carry out end-of-line (EOL) programming, allowing cancellation of all mechanical tolerances within the application.

Programmable memory is used to enable the various tolerances that need defining for a specific application to be set and if necessary readjusted, before finally being locked. The range and resolution of programmable magnetic thresholds and thermal sensitivity coefficients allows the sensor working in conjunction with a magnet to easily implement a ferrous metal proximity sensing system. Since its temperature compensation characteristics can be programmed, the MLX92242 can be used with all kind of magnets - including low cost ferrite materials. The resulting cost-effective and very small ferrous proximity switch handily serves many limit position, proximity detection and encoding applications.

Another differentiator of the MLX92242 is that it supports 2-wire rather than a 3-wire implementation, only needing use of the VDD and GND pins, but still providing all the necessary diagnostic capacity to respond if malfunction conditions occur. The advantage of this is that less wiring/cable harnessing is needed, allowing deployment into confined spaces and reducing the overall weight in applications where this could otherwise be a disadvantage.

The MLX92242 can be implemented in remote applications, where it is some distance from the electronic control unit (ECU). The proprietary offset cancellation system within the magnetic core enables faster and more precise processing of the data acquired from the sensing element while being resilient to the temperature fluctuations and other forms of stress that are inherent in automotive and industrial environments. The device has a very high resilience to electro-static discharge (ESD) phenomena, with 8kV human body mode ESD compliance, and has a broad operational temperature range which spans from -40°C to 150°C.

For more information visit www.melexis.com