2-wire Hall-effect switches incorporate diagnostics

July 10, 2017 //By Graham Prophet
Allegro MicroSystems Europe has a family of two-wire vertical Hall-effect switch ICs with advanced diagnostics. Allegro’s A1130, A1131 and A1132 have been developed in accordance with ISO 26262. These devices have integrated continuous diagnostic features and a safe output state that supports a functional safety level of ASIL-B.

These devices feature a two-wire current output interface that facilitates open/short diagnosis along with signal path verification from input to output. These sensor ICs are ideal for safety-critical automotive applications, and can assist a system in meeting the most stringent safety requirements.

 

This family of devices are suited for systems requiring high levels of functional safety such as active and passive occupant restraint systems; electronic power steering systems; advanced driver assistance systems; electronic braking; transmission and clutch systems. The high level of integrated diagnostic capability can help to simplify the safety systems design resulting in lower parts count and lower overall assembly costs.

 

The unipolar Hall-effect switch is sensitive to magnetic fields that are parallel to the surface of the package. These south-pole-sensitive switches are temperature stable and include automotive-grade rugged features such as reverse-battery protection, overvoltage protection, and load dump capability. Each device includes on a single silicon chip: a voltage regulator, diagnostic circuitry, a Hall-voltage generator, a small-signal amplifier, chopper stabilisation, a Schmitt trigger, and an NMOS current output. The on-board regulator permits operation with supply voltages down to 3V.

 

Allegro MicroSystems; www.allegromicro.com