Hall Switch & Latch ICs Integrate Self-Test For ADAS Safety

Allegro MicroSystems’ APS11450 and APS12450 expand the company’s portfolio of solutions for systems that require functional safety. The APS11450 is a family of unipolar switch ICs, while the APS12450 devices are bipolar latches. They are pin-compatible upgrades for existing three-wire Hall switch and latch ICs developed in accordance with ISO 26262:2011 with ASIL-B capability (pending assessment).

 

The magnetic sensors have integrated self-test features that are always active in the background while the system is running, leading to very short fault detection times. This action is automatic, and the tests are executed at a typical speed of 25 µs. The unique voltage-mode output communicates the sensor’s status, including the safe state, while remaining backward compatible with logic-level interfaces, application circuits, wiring, and firmware.

 

Both devices were designed to enhance the performance of a variety of automotive applications and intelligent motion systems. They are suitable for use in advanced driver assistance systems (ADAS) and encoders for window lifts, seat motors, seatbelt tensioners, and closure systems. They are also suited for off-road vehicles, heavy equipment, human machine interfaces (HMI) and roll-over (bank angle) sensors, kickstands and driver controls in two-wheeled vehicles.

 

The APS11450/12450 are qualified beyond the requirements of AEC-Q100 grade 0. They were developed to ISO 26262 as a hardware safety element out of context with ASIL-B capability (pending assessment), making them suitable for automotive safety systems.

 

The devices are offered in two packages with magnetic characteristics that match legacy Hall sensors. They can operate from 3.3V to 24V and up to 175°C junction temperature, surviving up to +35V inputs, reverse-battery down to -30V, output shorts, load-dump, and other over-voltage transients.  Allegro’s miniature LH package is a SOT-23W style package for surface-mount applications; the UA is a 3-pin, single inline package (SIP) for through-hole mounting. Both packages are lead (Pb) free, with 100% matte-tin leadframe plating. For more details, get your copy of the APS11450 and APS12450 datasheets today.