The APS11450 is a family of unipolar switch integrated circuits, while the APS12450 devices are bipolar latches. They are pin-compatible upgrades for existing Hall switch integrated circuits and three-wire latches developed in accordance with ISO 26262:2011 with ASIL-B capability (assessment pending).
These magnetic sensors have built-in self-test functions that are always active in the background while the system is running, resulting in very short fault detection times. This action is automatic, and the tests run so quickly (25 µs, typical) that they are transparent to the host system, even in the case of latches used in high-speed motors and encoders. The unique voltage-mode output communicates the sensor's status (including the safe state) while remaining compatible with logic-level interfaces, application circuitry, wiring, and firmware.
"Our challenge was to achieve the level of security required by current and future ADAS systems, while remaining compatible with our installed base of billions of Hall switches and latches," explains Jim Judkins, Product Line Manager for Digital Position Sensor ICs at Allegro. "The result is the fastest diagnostics available for magnetic switches and latches, and a compatible logic output that can communicate sensor status and support open/short wiring detection.".
With their versatile applications, the APS11450 and APS12450 were designed to enhance the performance of a variety of automotive and intelligent motion system applications. They are ideal for use in advanced driver assistance systems (ADAS) and encoders for power windows, power seat motors, seat belt tensioners, and locking systems. These integrated circuits are also suitable for off-road vehicles, heavy equipment, human-machine interfaces (HMIs), roll (bank angle) sensors, kickstands, and driver controls on two-wheeled vehicles.
The APS11450/12450 sensors are rated above AEC-Q100 Grade 0 requirements. They were developed according to ISO 26262 as an out-of-context hardware safety element with ASIL-B capability (assessment pending), making them suitable for automotive safety systems. The integrated safety features are also beneficial for other safety systems. Using the APS11450/12450 devices, an ASIL-B (or higher) rating can be achieved without redundant sensors, resulting in smaller, lower-power, and lower-cost systems.
The devices are offered in two packages, with magnetic characteristics that match traditional Hall effect sensors, making them highly flexible and easy to design. These monolithic integrated circuits can operate from 3.3 to 24 V and at a junction temperature of up to 175°C, surviving up to +35 V inputs, reverse battery voltage (-30 V), output short circuits, load drops, and other overvoltage transients. The Allegro LH miniature package is an SOT-23W style package for surface-mount applications; the UA is a 3-pin SIP (Single Inline Package) for through-hole mounting. Both packages are lead-free (Pb) with a 100% matte tin-lead coating.
