Rugged micropower magnetic sensor ICs maximise battery life

The power management happens in the background and is transparent to the host system, making them a drop-in upgrade for existing Hall-effect switches or a solid-state replacement for mechanical microswitches or reed switches. 

"Thanks to the APS11700/760’s combination of ruggedness and ultra-low power, there is finally a reliable, solid-state upgrade for reed and microswitches, even in the most power-sensitive applications where the sensor will be connected directly to the battery," explained Jim Judkins, Product Line Director for Allegro's Position Sensor ICs.

These monolithic devices include either a standard Hall plate or a vertical Hall plate, a small-signal amplifier, chopper stabilisation, a Schmitt trigger, automatic power management controller, and an NMOS output transistor. The APS11700 uses a standard planar Hall-effect sensing element, while the APS11760 implements AVHT technology in the form of a silicon-based vertical Hall-effect sensing element. The APS11760 devices are therefore sensitive to magnetic flux parallel to the face of the IC package, mimicking the in-plane sensitivity of common reed switches. 

The APS11700/760 devices come preconfigured with the user’s choice of magnetic sensitivity, thresholds, and polarity; there is also a choice of active-high or active-low output for ease of integration into electronic subsystems. These ICs are qualified to AEC-Q100 Grade 0 and compliant with ISO 26262:2011 ASIL A when properly applied, making them suitable for automotive and other safety systems. They can tolerate up to 40V and junction temperature up to 165°C.  In addition, they are internally protected against overvoltage, reverse-battery, load-dump, output short-circuits, human-body-model ESD up to ±11kV, and other EMC conditions.

Typical applications include:

• Open/close/latch sensors for automotive doors, lids, trunks, LCD screens, interior lighting, etc.
• Shifters, pedals, and other driver controls / Human-Machine Interfaces (HMI)
• Fluid level sensing
• Tip-over (bank angle), kickstand, and HMI sensors in 2- and 3-wheeled vehicles
• White goods / Appliances
• Intelligent motion, e.g., robotics, vending machines, exercise equipment, motorised blinds/shades/shutters, etc.

Two package styles are available; Allegro’s LH package is a SOT-23W style, miniature, low-profile package for surface-mount applications; the UA is a 3-pin, ultra-mini, single inline package (SIP) for through-hole mounting. Both packages are lead (Pb) free, with 100% matt-tin leadframe plating.