Hall effect ICs offer a wide choice of switching sensitivities for proximity detection

Diodes Incorporated has added two enhanced high-voltage, Hall effect switch IC families to its automotive-compliant product portfolio. The AH332xQ (unipolar) and AH352xQ (omnipolar) provide a wide range of operating sensitivity options in SIP-3, SOT23 (Type S), and SC59 packages. The devices can be employed in various contactless position and proximity detection applications, including seatbelt fastening, door and trunk latching, windshield wipers, and steering-wheel locks.

The unipolar AH332xQ is activated when the magnetic flux density of correct polarity exceeds the defined operating threshold (BOP) and switches off when the flux density falls below the release threshold (BRP). Ten sensitivity options are offered, ranging from a highly sensitive 30G BOP to a low-sensitivity 275G BOP version, permitting a wide range of magnet and distance options for optimal sensing.

The omnipolar AH352xQ is activated when the magnetic flux density of either magnetic south or north pole exceeds the BOP and turns off when the magnetic flux density falls under the BRP. Three high-sensitivity options range from ±20G to ±40G BOP devices.

The BOP and BRP thresholds for the AH332xQ and AH352xQ provide a tight operating window with sufficient hysteresis for reliable operation, while a low-temperature coefficient ensures the stability of the switching points.

The Hall effect devices have an open-drain output and operate over a wide 3V to 28V supply voltage range and -40C to +150C temperature range, delivering product design flexibility to fulfil the demands of the harsh automotive environment. The devices maintain accurate sensitivity levels even when physical stress is applied to the package. For enhanced robustness and reliability, the devices have reverse blocking diodes with Zener clamps on their supply pins and overcurrent limits and Zener clamps on their open-drain output. ESD protection exceeds 8kV HBM and 1kV CDM, and the devices have a 40V load-dump capability.