The A3046EU/LU, A3056EU/LU, and A3058EU/LU Hall effect
gear-tooth sensors are monolithic integrated circuits that switch in
response to differential magnetic fields created by ferrous targets.
These devices are ideal for use in gear-tooth-based speed, position,
and timing applications and operate down to zero rpm over a wide
range of air gaps and temperatures. When combined with a backbiasing
magnet and proper assembly techniques, devices can be
configured to give 50% duty cycle or to switch on either leading,
trailing, or both edges of a passing gear tooth or slot.
The six devices differ only in their magnetic switching values and
operating temperature ranges. The low hysteresis of the A3046/56EU
and A3046/56LU makes them perfectly suited for ABS (anti-lock brake
system) or speed sensing applications where maintaining large air
gaps is important. The A3046EU/LU features improved switch point
stability with temperature over the A3056EU/LU. The high hysteresis
of the A3058EU and A3058LU, with their excellent temperature
stability, makes them especially suited to ignition timing applications
where switch-point accuracy (and latching requirements) is extremely
important.