The A3425 is a dual–output-channel, bipolar switch with
each channel comprising a separate complete Hall-effect
sensor circuit with dedicated Hall element and separate digital
output for speed and direction signal processing capability. The
independent Hall elements (E1 integrated with OUTPUTA, and
E2 integrated with OUTPUTB) are photolithographically aligned
to better than 1 μm. Maintaining this accurate mechanical
location between the two active Hall elements eliminates the
major manufacturing hurdle encountered in fine-pitch detection
applications. The A3425 is a highly sensitive, temperature-stable
magnetic sensing device, which is ideal for use in ring magnetbased
speed and direction systems used in harsh automotive
and industrial environments.
The A3425 contains two independent Hall effect switches, and
has a monolithic IC that accurately locates the two Hall elements,
E1 and E2, approximately 1 mm apart. The digital outputs are
90o out of phase so that the outputs are in quadrature, with the
proper ring magnet design. This allows for easy processing of
speed and direction signals. Extremely low-drift amplifiers
guarantee symmetry between the switches to maintain signal