The A3422xKA Hall-effect, direction-detection sensor is a new
generation of special-function integrated sensors that is capable of sensing
the direction of rotation of a ring magnet. This transducer provides
separate digital outputs that provide in for ma tion on magnet rotation
speed, direction, and magnet pole count. This device elim i nates the major
manufacturing hurdles encountered in fi ne-pitch direction-detection
ap pli ca tions, namely maintaining accurate me chan i cal location between
the two active Hall elements. Here, the two Hall elements are photolithographically
aligned to better than 1 μm, as contrasted with 100 μm
or worse mechanical location tol er ance when manufactured discretely.
This highly sensitive, tem per a ture-stable, magnetic transducer is ideal
for use in digital-encoder systems in the harsh environments of automotive
or industrial ap pli ca tions. The A3422xKA is a high-sensitivity
device op ti mized for use with high-density magnets.
The A3422xKA monolithic integrated circuit contains two in de -
pen dent Hall-effect bipolar switches whose digital outputs are in ter nal ly
cou pled to CMOS logic circuitry that decodes signal speed and di rec -
tion. Ex treme ly low-drift BiCMOS circuitry is used for the amplifi ers
to ensure symmetry between the two switches so that signal quadrature
can be maintained. An on-chip voltage regulator allows the use of this
device from a 4.5 V to 18 V supply. The outputs are stan dard open-collector
outputs.
Two operating temperature ranges are provided; suffi x ‘E–’ is for
the automotive and industrial temperature range of -40°C to +85°C, suffi
x ‘L–’ is for the automotive and military temperature range of
-40°C to +150°C. The 5-pin ‘KA’ SIP package provides a cost-compet
i tive solution to magnetic sensing in harsh en vi ron ments.
FEATURES
? Internal Direction-Decoding Circuitry
? Two Matched Hall Bipolar Switches on a Single Substrate
? Superior Temperature Stability
? 4.5 V to 18 V Operation
Electrically Defi ned Power-On State
Undervoltage Lockout