The A1233 from Allegro
MicroSystems Europe is a dual-channel, Hall-effect direction detection
sensor IC that provides digital output signals indicating the speed and
direction of a rotating target.
The A1233 is a highly sensitive, temperature-stable
magnetic sensing device ideal for use in ring-magnet based speed and
direction systems in harsh automotive and industrial environments. A key feature of the device is
the fact that the Hall sensing elements are photolithographically
aligned to better than 1 µm. This accurate mechanical location between
the two active Hall elements eliminates the major manufacturing hurdle
commonly encountered in fine-pitch detection applications.The A1233 is a monolithic device containing two independent Hall-effect bipolar
switches located 1.63 mm apart. It provides excellent speed and
direction information for small-geometry targets. Extremely low-drift
amplifiers guarantee symmetry between the switches to maintain signal
quadrature. A patented high-frequency chopper-stabilisation technique
cancels offsets in each channel and provides stable operation over the
full specified temperature and voltage ranges. The high-frequency
chopping circuits also allow an increased analogue signal-to-noise ratio
at the input of the digital comparators in the IC for very low digital
An on-chip low dropout (LDO) regulator allows the A1233 to be used
over a wide operating voltage range. Post-assembly factory programming
at Allegro provides sensitive switch-points that are symmetrical between
the two switches. The A1233 comes in a plastic 8-pin SOIC surface mount
package (L) and a plastic 4-pin single-inline package (K). Both
versions are available for a temperature range from -40°C to +150°C.
Each package is lead (Pb) free, with 100% matt tin-plated leadframe.
Visit Allegro MicroSystems Europe at www.allegromicro.com
This article originally appeared on EE Times Europe.