A1233: Dual-Channel Hall-Effect Direction Detection Sensor IC


The A1233 is a dual-channel Hall-effect sensor IC ideal for use in speed and direction sensing applications incorporating encoder ring-magnet targets. The A1233 provides various output signals that indicate speed and direction of target rotation. The Hall elements are both photolithographically aligned to better than 1 μm. Maintaining accurate displacement between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A1233 is a highly sensitive, temperature-stable magnetic device ideal for use in harsh automotive and industrial environments.

The Hall elements of the A1233 are spaced 1.63 mm apart, which provides excellent speed and direction information for small-geometry targets. Extremely low-drift amplifiers guarantee symmetry between the switches to maintain signal quadrature. An on-chip regulator allows the use of this device over a wide operating voltage range of 3.5 to 24 V.

End-of-line trimming of the Hall element switchpoints provides tight matching capability. The Allegro® patented, highfrequency chopper-stabilization technique cancels offsets in each channel, providing stable operation over the full specified temperature and voltage ranges.

The A1233 has integrated protection against transients on the supply and output pins and short-circuit protection on all outputs.

The A1233 is available in a 4-pin SIP and a plastic 8-pin SOIC surface mount package. Both packages are lead (Pb) free, with 100% matte tin leadframe plating.

Top Features

  • AEC-Q100 automotive qualified 
  • Precisely aligned dual Hall elements
  • Tightly matched magnetic switchpoints
  • Speed and direction outputs
  • Individual Hall element outputs (L package)
  • Output short-circuit protection
  • Operation from an unregulated power supply
  • Wide operating temperature range
  • Wide operating voltage range
  • Integrated EMC-ESD protection
  • Superior temperature stability and industry-leading jitter performance through use of advanced chopper stabilization topology

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A1233LK-T 4-lead SIP -40°C to 150°C -- View Data Contact your
local sales rep
Distributor Stock
A1233LLTR-T 8-lead SOIC -40°C to 150°C Yes View Data Contact your
local sales rep
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.



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