A3230: Chopper-Stabilized Hall-Effect Bipolar Switch


These parts are discontinued.  Samples are no longer available. For new customers or new applications, please refer to Allegro A1250.  Date of status change: December 2, 2013.

The A3230 Hall-effect sensor IC is a temperature stable, stress-resistant bipolar switch. This device is the most sensitive Hall-effect device in the Allegro bipolar switch family and is intended for ring-magnet sensing. Superior high-temperature performance is made possible through an Allegro patented dynamic offset cancellation that utilizes chopper-stabilization. This method reduces the offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress.

The A3230 includes the following on a single silicon chip: a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a short circuit protected open-drain output. Advanced BiCMOS wafer fabrication processing takes advantage of low-voltage requirements, component matching, very low input-offset errors, and small component geometries.

The A3230 Hall-effect bipolar switch turns on in a south polarity magnetic field of sufficient strength and switches off in a north polarity magnetic field of sufficient strength. Because the output state is not defined if the magnetic field is diminished or removed, to ensure that the device switches, Allegro recommends using magnets of both polarities and of sufficient strength in the application.

Top Features

  • Chopper stabilization
    • Superior temperature stability
    • Extremely low switchpoint drift
    • Insensitive to physical stress
  • Reverse battery protection
  • Output short circuit protection
  • Solid state reliability
  • Small size
  • Robust EMC capability
  • High ESD ratings (HBM)

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A3230LUA-T 3-lead SIP -40°C to 150°C Yes View Data Discontinued 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.


The A3230 is rated for operation between the ambient temperatures –40°C and 85°C for the E temperature range, and –40°C to 150°C for the L temperature range. Two A3230 package styles provide magnetically optimized solutions for most applications. Package LH is a SOT23-W, a miniature low-profile surface-mount package, while package UA is a three-lead ultramini SIP for through-hole mounting.

 UA/LH Combination