Product category:
Rotary Position, Tilt and Angular Sensors
News Release from: Allegro MicroSystems Europe | Subject: A3425 dual Hall-effect switch
Edited by the Engineeringtalk Editorial
Team on 22 August 2000
Hall-effect switch IC ideal for
direction sensing
The A3425 dual Hall-effect switch is an ultra-sensitive dual sensor integrated circuit that is ideally suited to fine-pitch direction-sensing applications in harsh automotive environments
The A3425 dual Hall-effect switch from Allegro MicroSystems is an ultra-sensitive dual sensor integrated circuit that is ideally suited to fine-pitch direction-sensing applications in harsh automotive and industrial environments In operation, the A3425 provides digital quadrature outputs for easy signal processing through the use of precision aligned Hall elements and low-drift BiCMOS circuitry
This article was originally published on Engineeringtalk on 19 Feb 2001 at 8.00am (UK)
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The new device is extremely temperature-stable and stress-resistant, offering reliable operation over extended temperature ranges up to +150øC.
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The A3425 includes, on a single silicon chip, a voltage regulator, two independent Hall-voltage generators, two small-signal amplifiers with chopper stabilisation, two Schmitt triggers, and two short-circuit protected open-collector outputs to sink up to 30 mA each.
An on-board voltage regulator permits operation with supply voltages from 3.3 to 26.5 V.
With suitable output pull-ups, it can be used directly with bipolar or MOS logic circuits.
Allegro MicroSystems has eliminated the major manufacturing problems encountered in fine-pitch direction-detection applications: namely, maintaining accurate mechanical location between the two active Hall elements.
In the A3425, the two Hall elements are photolithographically aligned to better than 1 mm, as contrasted with the 100 mm (or more) mechanical location tolerance typical of discrete manufacture.
The high sensitivity of the A3425 makes it ideal for use with high-density magnets.
The spacing of 1 mm between the two elements means that the device will maintain perfect quadrature with a magnet-pole spacing of only 2 mm.
The A3425 dual Hall-effect switch is supplied in a 4-pin plastic single inline package for operation over a temperature range of -40C to +150C.
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