Date: 24/04/2012

General purpose bipolar switch 'A1250' released by Allegro

Allegro MicroSystems has released a new bipolar switch designed with a high speed chopping circuit to null out offsets and dramatically improve switching repeatability.

Allegro's A1250 is a temperature-stable and stress-resistant Hall-effect, bipolar switch. This device operates over extended temperature ranges to +150°C. This device is targeted at the automotive, industrial and consumer markets.

The design includes on a single silicon chip a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a short-circuit-protected, open-collector output. A south pole of sufficient strength will turn the output on. A north pole is necessary to turn the output off.

An on-board regulator permits operation with supply voltages of 3.0 to 24 V. The advantage of operating at 3.0 V is that it can be used in 3 V applications or additional external resistance can be added in series with the supply pin for greater protection in applications that can supply higher voltages.

The switch is offered in both surface mount and through-hole mount packages. 'LH' package type is a modified SOT-23W package, while the UA type is a three-lead SIP package. Each package type is only available as lead (Pb) free (suffix, -T), with a 100% matte tin plated lead frame.