Allegro MicroSystems Europe – High-performance unipolar switch goes

New unipolar Hall-effect switches which offer improved performance compared

with earlier devices and a wider variety of packaging options, including a

version with lead (Pb) free plating, have been introduced by Allegro

MicroSystems Europe.

The A110x family, produced with BiCMOS technology, is intended to replace

the company´s legacy A314x and A312x families of unipolar Hall-effect

switches, and includes five devices (A1101/02/03/04/06) with fast power-on

time and low noise operation.

Device programming is performed after packaging to ensure increased

switch-point accuracy by eliminating offsets that can be induced by package

stress. Novel Hall-element geometries and low-offset amplifiers help to

minimise noise and reduce the residual offset voltage normally caused by

device overmoulding, temperature excursions and thermal stress.

Each device in the family incorporates, on a single silicon chip, a voltage

regulator, Hall-voltage generator, small-signal amplifier, Schmitt trigger,

and NMOS output transistor. The integrated voltage regulator permits

operation from 3.8V to 24V.

Extensive on-board protection circuitry makes possible a ±30V absolute

maximum voltage rating, which provides superior protection in automotive and

industrial motor commutation applications without the need to add any

external components. All devices in the family are identical except for

magnetic switch points.

New packaging options offer a wider choice of design configurations, while

an extended temperature range version is available for automotive and

industrial applications. The A110x family of devices are available in a

3-pin single in-line package (UA) or a three-pin surface-mount package (LH).