A1201

The Allegro® A1201, A1202, A1203 and A1204 Hall-effect bipolar switches are  next-generation replacements and extension of the popular Allegro A3134, A3133,  and A3132 bipolar switch product line. Overall, the A120x family, produced with  BiCMOS technology, consists of continuous-time devices that feature fast power- on time and low-noise operation. Device programming is performed after packag- ing, to ensure increased switchpoint accuracy by eliminating offsets that can be  induced by package stress. Unique Hall element geometries and low-offset ampli- fiers help to minimize noise and to reduce the residual offset voltage normally  caused by device overmolding, temperature excursions, and thermal stress.

The A120x Hall-effect bipolar switches include the following on a single silicon  chip: voltage regulator, Hall-voltage generator, small-signal amplifier, Schmitt  trigger, and NMOS output transistor. The integrated voltage regulator permits  operation from 3.8 to 24 V. The extensive on-board protection circuitry makes  possible a ±30 V absolute maximum voltage rating for superior protection in auto- motive and motor commutation applications, without adding external components.