A1202 and A1203: Continuous-Time Bipolar Switch Family

The Allegro A1202 and A1203 Hall-effect bipolar switches are next-generation replacements and extension of the popular Allegro 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 packaging, to ensure increased switchpoint accuracy by eliminating offsets that can be induced by package stress. Unique Hall element geometries and low-offset amplifiers 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 automotive and motor commutation applications, without adding external components. All devices in the family are identical, except for magnetic switchpoints.