This document describes the A1185 and A1186, two ultrasensitive two-wire unipolar Hall effect switches. These switches have an operable point that can be field-programmed after final packaging and placement in the application, allowing for optimized sensor switching performance.
The A1185 and A1186 are ultrasensitive, two‑wire, unipolar Hall‑effect switches with field‑programmable operate points. They are built using Allegro's DABICS BiCMOS process and feature chopper‑stabilization to minimize offset and temperature drift. These devices are used in automotive applications such as seat‑track position, seat‑belt buckle detection, and hood/trunk latching.
Both parts are offered in two package styles: LH (SOT‑23W surface‑mount) and UA (three‑lead SIP through‑hole). They include on‑chip transient protection, a Zener clamp on the supply line, and optional factory‑programmed versions. Detailed electrical, magnetic, and thermal characteristics are provided for design integration.
| Supply Voltage (VCC) | 3.5 V – 24 V |
|---|---|
| Chopping Frequency | 200 kHz |
The devices operate from 3.5 V to 24 V supply voltage.