Diodes Incorporated AH3281Q-W-7

Overview

AH3281Q-W-7 from Diodes Incorporated is an AEC-Q100 qualified, two-wire automotive Hall-effect latch switch IC in SC59 (Type A1) package, designed for position and proximity sensing in harsh environments. It operates from 2.7V to 27V, features BOP = 8–28 G and BRP = –28 to –8 G at +25°C, includes integrated self-diagnostics, thermal shutdown with auto-restart, and supports seatbelt buckle and gear position detection.

For engineers reviewing the AH3281Q-W-7 datasheet, AH3281Q-W-7 pinout, AH3281Q-W-7 application, or AH3281Q-W-7 equivalent, key selection criteria include latch-type magnetic response, 6 mA off-state supply current (IOFF(1)), ±3.3 µs output jitter, -40°C to +150°C operating range, and ISO 26262 readiness for functional safety integration.

Technical Context

The AH3281Q-W-7 implements a chopper-stabilized Hall sensor architecture with dynamic offset cancellation, delivering stable switching thresholds across temperature. Its latch behavior requires magnetic polarity reversal (south-to-north transition) to release output-ensuring robust state retention in vibration-prone automotive systems.

Internal bandgap regulation supplies temperature-compensated bias to analog blocks, while built-in reverse-blocking diode and zener clamp protect against supply transients up to ±32 V. UVLO activates below 2.2 V, and thermal protection triggers at 190°C junction temperature with release at 180°C.

Key Specifications

Pinout & Package

SC59 (Type A1) surface-mount package with 3-pin single-ended configuration: compact 2.9 mm × 2.8 mm footprint, 1.15 mm height, and 268 °C/W thermal resistance on standard PCB layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Hall latch switch applications.

Compared with AL3281Q-P-A, AH3281Q-W-7 offers smaller SC59 footprint and higher thermal resistance but identical magnetic performance; versus TLE4961-2M, it delivers true two-wire simplicity, wider supply range, and built-in diagnostics - critical for new ASIL-B designs.

Availability

AH3281Q-W-7 is available at Aetrix Electronics and suitable for seatbelt buckle detection, transmission gear position sensing, and door/trunk closure monitoring requiring stable component supply across automotive production lifecycles.

Supply support for AH3281Q-W-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal devices for automotive, industrial, and consumer markets.

AH3281Q-W-7 belongs to the AH32xxQ automotive Hall switch family, engineered specifically for AEC-Q100-compliant position and proximity sensing with integrated diagnostics and functional safety readiness.

FAQ

What is the magnetic polarity requirement for AH3281Q-W-7 activation?

AH3281Q-W-7 is a south-pole-activated latch switch: output turns ON when south pole flux exceeds BOP (8–28 G), and remains ON until north pole flux falls below BRP (−28 to −8 G). This polarity-specific latch behavior ensures reliable state retention without continuous magnetic presence.

Does AH3281Q-W-7 require an external bypass capacitor?

Yes - a minimum 100 nF ceramic decoupling capacitor must be placed between VDD and GND, as close as possible to the IC pins. This stabilizes internal regulation, suppresses supply noise, and ensures robust operation under load dump or cranking transients per automotive EMC requirements.

How does the self-diagnostic function operate in AH3281Q-W-7?

The self-diagnostic feature monitors internal voltage references, oscillator stability, and Hall element integrity. Upon detecting fault conditions (e.g., open Hall path, regulator failure), it forces ISAFE current (0.5–1.5 mA) instead of normal IOFF/ION, signaling error to the host controller without requiring additional sense resistors or external logic.

Can AH3281Q-W-7 be used in high-humidity or under-hood environments?

Yes - AH3281Q-W-7 is qualified to AEC-Q100 Grade 0 (−40°C to +150°C), packaged in moisture-resistant SC59 (Type A1), and features integrated reverse-voltage and transient protection. Its lead-free, halogen-free construction meets automotive environmental compliance standards including RoHS 3 and IATF 16949 manufacturing controls.