Diodes Incorporated AH3281Q-P-A

Overview

AH3281Q-P-A from Diodes Incorporated is an AEC-Q100 qualified, two-wire automotive Hall-effect latch switch IC in SIP-3 package, designed for position sensing in seatbelt buckles and gear position detection. 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 (190°C trip), and delivers 6 mA off-state supply current (IOFF(1)).

For engineers reviewing the AH3281Q-P-A datasheet, AH3281Q-P-A pinout, AH3281Q-P-A application, or AH3281Q-P-A equivalent, this device supports high-reliability magnetic sensing in constrained 2-wire automotive wiring harnesses where reverse polarity protection, ISO 26262 readiness, and wide-temperature operation (−40°C to +150°C) are mandatory.

Technical Context

The AH3281Q-P-A implements a chopper-stabilized Hall sensor with dynamic offset cancellation and internal bandgap-regulated supply, 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 environments like door closure or transmission actuation.

It integrates UVLO (2.2 V threshold), overtemperature shutdown with auto-restart, reverse supply protection (−32 V), and ESD resilience (8 kV HBM). The NC pin (Pin 2) is electrically isolated and may be tied to VDD, GND, or left floating without functional impact.

Key Specifications

Pinout & Package

Package: SIP-3 (Ammo Pack), 3-pin single-inline package with straight leads, 14.5 mm body length, 3.0 mm width, and 1.5 mm height. Thermal resistance RθJA = 143 °C/W on 50 mm × 50 mm 2 oz PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL3281Q-P-A and TLE4961-2M, AH3281Q-P-A uniquely combines 2-wire simplicity, built-in diagnostics, and AEC-Q100 Grade 0 qualification-making it optimal for new automotive interior sensing designs where wiring weight, safety compliance, and supply constraints are critical.

Availability

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

Supply support for AH3281Q-P-A 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 solutions for automotive, industrial, and consumer markets.

AH3281Q-P-A belongs to the AH32xxQ automotive Hall switch family, engineered specifically for robust, low-power, two-wire magnetic position sensing in harsh automotive environments.

FAQ

What is the function of Pin 2 (NC) on AH3281Q-P-A?

Pin 2 is a no-connect terminal with no internal bonding or circuit connection. It may be tied to VDD, GND, or left floating without affecting device operation, thermal performance, or magnetic sensitivity. This flexibility simplifies PCB layout and avoids unintended shorts in SIP-3 mounting.

Does AH3281Q-P-A support both high-side and low-side sensing configurations?

Yes-AH3281Q-P-A operates in either high-side or low-side 2-wire sensing topologies. In high-side configuration, the load (RL) connects between V+ and VDD; in low-side, RL connects between VDD and GND. Both require a 100 Ω series resistor and 0.1 µF decoupling capacitor at VDD.

How does the self-diagnostic feature report faults?

On internal fault detection (e.g., UVLO, thermal shutdown, regulator failure), AH3281Q-P-A enters safe mode and draws a reduced, tightly specified supply current of 0.5–1.5 mA (ISAFE). This current shift is detectable by the host controller without additional sensors or pins.

Is AH3281Q-P-A recommended for new designs?

No-per Diodes Incorporated's datasheet (DS41822 Rev. 6-3, page 2), AH3281Q-P-A is marked "NOT RECOMMENDED FOR NEW DESIGNS." Customers developing new platforms should contact Diodes Incorporated for qualified replacements such as the AL3281Q series or next-generation AHx2xxQ variants.