Diodes Incorporated AH1381-HK4-7

Overview

AH1381-HK4-7 from Diodes Incorporated is a high-sensitivity, ultra-low-power digital unipolar Hall-effect switch IC designed for magnetic proximity sensing in battery-constrained systems. It operates with 1.6V–5.5V supply, draws only 1.6μA average current at 3V, and switches on when exposed to ≥18G south-pole magnetic flux perpendicular to the package top surface - enabling reliable lid-open detection in smart meters and smoke detectors.

For engineers reviewing the AH1381-HK4-7 datasheet, AH1381-HK4-7 pinout, AH1381-HK4-7 application, or AH1381-HK4-7 equivalent, key selection criteria include its 1.6μA avg. supply current, 18G/11G magnetic operate/release points (typ.), SOT23/X2-DFN1410-4 package options, chopper-stabilized temperature stability, and integrated output driver eliminating external pull-up resistors.

Technical Context

The AH1381-HK4-7 implements a chopper-stabilized Hall sensor with sleep/awake logic and latch-based output driver, achieving ±7G magnetic hysteresis and <±10% BOP drift over –40°C to +85°C. Its hibernating clocking system cycles between 30–80ms periods, reducing IDD(AVG) to 1.6μA while maintaining 30–80μs wake latency for responsive switching.

It features internal offset cancellation and absolute maximum ratings of 6V VDD (transient), 8kV HBM ESD, and 1mA output sink capability. The device requires no external components beyond a 100nF bypass capacitor (CIN) placed near VDD to ensure noise immunity and power stabilization.

Key Specifications

Pinout & Package

Package: X2-DFN1410-4 (Type B), 1.4mm × 1.0mm × 0.37mm, exposed thermal pad (no internal connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unipolar Hall-effect switch applications.

Compared with AL33130T-20X-7 and DRV5013AGQLPG, AH1381-HK4-7 delivers the lowest power (1.6μA) in the smallest footprint (1.4mm²), making it optimal for long-life, size-sensitive battery applications where unipolar south-pole activation is sufficient.

Availability

AH1381-HK4-7 is available at Aetrix Electronics and suitable for smart metering, smoke detection, and portable electronics requiring stable component supply with guaranteed long-term manufacturability and RoHS/Green compliance.

Supply support for AH1381-HK4-7 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 company specializing in discrete, analog, and mixed-signal ICs, with design centers across Asia, Europe, and the U.S., serving industrial, consumer, and communications markets.

AH1381-HK4-7 belongs to Diodes' Hall-effect switch product line, engineered specifically for ultra-low-power magnetic sensing in battery-operated endpoints - emphasizing energy efficiency, magnetic consistency, and compact packaging for next-generation IoT and smart home devices.

FAQ

What is the magnetic polarity requirement for AH1381-HK4-7 activation?

The AH1381-HK4-7 activates only with the south pole of a magnet oriented toward the marked side of the package. It does not respond to north-pole fields. The typical operate point is 18 Gauss, measured perpendicular to the top surface. This unipolar behavior simplifies magnet placement in lid-detection applications where consistent orientation is guaranteed.

Can AH1381-HK4-7 operate directly from a 1.8V microcontroller I/O rail?

Yes - AH1381-HK4-7 functions down to 1.6V supply voltage, making it compatible with 1.8V logic domains without level-shifting circuitry. Its open-drain output pulls low to ≤0.25V at 1mA load, ensuring clean logic-low recognition by 1.8V MCUs, and remains high-impedance otherwise, eliminating static power draw on the host interface.

Is an external capacitor required for stable operation?

Yes - a 100nF ceramic capacitor (CIN) is mandatory between VDD and GND, placed as close as possible to the device pins. This stabilizes the internal regulator during wake cycles and enhances RF noise immunity. Omitting CIN risks erratic switching or increased IDD(AVG) due to supply ripple-induced false triggers.

Does AH1381-HK4-7 require PCB layout adjustments for thermal performance?

No dedicated thermal pads or copper pours are required - the X2-DFN1410-4 package has a center exposed pad with no internal connection. Thermal dissipation is negligible (max 230mW), and the device operates reliably at ambient temperatures up to +85°C with standard FR-4 PCB layout. Ensure GND pin has solid connection to ground plane for electrical stability.