Diodes Incorporated AH3724-W-7

Overview

AH3724-W-7 from Diodes Incorporated is a high-voltage, bipolar Hall-effect latch IC optimized for brushless DC motor commutation and angular position sensing in automotive and industrial systems. It operates from 3.0V to 28V, features open-drain output with 30–55mA current limiting, BOP/BRP of 20–60G / –60G to –20G (typ), and is housed in SC59 package rated for –40°C to +125°C.

For engineers reviewing the AH3724-W-7 datasheet, AH3724-W-7 pinout, AH3724-W-7 application, or AH3724-W-7 equivalent, key selection criteria include magnetic sensitivity hysteresis (40–120G), chopper-stabilized temperature stability, reverse supply protection (–18V), ESD robustness (8kV HBM), and compatibility with 3.0–28V supply rails in harsh environments.

Technical Context

The AH3724-W-7 implements a chopper-stabilized architecture with dynamic offset cancellation and internal bandgap regulation, delivering minimal switch-point drift (<±0.5G/°C typical) and superior immunity to thermal stress and mechanical package strain. Its bipolar latching behavior-South pole activation (BOP ≥ 20G), North pole deactivation (BRP ≤ –20G)-enables precise zero-crossing detection in rotating systems.

Functional block integration includes low-pass filtering, sample-and-hold amplification, and a power switch with overcurrent limit and zener-clamped output. The device uses an internal reverse-blocking diode and supply-side zener clamp (28V) to withstand transient reverse voltage up to –18V and ensure reliable operation under load dump or battery reversal conditions.

Key Specifications

Pinout & Package

SC59 package: 3-pin, single-row, surface-mount plastic package with gull-wing leads; footprint compatible with SOT-23 but with larger pad pitch (0.95mm lead-to-lead spacing) and higher thermal dissipation (550mW).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL3724QSA-7 and US5781LUA-AAA-000, the AH3724-W-7 offers optimal balance of automotive-grade robustness (reverse protection, 8kV ESD, 125°C rating) and industrial flexibility (no AEC-Q100 overhead, lower unit cost), making it ideal for Tier-2 automotive modules and high-reliability industrial motion control.

Availability

AH3724-W-7 is available at Aetrix Electronics and suitable for brushless DC motor commutation, flow meter RPM measurement, and angular position indexing requiring stable component supply across automotive, industrial automation, and appliance OEM programs.

Supply support for AH3724-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 solutions for power management, signal integrity, and sensing applications.

The AH372X series belongs to Diodes' high-voltage Hall-effect sensor product line, engineered specifically for demanding rotational sensing in automotive powertrain, industrial motor control, and white-goods applications where reliability under voltage transients and temperature extremes is critical.

FAQ

What is the magnetic polarity response of the AH3724-W-7?

The AH3724-W-7 is a bipolar latch: it turns ON (pulls OUTPUT low) when a South pole with flux density ≥20G (typ) is applied to the marked side of the SC59 package, and remains latched until a North pole with flux density ≤–20G (typ) is applied to the same side. This behavior is confirmed in the magnetic characteristics table on page 4 of DS46145 Rev. 2–2.

Does the AH3724-W-7 require an external capacitor on VDD?

Yes - a 10nF to 100nF ceramic decoupling capacitor (CIN) is required between VDD and GND, as specified in the Typical Applications Circuit (page 3). This stabilizes the internal bandgap regulator and improves RF noise immunity; omission risks erratic switching or startup failure under fast-rising supply conditions.

Can the AH3724-W-7 operate from a 3.3V supply in low-power systems?

Yes - the device is fully specified from 3.0V to 28V, including all electrical parameters (e.g., V_{OUT_ON} ≤0.4V at 20mA, I_DD ≤5mA) across –40°C to +125°C. At 3.3V, startup time remains ≤10µs and magnetic thresholds retain full hysteresis (80G typ), enabling use in battery-powered or energy-harvesting sensor nodes.

Is the SC59 package of AH3724-W-7 pin-compatible with SOT-23 Hall sensors?

No - although both are 3-pin surface-mount packages, SC59 has 0.95mm lead pitch and 3.0mm × 1.6mm body dimensions, whereas standard SOT-23 measures 2.9mm × 1.3mm with 0.95mm pitch but different lead form and die orientation. Pin 1 location and thermal pad layout differ; direct PCB footprint substitution is not possible without redesign.