Diodes Incorporated AH3722-W-7

Overview

AH3722-W-7 from Diodes Incorporated is a high-voltage bipolar Hall-effect latch IC designed for brushless DC motor commutation and RPM sensing in automotive and industrial systems. It operates from 3.0V to 28V, features ±25G to ±40G magnetic operate/release points (BOP/BRP), delivers <0.4V output saturation at 20mA, and supports -40°C to +125°C ambient operation with 8kV HBM ESD rating.

For engineers reviewing the AH3722-W-7 datasheet, AH3722-W-7 pinout, AH3722-W-7 application, or AH3722-W-7 equivalent, key selection criteria include its SC59 package compatibility, open-drain output with 30–55mA current limiting, chopper-stabilized temperature stability, reverse supply protection (-18V), and zener-clamped output stage for robust magnetic position sensing in noisy environments.

Technical Context

The AH3722-W-7 implements a chopper-stabilized Hall sensor architecture with dynamic offset cancellation, enabling minimal switch-point drift over temperature and superior immunity to mechanical stress and thermal gradients. Its internal bandgap regulator supplies temperature-compensated bias to all analog blocks, ensuring stable BOP/BRP thresholds across the full -40°C to +125°C range.

It integrates a reverse-blocking diode and zener clamp on VDD, plus output-stage overcurrent limiting and zener clamping-providing system-level protection against supply transients, back-EMF, and load faults. The single open-drain output latches ON with sufficient South-pole flux (>25G) and releases only when North-pole flux drops below -25G, delivering clean, hysteresis-controlled digital switching.

Key Specifications

Pinout & Package

Package: SC59 (3-pin, single-inline, leaded surface-mount). Dimensions per Diodes Inc. outline SC59: A=0.35–0.50mm, B=1.50–1.70mm, C=2.70–3.00mm, H=2.90–3.10mm, L=0.35–0.55mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL3722QSA-7, AH3722-W-7 offers identical core functionality at lower qualification cost for non-automotive use; versus US5781LSE-7, it provides superior supply ruggedness, tighter magnetic thresholds, and broader temperature margin-critical for industrial motor control.

Availability

AH3722-W-7 is available at Aetrix Electronics and suitable for brushless DC motor commutation, RPM measurement, and flow metering requiring stable component supply across automotive, industrial, and appliance design cycles.

Supply support for AH3722-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 company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and sensing applications.

The AH372X series targets high-reliability magnetic sensing in harsh environments, with the AH3722 variant optimized for medium-sensitivity applications such as mid-power BLDC motors and precision RPM feedback loops.

FAQ

What is the magnetic polarity behavior of the AH3722-W-7?

The AH3722-W-7 is a bipolar latch: a South pole applied to the marked side switches the open-drain output ON (low), and a North pole of sufficient strength releases it to high-impedance. The device holds its state until the opposite pole exceeds the release point (BRP = -25G typ), providing nonvolatile position memory without continuous power.

Can AH3722-W-7 operate directly from a 24V truck battery?

Yes. Its 3.0V–28V operating range and integrated -18V reverse-supply protection allow direct connection to 24V systems. The VDD zener clamp limits transients to 28V, and the 32V absolute maximum rating accommodates load-dump spikes per ISO 7637-2, eliminating need for external TVS diodes in most vehicle applications.

What external components are required for stable operation?

A 10nF–100nF ceramic bypass capacitor (CIN) between VDD and GND is mandatory for power stabilization and noise immunity. A pull-up resistor (RL) on the OUTPUT pin is required-value depends on rise time needs and logic rail (e.g., 4.7kΩ for 3.3V, 10kΩ for 24V). No additional filtering or compensation is needed due to chopper stabilization.

How does the AH3722-W-7 differ from AH3724-W-7 in practical use?

AH3722-W-7 has lower magnetic sensitivity (BOP ±25G typ) than AH3724-W-7 (±40G typ), making it ideal for applications using stronger magnets or requiring reduced false-triggering in stray-field environments. Its narrower hysteresis (50G vs. 80G) enables finer position resolution but demands more precise magnet placement in encoder designs.