Diodes Incorporated AH3724A-W-7

Overview

AH3724A-W-7 from Diodes Incorporated is a high-voltage, high-sensitivity bipolar Hall-effect latch IC with internal pullup resistor, designed for brushless DC motor commutation and position sensing in industrial and consumer appliances. It operates from 3.0V to 28V, features BOP/BRP of 20–60G / –60G to –20G, delivers 30–55mA output current limit, and is housed in SC59 package rated for –40°C to +125°C.

For engineers reviewing the AH3724A-W-7 datasheet, AH3724A-W-7 pinout, AH3724A-W-7 application, or AH3724A-W-7 equivalent, this page provides verified magnetic thresholds, internal pullup resistance (10–18kΩ), chopper-stabilized temperature stability, Zener-clamped supply protection, and output overcurrent limiting - all critical for robust BLDC rotor position detection and RPM measurement in high-noise environments.

Technical Context

The AH3724A-W-7 implements a chopper-stabilized architecture with dynamic offset cancellation to minimize switch-point drift across temperature and stress. Its internal bandgap regulator supplies temperature-compensated bias to analog circuitry, enabling stable operation from –40°C to +125°C.

It functions as a bipolar latch: South pole exposure switches output low (V_{OUT_ON} ≤ 0.4V @ 20mA), North pole exposure releases it (I_{OUT_OFF} < 10µA). Hysteresis (B_HY) is 40–120G, ensuring noise immunity during magnetic transitions in rotating systems.

Key Specifications

Pinout & Package

SC59 package: 3-pin surface-mount, lead-free, RoHS-compliant, moisture sensitivity level 1 per J-STD-020. Dimensions: 2.80 × 2.40 × 0.95 mm (L × W × H), with 0.95 mm body height and 0.89 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL3724QSA-7, AH3724A-W-7 offers lower unit cost and identical functional performance for non-automotive applications; compared with US1881EUA-AAA-000, it adds bipolar latching, internal pullup, and higher ESD robustness - essential for closed-loop motor control and noisy industrial environments.

Availability

AH3724A-W-7 is available at Aetrix Electronics and suitable for brushless DC motor commutation, RPM measurement, linear encoder feedback, and contactless position sensing requiring stable component supply across industrial automation, home appliance, and personal care product lifecycles.

Supply support for AH3724A-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 sensor applications.

The AH3724A-W-7 belongs to Diodes' high-voltage Hall-effect latch product line, engineered specifically for reliable magnetic position detection in harsh, wide-input-voltage environments such as motor drives and flow instrumentation.

FAQ

What is the difference between AH3722A and AH3724A?

AH3724A has higher magnetic sensitivity: BOP/BRP of 20–60G / –60G to –20G versus AH3722A's 10–40G / –40G to –10G. This allows AH3724A to operate reliably with weaker magnets or larger air gaps, making it preferred for compact BLDC motors and miniaturized flow sensors where magnetic field strength is constrained.

Can AH3724A-W-7 drive an LED directly?

No. While its output can sink up to 55mA, the device lacks current regulation and thermal shutdown for sustained LED drive. It is designed for logic-level interfacing - connect to a microcontroller input or buffer transistor. For direct LED control, add a series current-limiting resistor and verify power dissipation does not exceed 550mW in SIP-3 or 230mW in SOT23/SC59 packages.

Is the internal pullup resistor temperature-stable?

Yes. The internal pullup resistor (10–18kΩ) varies less than ±15% over –40°C to +125°C, as confirmed by characterization data in DS46146 Rev. 1–2 Figure 6. This stability ensures consistent rise time and logic threshold margin across automotive and industrial temperature ranges without external compensation.

Does AH3724A-W-7 require an external bypass capacitor?

Yes. A 0.1µF ceramic capacitor between VDD and GND is required per the Recommended Operating Conditions table (DS46146 p.3). This stabilizes the internal bandgap regulator and suppresses supply noise coupling into the chopper amplifier - omission causes erratic switching or increased jitter in high-EMI environments like motor inverters.