Diodes Incorporated AH3724-P-A

Overview

AH3724-P-A from Diodes Incorporated is a high-voltage, bipolar Hall-effect latch IC designed 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, and delivers BOP/BRP of 20–60G / –60––20G (typ) with 40–120G hysteresis. Its chopper-stabilized architecture ensures stable switching across –40°C to +125°C.

For engineers reviewing the AH3724-P-A datasheet, AH3724-P-A pinout, AH3724-P-A application, or AH3724-P-A equivalent, key selection criteria include magnetic sensitivity thresholds, supply voltage range, open-drain drive capability, thermal stability over automotive temperature extremes, and SIP-3 (Ammo Pack) package compatibility with through-hole PCB assembly.

Technical Context

The AH3724-P-A implements a chopper-stabilized Hall sensor with dynamic offset cancellation, enabling minimal switch-point drift (<±0.1G/°C typical) and superior immunity to mechanical stress and thermal gradients. Its internal bandgap regulator supplies temperature-compensated bias to analog circuitry, decoupling performance from VDD fluctuations.

It uses a bipolar latching mechanism: South pole exposure switches the open-drain output low (V_{OUT_ON} ≤ 0.4V @ 20mA), and North pole exposure releases it (I_{OUT_OFF} < 10µA). The device integrates reverse-blocking diode and zener clamp on VDD, plus output overcurrent limit and ESD protection (8kV HBM).

Key Specifications

Pinout & Package

Package: SIP-3 (Ammo Pack) - 3-pin single-inline package with spread leads, optimized for automated through-hole insertion and high-reliability solder joints in harsh-environment PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL3724QSA-7 and US1881LUA-AAA-000, AH3724-P-A provides optimal balance of industrial-grade ruggedness (28V operation, integrated clamps), SIP-3 manufacturability, and cost-making it ideal for non-automotive BLDC and position-sensing applications requiring field-proven reliability without automotive certification overhead.

Availability

AH3724-P-A is available at Aetrix Electronics and suitable for brushless DC motor commutation, RPM measurement, and flow meter sensing requiring stable component supply across extended temperature and voltage ranges.

Supply support for AH3724-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 industrial, automotive, and computing markets.

The AH372X series targets high-reliability magnetic sensing in demanding environments, with the AH3724 variant optimized for mid-sensitivity applications like general-purpose BLDC commutation and industrial RPM monitoring.

FAQ

What is the recommended pull-up resistor value for the AH3724-P-A output?

A 1kΩ to 10kΩ pull-up resistor is recommended depending on rise time requirements and supply voltage. For 24V systems with RL = 4.7kΩ, t_R remains <1µs (CL = 20pF), ensuring compatibility with 1MHz microcontroller input capture. Lower values improve speed but increase quiescent current when output is low.

Can AH3724-P-A operate reliably at 3.0V supply?

Yes - the device is fully specified from 3.0V to 28V. At 3.0V, BOP/BRP remain within 20–60G / –60––20G, startup time is 10µs, and V_{OUT_ON} stays ≤ 0.4V at 20mA. Supply current is 3–5mA across –40°C to +125°C, making it suitable for battery-powered or low-voltage industrial nodes.

Does AH3724-P-A require an external bypass capacitor?

Yes - a 10nF to 100nF ceramic capacitor (C_IN) between VDD and GND is required per the datasheet. It stabilizes the internal bandgap regulator and improves RF noise immunity. Placement within 3mm of the VDD/GND pins is critical to maintain chopper stabilization performance and prevent erratic switching.

How does the SIP-3 (Ammo Pack) package differ from SOT23 or SC59 variants?

The SIP-3 (Ammo Pack) uses spread leads for through-hole mounting, offering higher mechanical retention and thermal mass than surface-mount SOT23/SC59. It supports higher reflow survivability and is preferred for high-vibration environments like motor controllers. Pinout (VDD-GND-OUTPUT) matches all AH372X packages, enabling direct footprint substitution in legacy designs.