Diodes Incorporated AH3724A-SA-7

Overview

AH3724A-SA-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 <0.4V output saturation at 20mA, and supports –40°C to +125°C ambient operation in SOT23 (Type S) package.

For engineers reviewing the AH3724A-SA-7 datasheet, AH3724A-SA-7 pinout, AH3724A-SA-7 application, or AH3724A-SA-7 equivalent, this page provides verified magnetic thresholds, chopper-stabilized timing behavior, internal pullup value (10–18kΩ), output current limit (30–55mA), and package-specific thermal derating data for motor control and flow meter designs.

Technical Context

The AH3724A employs chopper-stabilized architecture with dynamic offset cancellation and an internal bandgap regulator to deliver temperature-compensated switching across –40°C to +125°C. Its bipolar latch logic requires South pole activation (B > +20G typical) and North pole deactivation (B < –20G typical), with hysteresis of 40–120G ensuring noise-immune state retention.

It integrates supply Zener clamping (28V), output overcurrent limiting, reverse-blocking diode, and ESD protection (8kV HBM). The internally pulled-up open-drain output switches low when latched on, eliminating external pullup components in 3.0–28V systems.

Key Specifications

Pinout & Package

Package: SOT23 (Type S), 3-pin surface-mount, 2.9mm × 2.4mm footprint, 0.95mm max height, matte tin-plated leads, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AH3724A-SA-7, AL3724QSA-7 adds automotive qualification overhead without performance gain, while US1881EUA-AAA-7 trades sensitivity and integration for ruggedness-making AH3724A-SA-7 optimal for cost-sensitive, high-volume industrial motion control where internal pullup and 40G sensitivity reduce system-level component count.

Availability

AH3724A-SA-7 is available at Aetrix Electronics and suitable for brushless DC motor commutation, flow meter sensing, and linear encoder position applications requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for AH3724A-SA-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 industrial, computing, and consumer markets.

The AH3724A belongs to Diodes' high-voltage Hall-effect latch product line, engineered specifically for robust, low-BOM-count position and speed sensing in harsh environments with wide supply and temperature ranges.

FAQ

What magnetic field strength is required to activate the AH3724A-SA-7?

The AH3724A-SA-7 activates (output goes low) when perpendicular magnetic flux density exceeds +20G (min), +40G (typical), or +60G (max) on the marked surface with South pole orientation. Deactivation occurs below –20G (min), –40G (typical), or –60G (max) with North pole. Hysteresis ensures stable state retention between thresholds.

Can the AH3724A-SA-7 operate directly from a 24V supply without external regulation?

Yes. The AH3724A-SA-7 is rated for continuous 3.0V to 28V operation and includes an internal Zener clamp at 28V on VDD. It draws only 3–5mA supply current across temperature, enabling direct connection to unregulated 24V industrial rails without external LDO or resistor dropper.

Does the internal pullup resistor eliminate all external components on the output pin?

Yes-the internal 10–18kΩ pullup resistor allows direct connection of the OUTPUT pin to standard CMOS/TTL inputs without external pullup. No additional resistor is needed unless driving high-capacitance loads (>100pF) or requiring faster rise times, in which case a parallel lower-value resistor may be added.

How does the chopper stabilization improve performance in motor control applications?

Chopper stabilization at 500kHz cancels offset voltage drift caused by temperature gradients and mechanical stress, reducing BOP/BRP shift to <±0.5G/°C. This ensures consistent commutation timing across motor temperature rise (e.g., from 25°C to 105°C), preventing torque ripple and acoustic noise in BLDC drives.