Diodes Incorporated AH3725-SA-7

Overview

AH3725-SA-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 BOP/BRP of 50–90G / –90––50G (typ), delivers open-drain output with 30–55mA current limit, and is qualified for –40°C to +125°C operation in SOT23 (Type S) package.

For engineers reviewing the AH3725-SA-7 datasheet, AH3725-SA-7 pinout, AH3725-SA-7 application, or AH3725-SA-7 equivalent, key selection criteria include magnetic sensitivity hysteresis (100–180G), chopper-stabilized temperature stability, reverse supply protection (–18V), zener-clamped output, and compatibility with high-noise motor control environments.

Technical Context

The AH3725-SA-7 implements a chopper-stabilized architecture with dynamic offset cancellation to minimize switch-point drift over temperature and supply voltage. Its internal bandgap regulator supplies temperature-compensated bias to analog blocks, enabling stable BOP/BRP performance across –40°C to +125°C.

It uses a single-pole latching mechanism: South pole exposure switches the open-drain output low (V_{OUT_ON} ≤ 0.4V @ 20mA); North pole exposure releases it (I_{OUT_OFF} < 10µA). The device integrates reverse-blocking diode, supply zener clamp (28V), and output overcurrent limit (30–55mA).

Key Specifications

Pinout & Package

Supplied in industry-standard SOT23 (Type S) package (3-pin, surface-mount), with 2.90mm × 2.40mm footprint, 1.00mm height, and lead-free, RoHS-compliant construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with A1220LLHLT-T and US1881EUA-ABA-002-SP, the AH3725-SA-7 offers higher magnetic sensitivity (70G), wider supply range (up to 28V), integrated reverse and output protection, and superior temperature stability-making it the optimal choice for demanding BLDC and automotive position sensing where reliability and field margin are critical.

Availability

AH3725-SA-7 is available at Aetrix Electronics and suitable for brushless DC motor control, industrial flow metering, and automotive angular position sensing requiring stable component supply across extended temperature and voltage ranges.

Supply support for AH3725-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and sensing solutions for automotive, industrial, and computing markets.

The AH372X series belongs to Diodes' high-voltage Hall-effect sensor product line, engineered specifically for robust magnetic position and speed detection in electrically noisy, thermally demanding environments such as motor drives and vehicle subsystems.

FAQ

What is the magnetic polarity response of the AH3725-SA-7?

The AH3725-SA-7 is a bipolar latch: it turns ON (pulls OUTPUT low) when exposed to a South pole of sufficient strength (≥70G at marking side), and remains latched until a North pole of sufficient strength (≤–70G) is applied to release it. This behavior is confirmed in the magnetic characteristics table for AH3725 and validated across –40°C to +125°C.

Does the AH3725-SA-7 require an external pull-up resistor?

Yes - the AH3725-SA-7 has an open-drain OUTPUT pin and requires an external pull-up resistor to define the high-state voltage level. Typical values range from 1kΩ to 10kΩ depending on rise time and bus voltage; the datasheet recommends RL with V_PULLUP ≤ 28V and accounts for t_R = 0.2–1µs at RL = 1kΩ and C_L = 20pF.

Can the AH3725-SA-7 operate directly from a 24V truck battery?

Yes - the AH3725-SA-7 is rated for continuous operation from 3.0V to 28V and withstands reverse supply transients down to –18V. Its integrated reverse-blocking diode and supply zener clamp ensure safe operation during load-dump or jump-start conditions common in 24V commercial vehicle systems.

Is the AH3725-SA-7 pin-compatible with other AH372X variants?

Yes - all AH372X devices (AH3722, AH3724, AH3725, AH3727) share identical pinout (VDD-GND-OUTPUT) and SOT23 (Type S) package dimensions. Only magnetic thresholds differ; electrical interface, protection features, timing, and thermal specs are fully consistent across the family.