Diodes Incorporated AH289-PL-B

Overview

AH289-PL-B from Diodes Incorporated is a monolithic high-voltage Hall-effect smart fan motor controller with integrated on-chip Hall sensor, dual complementary open-drain output drivers (DO/DOB), rotor-state detection (RD) output, and automatic rotor-lock shutdown/restart protection. It operates from 3.8V to 28V, delivers 400mA average output current, and is housed in a SOT89-5L package. It is used in 24V DC brushless cooling fans requiring stall detection and self-recovery.

For engineers reviewing the AH289-PL-B datasheet, AH289-PL-B pinout, AH289-PL-B application, or AH289-PL-B equivalent, key selection considerations include its Hall-based commutation logic, RD output polarity (low during rotation), locked-rotor timeout (0.46s ON / 2.76s OFF), Zener-protected outputs, and thermal derating above 25°C.

Technical Context

The AH289 implements latch-type Hall sensing with B_OP = 10–60 G and B_RP = −60 to −10 G hysteresis, enabling robust rotor position detection under varying temperature and voltage. Its control logic autonomously disables DO/DOB outputs upon rotor lock and initiates periodic restart attempts.

It integrates a linear regulator for internal biasing, thermal shutdown at T_J = 150°C, and built-in Zener clamping (V_Z = 42–65 V) on both output pins to suppress inductive kickback. The RD pin provides open-drain status signaling with VOL ≤ 0.5 V at I_OL = 10 mA.

Key Specifications

Pinout & Package

SOT89-5L surface-mount package with exposed thermal pad; 5-pin configuration optimized for compact fan module integration and thermal management.

Key Features

Applications

Availability

AH289-PL-B is available at Aetrix Electronics and suitable for server cooling systems, industrial control cabinets, medical power supplies, and telecom base station thermal management requiring stable component supply and long-lifecycle support.

Supply support for AH289-PL-B 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 power management, signal integrity, and precision analog solutions for industrial, computing, and communications markets.

The AH289 belongs to Diodes' smart motor controller product line, designed specifically for cost-sensitive, high-reliability brushless DC fan applications requiring integrated Hall sensing and autonomous fault recovery.

FAQ

What is the function of the RD pin, and how should it be interfaced?

The RD pin is an open-drain output that goes low during normal rotation and high during rotor stall. It requires an external pull-up resistor (typically 10 kΩ to Vdd) and connects directly to a microcontroller GPIO. Its latch-type behavior eliminates need for debouncing; firmware reads state to detect blockage without polling timing constraints.

Does AH289-PL-B support PWM speed control?

No-AH289-PL-B does not accept external PWM input. Speed is determined solely by supply voltage and motor winding characteristics. It provides fixed-frequency, Hall-commutated drive with automatic lock protection but no user-adjustable speed modulation.

Can AH289-PL-B drive a 48 V fan?

No-absolute maximum Vdd is 30 V, and recommended operating range is 3.8 V to 28 V. Driving a 48 V fan would exceed ratings and damage the device. For 48 V systems, external step-down regulation to ≤28 V is required before connecting to Vdd.

Is AH289-PL-B pin-compatible with any newer Diodes replacement?

No-Diodes explicitly states "NOT RECOMMENDED FOR NEW DESIGN – NO ALTERNATE PART" in the datasheet. There is no designated drop-in or functional replacement; new designs require re-evaluation with alternative motor controllers such as the AP22801 or similar third-party Hall drivers.