A89331, A89331-1, A89332, A89332-1: Three-Phase Sensorless Drivers

NEW: The A89332 and A89332-1 enable faster, high speed 1U fans all in a smaller, compact footprint.

Please contact us for the full datasheets of the A89331, A89331-1, A89332 and A89332-1.


The A89332 three-phase sensorless fan controller helps reduce data-center costs. With power loss brake function, the A89332 gate driver IC can reduce energy consumption by stopping fans that have lost power or are not working properly.

The A89332 is available in a 26-contact 4 mm x 4 mm QFN with exposed pad (suffix EX).

The A89331 three-phase motor driver with integrated MOSFETs offers sensorless control, eliminating the requirement for Hall sensors in server fan applications. The A89331 incorporates a sensorless sinusoidal driver to minimize vibration for high-speed server fans.

The A89331 is available in a 28-contact 5 mm x 5 mm QFN with an exposed power pad (suffix ET) and a 20-contact TSSOP with an exposed power pad (suffix LP).

As the leading code-free solution for data-center cooling fans, these drivers are integrated with a flexible closed-loop speed control system. An EEPROM is used to tailor the common functions of the fan speed curve to a specific application. This eliminates the requirement for a microprocessor-based system and minimizes programming requirements.

Top Features

  • Closed Loop Speed Control
  • Overvoltage Protection
  • Power Loss Brake – A89331, A89332
  • AC Loss – A89331-1, A89332-1
  • High Maximum Voltage (36 V) A89332, A89332-1
  • Sized for 1U and 2U Fans

Featured Applications

Server and Data-center Cooling Fans

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A89331GETSR 28-lead QFN -40°C to 105°C Yes View Data Contact your
local sales rep
Distributor Stock
A89331GETSR-1 28-lead QFN -40°C to 105°C Yes View Data Contact your
local sales rep
Distributor Stock
A89331GLPTR-T 20-lead TSSOP -40°C to 105°C Yes View Data Contact your
local sales rep
Distributor Stock
A89332GEX 26-lead QFN -40°C to 105°C -- View Data New Contact your
local sales rep
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.


Allegro EX 26 package

26-contact QFN with exposed thermal pad (suffix EX)

EX Package Documentation


28-contact QFN with exposed thermal pad (suffix ET)

ET QFN with exposed pad 28 lead

ET Package Documentation


20-contact TSSOP with exposed thermal pad (suffix LP)

20-Pin eTSSOP with exposed thermal pad LP Package

LP Package Documentation

Design Support Tools

Allegro Customer Portal: Gain access to Allegro product software and design tools.


Code-Free Gate Drivers for Data-Center Cooling Fans