Three-Phase Sensorless Drivers

A89331, A89331-1, A89332, A89332-1, A89332-3


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


Top Features


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.

  • 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

Typical Applications

Server and Data-center Cooling Fans

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

EX Package Documentation


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

ET Package Documentation


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

LP Package Documentation

Part Number Specifications and Availability

Documentation and Resources


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