Allegro MicroSystems Expands Portfolio of Three-Phase Sensorless BLDC Gate Drivers for Data Center Cooling Systems

May 25, 2022
A89332 Code-Free Gate Driver for Data-Centers

New devices improve thermal efficiency, reducing energy use and data center costs

Manchester, NH, USA ­– Allegro MicroSystems, Inc. (“Allegro”) (Nasdaq: ALGM), a global leader in sensing and power solutions for motion control and energy-efficient systems, today announced it has expanded its portfolio of three-phase sensorless BLDC gate drivers. Its newest offerings, the A89332 and A89332-1, are designed to meet the evolving needs of cooling systems in today’s data centers offering flexible options for designers. Available with innovative integrated power loss brake (A89332) and AC-loss (A89332-1) features, these drivers enable compact, high-airflow fan designs to improve thermal efficiency, reducing energy use and data center costs. 

When server fans malfunction or break, backflow causes them to go into reverse rotation. The other fans have to work harder to compensate for the resulting airflow, which increases power consumption. The traditional solution to preventing reverse rotation is adding external circuitry and components to function as the power loss brake—components that do not fit into 1U fans. This approach requires software coding, increases bill of material (BoM) size, and increases time to market. 

Addressing these pain points, the A89332’s integrated power loss brake (PLB) function applies a brake to fans that aren’t working properly and stops them from spinning, with braking performance that’s four times better than discrete implementations. This eliminates unnecessary power consumption and increases thermal efficiency, ultimately reducing data center costs. When combined with the A89332-1’s AC loss logic, Allegro is now able to serve the high-end server market with the industry’s smallest gate driver, offered in a 4 mm x 4 mm QFN package that’s 36% smaller than comparable options—perfect for “donut” circuit boards.

Allegro offers the industry’s only code-free solutions for server cooling fans; the company’s innovative embedded algorithms and graphical user interface (GUI) eliminate the need for an additional Hall-effect position sensor and motor control unit (MCU), and no additional software development is required. This helps system designers reduce R&D overhead, simplify motor tuning, and improve time to market. The reduced need for external components further helps optimize system cost and improve reliability, and integrated functionality gives customers increased flexibility when faced with tight design requirements.

Both gate drivers build on Allegro’s history and experience developing unique motor control devices for the automotive and industrial markets. With more than three billion shipped in the last decade, the company’s trusted and reliable motor drivers have helped manufacturers innovate safer, more robust motor-drive solutions with increased reliability. They can be found across automotive, industrial, and consumer applications in products ranging from electric vehicles to cordless power tools to vacuum cleaners.

“The need to build data centers that operate more sustainably and consume less power is accelerating,” says Andy Wang, Product Line Director for I&O Motors at Allegro. “It’s not just about building low-maintenance ‘lights-out’ facilities; server and component designers are looking for new and novel ways to reduce heat and power consumption, and fans play a big role. We’ve been focusing on the data center market for some time, and with the addition of the A89332 and A89332-1, we’re giving them improved control over their cooling systems for maximum efficiency.”

Both devices are available in a 26-contact 4 mm × 4 mm QFN package with exposed thermal pad (suffix EX). These packages are lead (Pb) free, with 100% matte-tin leadframe plating. For product pricing and samples, contact an Allegro sales office or authorized distributor. For datasheets and more information on Allegro’s gate drivers, including the new A89332 and A89332-1, please visit the Allegro website.

About Allegro MicroSystems

Allegro MicroSystems (Nasdaq: ALGM) is redefining the future of sensing and power technologies. From green energy to advanced mobility and motion control systems, our team is passionate about developing intelligent solutions that move the world forward and give our customers a competitive edge. With global engineering, manufacturing and support, Allegro is a trusted partner to both large enterprises and regional market leaders worldwide. Visit