Industrial Electronics

Allegro MicroSystems expands portfolio of three-phase sensorless BLDC gate drivers for data center cooling systems

25 May 2022

Allegro MicroSystems, Inc. has expanded its portfolio of three-phase sensorless brushless DC (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 size and increases time to market.

Source: Allegro MicroSystems, Inc.Source: Allegro MicroSystems, Inc.

Addressing these pain points, the A89332’s integrated power loss brake 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 quad flat no-lead package that is 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. The devices are available in a 26-contact 4 mm × 4 mm quad flat no-lead package with exposed thermal pad (suffix EX) and are lead-free, with 100% matte-tin lead-frame plating.

To contact the author of this article, email

Powered by CR4, the Engineering Community

Discussion – 0 comments

By posting a comment you confirm that you have read and accept our Posting Rules and Terms of Use.
Engineering Newsletter Signup
Get the Engineering360
Stay up to date on:
Features the top stories, latest news, charts, insights and more on the end-to-end electronics value chain.
Weekly Newsletter
Get news, research, and analysis
on the Electronics industry in your
inbox every week - for FREE
Sign up for our FREE eNewsletter
Find Free Electronics Datasheets