Three-phase sensorless BLDC gate driver portfolio for data centre cooling systems

Allegro MicroSystems, Inc has expanded its portfolio of three-phase sensorless BLDC gate drivers. Its most recent offerings, the A89332 and A89332-1, are developed to satisfy the evolving demands of cooling systems in today's data centres delivering flexible options for designers. Offered with innovative integrated power loss brake (A89332) and AC-loss (A89332-1) features, these drivers provide compact, high-airflow fan designs to enhance thermal efficiency, lowering energy use and data centre costs.

When server fans malfunction or break, backflow forces them to go into reverse rotation. The other fans have to operate harder to compensate for the resultant airflow, which raises power consumption. The conventional solution to stopping 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 needs software coding, increases BoM size, and increases time to market.

Meeting these pain points, the A89332's integrated PLB function applies a brake to fans that are not working correctly and stops them from spinning, with braking performance that is four times better than discrete implementations. This eradicates unnecessary power consumption and improves thermal efficiency, ultimately reducing data centre costs. When incorporated with the A89332-1's AC loss logic, the company can serve the high-end server market with gate drivers delivered in a 4mm x4mm QFN package that is 36% smaller than similar options – ideal for 'donut' circuit boards.

The company provides the industry's only code-free solutions for server cooling fans; its innovative embedded algorithms and GUI eradicate the demand for an extra Hall-effect position sensor and MCU, requiring no extra software development. This enables system designers to reduce R&D overhead, simplify motor tuning, and improve time to market.

The need to build data centres that operate more sustainably and consume less power is accelerating," says Andy Wang, product line director for Motors (Industrial) at Allegro. "It is 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 centre market for some time, and with the addition of the A89332 and A89332-1, we are giving them improved control over their cooling systems for maximum efficiency."