Three-phase sensorless BLDC gate drivers cool data centres
Additions to Allegro Microsystems’ three-phase sensorless brushless DC (BLDC) gate drivers, the A89332 and A89332-1 improve thermal efficiency, reduce energy use and data centre costs, claims the company.
The A89332 and A89332-1 are designed for cooling systems in today’s data centres. The A89332 is available with integrated power loss brake while the A89332-1 has AC-loss features. Both drivers enable compact, high airflow fan designs, said Allegro Microsystems.
When server fans malfunction or break, backflow causes them to go into reverse rotation. Other fans have to work harder to compensate, which increases power consumption. Conventional solutions to prevent reverse rotation involve adding external circuitry and components to function as the power loss brake. The components however do not fit into 1U fans and require software coding. This approach also increases bill of material (BoM) costs and increases time to market, said Allegro.
Its solution is the A89332’s integrated power loss brake (PLB) function which applies a brake to fans that are not working properly and stops them from spinning. The result is braking performance that is four times better than discrete implementations. This eliminates unnecessary power consumption and increases thermal efficiency, said Allegro, ultimately reducing data centre costs. When combined with the A89332-1’s AC loss logic, the gate drivers in a 4.0 x 4.0mm QFN package are suitable for the high-end server market and in a form factor that is 36 per cent smaller than comparable options and “perfect for “donut” circuit boards” said the company.
Allegro said it offers the industry’s only code-free solutions for server cooling fans. Its embedded algorithms and graphical user interface (GUI) eliminate the need for an additional Hall-effect position sensor and motor control unit with no additional software development required.
“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’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,” he continued.
The A89332 and A89332-1 offer developers improved control over their cooling systems for maximum efficiency, said Wang.
Both devices are available in a 26-contact 4.0 x 4.0mm QFN package with exposed thermal pad (suffix EX). The packages are lead (Pb) -free, with 100 per cent matt-tin leadframe plating
Allegro MicroSystems provides sensing and power technologies for green energy to advanced mobility and motion control systems. The company offers global engineering, manufacturing and support.
