Three-phase BLDC fan-motor driver employs resistor-programmable, sensorless sinusoidal architecture

The PC fan may not be as glamorous as the active components, but managing it—and minimizing its power usage—are critical to the overall system design, cooling, and run time. Microchip Technology claims that its MTD6505 fan-motor driver is the first standalone, resistor-programmable driver that enables the selection of multiple back-EMF coefficient ranges. 

The MTD6505 fan-motor driver from Microchip Technology

uses a resistor-programmable, sensorless sinusoidal architecture

and so can be tailored to many fan models.

As a result, engineers can design-in a single device to match a wide variety of 3-phase BLDC (brushless DC) fan characteristics with a single device. Since footprint is a critical factor as well (when isn't it?), the driver comes in a 3×3 mm UDFN package with a 0.5 mm thickness, well-suited to space-constrained applications, such as thin laptops and tiny BLDC fans.

For high energy efficiency and quiet operation with low acoustic noise and mechanical vibration, the MTD6505 includes a 180-degree sinusoidal drive.  As a sensorless driver, the MTD6505 eliminates the need for an external Hall-effect sensor, reducing both cost and board space.  It also includes on-chip protection features to preserve the motor’s life and avoid harmful operating conditions, including thermal shutdown, over-current limiting and lock-up protection.

Development Support: the MTD6505 3-Phase BLDC Sensorless Fan Controller Demonstration Board (part # ADM00345, $59.99) will be available in January for $59.99. This board comes with a 3-phase BLDC fan and three MTD6505 plug-in modules.  Additionally, a free GUI is available for download that simplifies fan monitoring and control with the onboard PIC^® microcontroller.

Pricing & availability: The MTD6505 motor driver is sampling now in a 10-pin UDFN package. Pricing in 5,000-unit pricing is $0.57 each. 

For more information: For the MTD6505 motor driver, go to http://www.microchip.com/get/2B02; for the demonstration board, go to http://www.microchip.com/get/T560