Evaluation kit for 3-phase brushless DC motor driver

December 04, 2013 // By Graham Prophet
Allegro MicroSystems Europe has a product evaluation kit to assist the design process for the company’s A4915 3-phase MOSFET controller IC.

The evaluation kit consists of a printed-circuit board containing everything required to spin and control a brushless DC (BLDC) motor. All the user has to do is provide a voltage supply and the motor itself.

The A4915 incorporates on-chip Hall commutation and a unique speed control input, which takes an analogue voltage and generates a pulse-width-modulated (PWM) output with a variable duty cycle.

This arrangement makes it possible to efficiently control a BLDC motor with little or no microprocessing power, resulting in a 75% reduction in PCB space compared with alternative solutions.

The A4915 evaluation kit operates up to 50V and includes everything needed to spin a motor. Six all N-channel power MOSFETs are mounted on the evaluation kit and can supply 30A peak and 20A nominal run current at room temperature. If larger loads are needed, the A4915 has jumpers that disable the onboard bridge and provide connections for an external bridge. An onboard 5V regulator creates the secondary supply for logic inputs. This development kit is targeted at both the industrial and consumer markets.

The A4915 development kit is available for both the 28-pin TSSOP with an exposed thermal pad (suffix LP) and a 28-contact 5 x 5 mm QFN with an exposed thermal pad (suffix ET).

Allegro MicroSystems; www.allegromicro.com